Orthopaedic Knowledge Home Study by R. Alexander

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 Figure 7 Ring finger delta phalanx. Figure 8 Constriction ring syndrome with web base separation. the level of the web space (Figure 8). The underlying nism. Camptodactyly has a bimodal type of distribution, structures are usually normal to the level of the digital with type I presenting in infancy and type II presenting absence; separation of digits may be easily performed as in adolescence. In type III, the condition is found as part the proper level of the web is already established. Cir- of a syndrome. cumferential rings may best be released by performing surgery on one half of the circumference at a time. On Most type I patients improve with stretching and rare occasion, this disorder may occur with significant splinting. Patients with type II camptodactyly may im- compromise to the digit distal to the site of the constric- prove with splinting and may have significant residual tion ring and will require release of the ring during the flexion deformity, as do type III patients. Surgery for first few days of life. In most patients with ring release, a this disorder must be undertaken with caution because deep fibrous layer must be excised in addition to significant residual flexion deformity is usually noted. Z-plasty, which is usually performed at the skin level. Most authors recommend reserving surgical release for contractures greater than 60°. Camptodactyly Syndactyly Camptodactyly is an isolated congenital flexion defor- Syndactyly is the most common congenital hand defor- mity of the proximal interphalangeal joint. The patients mity occurring in approximately 1 in 2,200 births. It may may present with a broad spectrum of deformity and in- be inherited with an autosomal dominant pattern in up volvement. The digits have abnormalities of numerous to 40% of patients. Although numerous syndromes in- structures including skin, fascia, tendon sheaths, flexor clude syndactyly, the most common are Apert’s syn- digitorum sublimis tendons, lumbrical and interosseous drome and Poland’s syndrome. Syndactyly may be com- muscles, bony surfaces, and the central extensor mecha- plete or incomplete based on the distal extent of the 724 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics Figure 9 Complete syndactyly of the third and fourth fingers. epiphyseal plate. A physeal bar has been found that bridges the distal metaphysis of the radius to the epi- web (Figure 9). Syndactyly is also classified as either physis along the volar aspect of the radius at the lunate simple or complex based on any component of shared facet. Hypertrophy of palmar ligaments (including the bone or nail. The geometry of most syndactylous digits radiotriquetral and the short radiolunate ligaments, and usually requires the use of skin graft for separation. A an anomalous volar ligament) has been identified. It ap- full-thickness graft harvested from either the upper ex- pears that the physeal bar impedes the normal develop- tremity or the groin provides adequate coverage. Recent ment of the distal radius causing its palmar and ulnar reports have promoted the separation of syndactylous deformity. The hypertrophied ligament also appears to fingers without grafting by the aggressive defatting of contribute to the deformity. skin flaps. Border digits may require early release be- cause of the disparate length of the ring and small finger Radiographic findings include dorsal bowing of the or the thumb and index finger. Complications of syndac- radius, ulnar tilting of the radius, and radial tilting of the tyly release include infection, web creep, and unrecog- ulna. There is palmar tilting of the distal articular sur- nized bony anomaly. Web creep is seen in patients un- face of the radius and a triangular appearance of the dergoing surgery before 16 months of age. The epiphysis. A fixed pronation deformity of the distal ra- unrecognized bony anomaly of a delta phalanx also may dius is usually present. be undetected on radiographs until 18 months of age. These two factors may indicate that delaying surgery Madelung’s deformity may occur as an isolated con- until 18 months may be advisable. dition or as part of a generalized dysplastic disorder as- sociated with Leri-Weill syndrome (dyschondrosteosis), Madelung’s Deformity a condition whose inheritance is autosomal dominant. Deletions or mutations in the SHOX (short stature ho- Madelung’s deformity is a growth disturbance involving meobox–containing) gene have now been well docu- the palmar and ulnar aspects of the distal radius at the mented in those patients. During the first few years of life, the ulnar portion of the epiphysis fails to ossify, leading to a severely angu- lated distal articular surface. The carpus then tends to shift toward the ulna with the lunate often overlapping the ulnar head. Patients may seek treatment during the preadolescent years because of the deformity. Pain is rarely a symptom. Numerous surgical approaches have been described. It appears that the palmar approach to release the hy- pertrophied ligament combined with either epiphysioly- sis or osteotomy may offer the best treatment for cor- recting this deformity. After epiphyseal plate closure, procedures to correct the deformity should include cor- rection of the articular surface angular deformity com- bined with ulnar shortening. Salvage type procedures in- clude radiolunate arthrodesis combined with distal ulnar resection. Synostosis of the Proximal Radius and Ulna Failure of the proximal radius and ulna to separate leads to a fixed forearm position because of synostosis. Most cases of synostosis are bilateral and may fre- quently occur in association with other organ system ab- normalities. In most patients the disease is characterized by a forearm that is in slight to moderate pronation; minimal treatment may be required for this condition. In patients with significant supination of the forearm, a rotational osteotomy is recommended so that both palms may be positioned for keyboard use. Reposition- ing of the forearm in patients with congenital radioulnar synostosis may be performed using an osteotomy through the level of synostosis or with a two-level os- American Academy of Orthopaedic Surgeons 725

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 Table 4 | Thumb Hypoplasia mately undergo pollicization to avoid placement of a pin through the index metacarpal. Type I Mild underdevelopment Type II Thenar hypoplasia, abduction contracture, metacarpopha- A recent long-term assessment of the functional out- langeal laxity come after centralization for radial dysplasia showed that Type III Thenar hypoplasia, abduction contracture, metacarpopha- despite surgical intervention, hand function remained langeal instability, extrinsic tendon hypoplasia or absence, markedly abnormal, whereas upper extremity disability A metacarpal underdevelopment was mild. Improvement of wrist alignment and increased B Stable carpometacarpal joint forearm length was not found to correlate with improved Type IV Unstable carpometacarpal joint upper extremity function. Significant radial angulation Type V Pouce flottant and limited range of motion and grip strength were all Complete absence of thumb findings in this long-term follow-up study. teotomy (one osteotomy performed at the distal third of Thumb Hypoplasia the radius and one at the proximal third of the ulna). Attempts to separate the synostosis have been success- Thumb hypoplasia includes the spectrum of deformities ful in a limited number of patients; the use of either a from a slightly small thumb to complete thumb absence. pedicled or free tissue transfer to prevent reformation Blauth type I thumbs usually appear small but require of the synostosis is required. no reconstruction. Type II deformities have absent or underdeveloped thenar muscles; opponensplasty is re- Transverse Forearm Deficiency quired. Type III hypoplastic thumbs are characterized by underdevelopment of the metacarpal bones, absence Most patients with transverse failure of formation have a of extrinsic tendons, and thenar hypoplasia. Type IIIA unilateral, short below-elbow deficiency. Other levels of thumbs show a stable carpometacarpal joint and type failure of formation include transcarpal, distal forearm, IIIB thumbs an unstable carpometacarpal joint, often and transhumeral. Most children will have excellent ad- with a deficient metacarpal. Type IIIA thumbs require aptation to this deficiency with few functional deficits. significant reconstructive effort including opponens- plasty, metacarpophalangeal joint stabilization, and web The use of a passive prosthesis is usually attempted space deepening. Type IIIB thumbs may best be treated in patients with a short below-elbow deficiency. In some by ablation and pollicization using the index finger as is patients, the forearm portion is quite short and there recommended for the type IV deficiency (pouce flot- may be difficulty with prosthetic fitting. In addition, tant). The type V deficiency is characterized by com- soft-tissue coverage may be inadequate to allow for plete absence of the thumb (Table 4). Studies of the prosthetic placement. Prosthetic fitting usually begins at long-term outcome following hypoplastic thumb recon- 4 to 6 months of age and includes a passive prosthesis to struction did not find any benefit from early reconstruc- allow for two-handed activity. Many children resist the tion. More than 30% of patients undergoing polliciza- use of a prosthesis because of its lack of sensory feed- tion will require opponensplasty. Pollicization is best back. More proximal levels of deficiency are rarely performed when the patient is 2 to 3 years old because treated with prosthetic usage. of the increased size of the digital vessels. Longitudinal Deficiency of the Radius Longitudinal Deficiency of the Ulna Radial ray deficiency is a condition occurring in 1 in Ulnar longitudinal deficiency is one fourth as common 25,000 births. Radial ray deficiencies include complete as radial ray deficiency and occurs in approximately 1 in or partial absence of the radius and radial digits—most 100,000 births. The ulna may show partial or complete commonly the thumb. Radial deficiencies are usually bi- deficiency with varying levels of digital deletions. The el- lateral. Radial ray deficiency has been categorized as bow deformity ranges from joint hypoplasia to complete type I, short distal radius; type II, underdevelopment of radiohumeral synostosis. Unilateral involvement is most the entire radius; type III, partial absence of radius; and common and this condition is frequently associated with type IV, complete absence of radius (the most common other musculoskeletal abnormalities such as scoliosis deficiency). Treatment includes passive stretching with and fibular deficiency. Surgical treatment of patients either serial casting or static progressive splinting until 6 with ulnar radial deficiency usually focuses on the hand. months of age at which time centralization or radializa- Up to three fourths of hands have first web abnormali- tion is performed. Alternatively, soft-tissue distraction ties. Syndactyly is frequently found in the digits that are using external fixation also may be used to provide present, and also requires separation. One study found some level of correction before bony stabilization. Cen- that slightly fewer than 50% of patients with ulnar ray tralization is usually performed in patients who will ulti- deficiency also displayed some element of thenar hypo- plasia. 726 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics Annotated Bibliography pared with only 10% requiring hospitalization when fractures occurred during the winter. Forearm and Wrist Trauma Waters PM, Bae D, Montgomery K: The surgical man- Boyd KT, Brownson P, Hunter JB: Distal radial frac- agement of post-traumatic distal radial physeal growth tures in young goalkeepers: A case for an appropriately arrest in adolescents. J Pediatr Orthop 2002;22:717-724. sized soccer ball. Br J Sports Med 2001;35:409-411. The authors present a case study of patients with distal ra- In a prospective, clinic-based study of young goalkeepers, dial physeal arrests with consequential ulnar overgrowth re- it was shown that the size of the ball had a direct effect on the sulting in complications with ulnar-carpal impaction, distal risk of a distal radius fracture. radial-ulnar joint incongruity, and triangular fibrocartilage tears. Surgical planning and treatment options are outlined for Cannata G, DeMaio F, Mancini F, Ippolito E: Physeal corrective osteotomies and soft-tissue repairs. fractures of the distal radius and ulna: Long-term prog- nosis. J Orthop Trauma 2003;17:172-179. Hand Trauma One hundred sixty-three fractures of the distal radius and Mahabir RC, Kazemi AR, Cannon WG, et al: Pediatric ulna physes in 157 patients were reviewed at an average hand fractures: A review. Pediatr Emerg Care 2001;17: follow-up of 25.5 years (14 to 46 years). Seventy-seven were 153-156. isolated fractures of the distal radius, 54 were associated with ulnar styloid fractures, and 26 were associated with ulnar The incidence and epidemiology of hand fractures in chil- metaphyseal fractures. Eighteen were Salter-Harris type I frac- dren are discussed. tures and 139 were type II fractures. Symptomatic growth dis- crepancy of greater than 1 cm at skeletal maturity occurred in Rajesh A, Basu AK, Vaidhyanath R, Finlay D: Hand 4.4% of the distal radius physeal fractures and 50% of distal fractures: A study of their site and type in childhood. ulnar physeal fractures. Clin Radiol 2001;56:667-669. Jones IE, Williams SM, Dow N, Goulding A: How many Radiographs of 280 children with hand fractures were re- children remain fracture-free during growth?: A longitu- viewed and categorized by site of the injury and age of the pa- dinal study of children and adolescents participating in tient. Distal tuft fractures were the most common in the 0- to the Dunedin Multidisciplinary Health and Development 4-year age group; distal phalanx fractures occurred most fre- Study. Osteoporos Int 2002;13:990-995. quently in the 5- to 8-year age group; fractures of the proximal phalanx of the small finger were most common in the 9- to 12- Results of a longitudinal study of 601 people from New year age group; and fractures of the small finger metacarpal Zealand showed that approximately half (60% girls, 50% occurred most frequently in the 13- to 16-year old age group. boys) of the children in the study did not have a fracture throughout their growth period. More than one fracture oc- Congenital Upper Extremity Malformations curred in 119 children (16% girls, 23% boys). The forearm was the most common site of fracture (24%). Giele H, Giele C, Bover C, et al: The incidence and epi- demiology of congenital upper limb anomalies: A total Ronning R, Ronning I, Gerner T, Engebretsen L: The population study. J Hand Surg [Am] 2001;26:628-634. efficacy of wrist protectors in preventing snowboarding injuries. Am J Sports Med 2001;29:581-585. A homogeneous population study found congenital upper extremity anomalies in approximately 2 per 1,000 live births Results of a randomized, prospective study of 5,029 snow- with nearly 50% of those affected having some other anomaly. boarders in Norway is presented. A significant decrease in in- Failure of separation and duplications were the most common jury rate was found with the use of wrist protectors. Beginners malformations and increased in number with advanced mater- and those using rental equipment were at highest risk for wrist nal age. injury. Goldfarb CA, Klepps SJ, Dailey LA, et al: Functional Wareham K, Johansen A, Stone MD, Saunders J, Jones outcome after centralization for radius dysplasia. S, Lyons RA: Seasonal variation in the incidence of J Hand Surg [Am] 2002;27:118-124. wrist and forearm fractures and its consequences. Injury 2003;34:219-222. This long-term review of patients undergoing centraliza- tion found residual radial angulation of 36°, wrist arc of mo- A longitudinal study from Wales showed a seasonal varia- tion of 31°, and an average ulnar length that was 54% of that tion in the incidence of wrist and forearm fractures in children found in the uninvolved contralateral ulna. Surgery resulted in younger than 15 years of age. The incidence in the three win- improvement in wrist alignment but with less benefit to func- ter months (5.7/1,000 per year) was half the incidence for frac- tional improvement than previously believed. tures the rest of the year (10.7/1,000 per year). The fractures that occurred during the nonwinter months were more severe Greuse M, Coessens BC: Congenital syndactyly: Defat- with 23% of patients with forearm and wrist fractures requir- ting facilitates closure without skin graft. J Hand Surg ing hospitalization during the spring, summer, and fall com- [Am] 2001;26:589-594. American Academy of Orthopaedic Surgeons 727

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 The authors performed syndactyly separation with the use This long-term retrospective review found that most pa- of graft by performing extensive defatting. Skin graft was re- tients with Madelung’s deformity are female (77%), with a quired for complex cases and reoperation was performed in 2 positive family history in 13% of those affected. Despite sur- of 16 patients. gery, almost all patients had limited range of motion. Kemnitz S, De SL: Pre-axial polydactyly: Outcome of Classic Bibliography the surgical treatment. J Pediatr Orthop B 2002;11:79-84. Bayne LG, Klug MS: Long-term review of the surgical This retrospective study of patients who underwent recon- treatment of radial deficiencies. J Hand Surg [Am] 1987; struction of preaxial polydactyly found high levels of patient 12:169-179. satisfaction. Functional outcome was affected by joint stability. Benson LS, Waters PM, Kamil NI, Simmons BP, Upton J Keswani SG, Johnson MP, Adzick NS, et al: In utero III: Camptodactly: Classification and results of nonoper- limb salvage: Fetoscopic release of amniotic bands for ative treatment. J Pediatr Orthop 1994;14:814-819. threatened limb amputation. J Pediatr Surg 2003;38:848- 851. Buck-Gramcko D: Pollicization of the index finger: Method and results in aplasia and hypoplasia of the The use of fetoscopic laser surgery to release constriction thumb. J Bone Joint Surg Am 1971;53:1605-1617. rings at the level of the wrist improved extremity blood flow in utero. Carter PR, Ezaki M: Madelung’s deformity: Surgical correction through the anterior approach. Hand Clin McAdams TR, Moneim MS, Omer GE Jr: Long-term 2000;16:713-721. follow-up of surgical release of the A (1) pulley in child- hood trigger thumb. J Pediatr Orthop 2002;22:41-43. Cole RJ, Manske PR: Classification of ulnar deficiency according to the thumb and first web. J Hand Surg The authors report on the results of long-term follow-up [Am] 1997;22:479-488. on patients undergoing trigger thumb release. Patients with a transverse incision had better appearance. Twenty-three per- Fitoussi F, Mazda K, Frajman JM, Jehanno P, Pennecot cent of these patients had incomplete interphalangeal joint GF: Repair of the flexor pollicus longus tendon in chil- motion, and 17% had metacarpophalangeal hyperextension. dren. J Bone Joint Surg Br 2000;82:1177-1180. Moon WN, Suh SW, Kim IC: Trigger digits in children. Gibbons CL, Woods DA, Pailthorpe C, et al: The man- J Hand Surg [Br] 2001;26:11-12. agement of isolated distal radius fractures in children. J Pediatr Orthop 1994;14:207-210. In this study of more than 7,000 newborn infants, no in- stances of trigger thumb or trigger finger were found. Trigger Horii E, Nakamura R, Sakuma M, Miura T: Duplicated fingers developed earlier in life than trigger thumb and had a thumb bifurcation at the metacarpophalangeal joint lev- higher spontaneous recovery rate. el: Factors affecting surgical outcome. J Hand Surg [Am] 1997;22:671-679. Murase T, Tada K, Yoshida T, et al: Derotational osteot- omy at the shafts of the radius and ulna for congenital Hung L, Cheng JC, Bundoc R, et al: Thumb duplication radioulnar synostosis. J Hand Surg [Am] 2003;28:133- at the metacarpophalangeal joint: Management and a 137. new classification. Clin Orthop 1996;323:31-41. The authors describe a two-level osteotomy with the ra- James MA, McCarroll HR, Manske PR: The spectrum dius osteotomy at the distal third and the ulnar osteotomy at of radial longitudinal deficiency: A modified classifica- the proximal third. Pronation deformity was corrected by tion. J Hand Surg [Am] 1999;24:1145-1155. manual derotation. Mani GV, Hui PW, Cheng JC: Translation of the radius Rayan GM, Frey B: Ulnar polydactyly. Plast Reconstr as a predictor of outcome in distal radial fractures of Surg 2001;107:1449-1454. children. J Bone Joint Surg Br 1993;75:808-811. This study reviews the various types of ulnar polydactyly Manske PR, Halikis MN: Surgical classification of cen- and their treatments. Most patients (71%) had soft-tissue tags tral deficiency according to the thumb web. J Hand Surg that were treated by ligation. African American patients were [Am] 1995;20:687-697. most likely to have soft-tissue duplications only, whereas white patients were more likely to have digits with bony elements. Schmidt-Rohlfing B, Schwobel B, Pauschert R, et al: Manske PR, Rotman MB, Dailey LA: Long-term func- Madelung deformity: Clinical features, therapy and re- tional results after pollicization for the congenitally defi- sults. J Pediatr Orthop B 2001;10:344-348. cient thumb. J Hand Surg [Am] 1992;17:1064-1072. 728 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics McCarroll HR: Congenital anomalies: A 25 year over- Proctor MT, Moore DJ, Paterson JM: Redisplacement view. J Hand Surg [Am] 2000;25:1007-1037. after manipulation of distal radial fractures in children. J Bone Joint Surg Br 1993;75:453-454. McCarty E, Mencio G, Green N: Anaesthesia and anal- gesia for the ambulatory management of fractures in Shoemaker S, Comstock C, Mubarak S, et al: Intramed- children. J Am Acad Orthop Surg 1999;7:81-91. ullary kirschner wire fixation of open or unstable fore- arm fractures in children. J Pediatr Orthop 1999;19:329- Mintzer CM, Waters PM: Surgical treatment of pediatric 337. scaphoid nonunions of the scaphoid. J Pediatr Orthop 1999;19:329-337. Smith PJ, Grobbelaar AO: Camptodactyly: A unifying theory and approach to surgical treatment. J Hand Surg Johnson KJ, Haigh SF, Symonds KE: MRI in the man- [Am] 1998;23:14-19. agement of scaphoid fractures in skeletally immature patients. Pediatr Radiol 2000;30:685-688. Vransky P, Bourdelat D, Al Faour A: Flexible intramed- ullary pinning technique in the treatment of pediatric O’Connell SJ, Moore MM, Strickland JW, et al: Results fractures. J Pediatr Orthop 2000;20:23-27. of zone I and zone II flexor tendon repairs in children. J Hand Surg [Am] 1994;19:48-52. Waters PM, Kolettis GJ, Schwend R: Acute median neu- ropathy following physeal fractures of the distal radius. Ogino T, Kato H: Clinical and experimental studies on J Pediatr Orthop 1994;14:173-177. teratogenic mechanisms of congenital absence of digits in longitudinal deficiencies. Cong Anom 1993;33:187- 196. American Academy of Orthopaedic Surgeons 729



Chapter 62 Hip, Pelvis, and Femur: Pediatrics Keith R. Gabriel, MD Eric J. Wall, MD Developmental Dysplasia of the Hip decreased or abnormal fetal movement is a feature, such as arthrogryposis and spina bifida. Treatment of these Incidence hips depends as much on the nature of the overall disor- der as on the dislocated hip itself. Although ligamentous Most newborn screening studies, usually based on physi- laxity has been suggested as a risk factor, DDH is not cal examination techniques, suggest that some degree of especially associated with genetic conditions such as the hip instability can be detected in 1 in 100 to 1 in 250 ba- Marfan, Ehlers-Danlos, or Down syndromes, in which bies. Actual dislocated or dislocatable hips are much less generalized joint laxity is a prominent feature. frequent, being found in 1 to 1.5 of 1,000 live births. Late presentation of developmental dysplasia of the hip In infants who are otherwise normal, the most im- (DDH) is found in approximately 4 per 10,000 children. portant risk factors for DDH are female gender, family history, and breech positioning. In addition to routine Etiology screening, some types of imaging studies are often rec- ommended for these infants. There is no single cause of DDH. The basic structures of the human hip joint are well formed by the 11th fetal Diagnosis week. Subsequent development of the hip requires a continuous synergistic molding and growth of the imma- Physical Examination ture femoral head and the acetabulum. Any process or For newborns and neonates, the mainstay of physical di- event that interrupts this interaction can result in struc- agnosis has been the palpable sensation of the hip slid- tural abnormality and instability. Those hips that dislo- ing out of or into the acetabulum. Barlow’s test is a pro- cate early during the course of fetal development will vocative maneuver in which the examiner attempts to have extreme anatomic abnormalities, and are called subluxate or dislocate the hip by pressing gently down- teratologic dislocations. ward on the flexed, adducted thigh. Ortolani’s test is a reduction maneuver performed by abducting the flexed The risk of DDH has been found to be 34% in iden- hip while lifting gently forward under the greater tro- tical twins, but only 3% in fraternal twins. The frequency chanter. Palpable luxation or reduction of the joint con- in siblings is approximately 6% to 7%. If one parent stitutes a positive test. Most high-pitched “clicks” are and one sibling have DDH, the risk to subsequent in- transmitted from the greater trochanteric or knee areas, fants rises to 36%. The genetic influence may also be and are inconsequential. seen in comparisons of different ethnic groups, with high rates among Lappish and very low rates among Between 3 and 6 months of age, the soft tissues Bantus. tighten sufficiently that a reduced hip does not dislocate with Barlow’s test and a dislocated hip cannot be re- Infants who have been in the breech position during duced with Ortolani’s test. Hip abduction in flexion will the third trimester and/or perinatally have a higher risk be limited on the affected side, and the thigh will be of DDH, as high as 20% for those in the frank breech foreshortened. In unilateral cases, the shortening is con- position. An increased incidence is also found with con- veniently demonstrated by the Galeazzi (or Allis) test, ditions typically associated with intrauterine crowding, in which the infant is positioned supine with the hips such as oligohydramnios, congenital recurvatum or dis- and knees flexed so that the relative height of the knees location of the knee, and congenital muscular torticollis. can be assessed. Postnatally, a high incidence of DDH is found in those societies where infants are customarily strapped or After these children begin to stand, a flexion con- swaddled with the thighs adducted. tracture usually develops at the affected hip. Increased lumbar lordosis and pelvic obliquity are seen. The pa- DDH is associated with certain neuromuscular con- ditions and genetic syndromes, especially those in which American Academy of Orthopaedic Surgeons 731

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 Figure 1 Standard reference lines and angles used to interpret pelvic radiographs in centage of coverage of the femoral head can also be as- DDH. The femoral ossific nucleus normally is located in the lower, inner quadrant sessed. In dynamic ultrasound assessment, the position formed by the intersection of Hilgenreiner’s (horizontal) and Perkins’ (vertical) lines. of the femoral head with respect to the posterior bony Shenton’s line is a continuous arc along the inferior border of the femoral neck and wall of the acetabulum is monitored as the hip is superior margin of the obturator foramen, which is disrupted when the femoral head is stressed with a modified Barlow’s test. dislocated. The acetabular index measures the inclination of the acetabulum. Normal values for a newborn are less than 30° (average 27.5°). (Reproduced with permission The use of ultrasound in the routine screening of all from Guille J, Pizzutillo P, MacEwen G: Developmental dysplasia of the hip from birth newborns is neither cost effective nor practical. The pro- to six months. J Am Acad Orthop Surg 2000;8:232-242.) cedure is so sensitive that routine use has resulted in overdiagnosis, above the expected incidence of DDH. tients walk with gluteus medius insufficiency because of The presence or severity of ultrasound abnormalities in the high position of the greater trochanter. In unilateral infants who have otherwise normal hip examinations cases, the limb-length inequality may either contribute does not correlate with ultimate outcome. Routine ul- to a limp, or may be compensated by toe-walking on the trasound screening of newborns has not been shown to affected side. Once again, limitation of hip abduction in reduce the prevalence of late-diagnosed dysplasia. flexion is a useful finding in all age groups. Ultrasound evaluation at 3 to 4 weeks after birth is Lesser degrees of dysplasia may include a function- useful as an adjunct in those patients having equivocal ally stable but anatomically insufficient hip. These situa- findings on initial nursery examination, and for those in tions are ordinarily clinically silent in younger children. high-risk groups. Ultrasound can be used to check hip The abnormality may be discovered incidentally, but stability and document reduction during treatment or at more often presents in later life as hip pain or degenera- the completion of treatment. The greatest advantage is tive arthritis. that serial examinations can be done without exposing the infant to ionizing radiation. Imaging: Ultrasound, Radiography, CT, MRI, and Arthrography Femoral head ossification usually begins by age 6 Ultrasound allows visualization of cartilaginous and months, and plain radiographs then become the primary soft-tissue structures before femoral head ossification. imaging modality for DDH. Radiography also remains The static acetabular morphology, as described by Graf, useful to evaluate the distorted anatomy of teratologic is based on two angles measured in the coronal plane. A dislocations. Traditionally, several lines are projected reference line common to both angles is first established across the visible ossified portions of the pelvis and along the lateral wall of the ilium superior to the ace- proximal femur to assist in interpretation of the plain tabulum. The α angle is subtended by this iliac line and films. Hilgenreiner’s, Perkins’, and Shenton’s lines are a line tangential to the bony roof of the acetabulum. commonly used, as illustrated in Figure 1, to determine The β angle is subtended by the iliac line and a line tan- the alignment of the proximal femur to the pelvis. The gential through the cartilaginous labrum. In general, a acetabular index provides information about the con- normal, mature infant hip should have an α angle of tour of the acetabulum itself. greater than 60° and a β angle of less than 55°. The per- CT, MRI, and arthrography do not play a significant role in the primary diagnosis of DDH. Each modality has specific uses in treatment. CT is currently the study of choice for assessing hip reduction in a spica cast after closed or open treatment. Limited use of CT directly through the acetabulum requires a minimum of radia- tion exposure. Sedation is seldom needed, as the patient is immobilized in the cast and spiral acquisition tech- niques for CT have decreased the time required for these studies. A method of hip reduction and spica cast application with the infant in the MRI scanner has been investigated, but is not yet feasible in most areas. Both CT and MRI data can be presented as three- dimensional images, and software is available to manip- ulate these images when planning various osteotomies. Arthrography is unparalleled for showing dynamically the soft-tissue impediments to reduction, and is useful to confirm position and stability in closed or open pro- cedures. However, it is an invasive study that requires sedation or anesthesia. 732 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics Screening orthoses. It is critical that forced or extreme abduction be avoided. Regardless of the splint chosen, concentric re- All babies should be screened for hip dysplasia. How- duction must be verified within 2 to 3 weeks of initiation ever, the scope, timing, and methodology of neonatal of treatment. If reduction is not confirmed within that pe- screening for DDH are areas of current controversy. riod, the splinting device should be abandoned and an- Hips dislocated at birth should be treated, with the ex- other method of treatment chosen. When successful, the ception of certain teratologic situations. However, 75% abduction splint should be worn on a full-time basis until to 90% of hips found to be subluxatable at birth will the hip is stable, and part-time wear is recommended until spontaneously stabilize within a few weeks. A reason- acetabular remodeling is confirmed. able protocol is to reexamine all hips having question- able nursery examinations, and infants with recognized Closed Reduction risk factors for dysplasia, at 2 to 3 weeks after birth. Most infants older than age 6 months, those whose hips Hips with persistent laxity at that point should be are not reducible with a simple Ortolani maneuver, and treated. Ultrasound may be used at week 3 or 4 as an those in whom splinting in abduction fails will need a adjunct in questionable or high-risk situations. Hips that more formal closed or open reduction of the hip. Closed are stable at the 3-week examination but show dysplas- methods are preferred up to about age 2 years, but the tic anatomy on ultrasound should be reassessed in 2 to 3 reduction must be obtained and maintained without ex- months. If the dysplasia persists, treatment is indicated. cessive force. Forcible maneuvers and forced rigid im- mobilization carry a high risk of ischemic necrosis. Treatment The use of traction before closed reduction of the The fundamental goals of treatment are the same re- hip has become less common. The goal of traction is to gardless of patient age. Concentric reduction should be gently and gradually stretch the soft tissues surrounding obtained and maintained, with a minimum of risk to the the hip, so that closed reduction can be achieved with- blood supply of the capital femoral epiphysis. The later out undue force. However, comparison studies have DDH is diagnosed, more complex interventions are shown that adductor tenotomy and immobilization in needed and the risk of complications increases. the human position (hips flexed 100°, abducted 45° and neutrally rotated) can achieve comparably low rates of Abduction Splinting ischemic necrosis. Infants whose hips are subluxatable, reduced but dislo- Closed reduction should be done under general an- catable, or dislocated but reducible can usually be esthesia, with an arthrogram used to verify positioning. treated by splinting the hips in flexion and gentle abduc- A concentric reduction must be obtained, with no more tion. Most of these infants will be younger than 6 than 5 mm of contrast pooling medially between the months of age, although occasionally the hips of a femoral head and the acetabulum, and with no soft- slightly older infant remain Ortolani positive. Some- tissue interposition. With the hips flexed, a safe zone of times abduction splinting is used to achieve reduction of abduction should be assessed: an arc of stable position- a dislocated hip in infancy. This procedure must be done ing between redislocation (toward adduction) and the with care to avoid forced positioning, and the attempt limit of comfortable, unforced abduction. If the safe should be abandoned if not successful within 2 to 3 zone is unacceptably narrow, an adjunctive procedure weeks. such as percutaneous adductor tenotomy may be indi- cated to release soft-tissue tension and increase the The most popular abduction splint used in the range of available abduction. The infant is then immobi- United States is the Pavlik harness, although it has some lized in a spica cast in the human position (hip flexion limitations and potential problems. It is an active device, of about 100° and abduction of about 45°) for 3 to 4 in that normal muscle function is required; it is not ef- months. Part-time abduction bracing should be contin- fective in patients with paralysis or spasticity. If the an- ued until acetabular remodeling is complete. It is not terior straps hold the hips hyperflexed, femoral nerve unusual for infants treated by closed reduction to palsy or inferior hip dislocation can occur. The persis- achieve stable hips, but to require a secondary acetabu- tent use of the Pavlik harness with the hip in a posteri- lar or femoral procedure to correct residual deformity. orly subluxated position will result in a failure of devel- opment of the posterior wall of the acetabulum, Open Reduction sometimes called Pavlik disease. Prolonged prone posi- Failure to obtain a concentric closed reduction of the tioning of the infant wearing the harness should be hip is an indication for open reduction in all age groups. avoided, because the combined effect of the harness and Any hip in which extreme positioning is required to the weight of the torso forces the hips into maximal ab- maintain reduction should also be treated by open re- duction, increasing the risk of ischemic necrosis. duction. In general, children older than 2 years of age will require open reduction. Good results are also obtained with other abduction splints such as the von Rosen splint or various Plastazote American Academy of Orthopaedic Surgeons 733

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 Figure 2 Redirectional osteotomies. A, Single innominate (Salter). B, Triple in- nominate (Steel). C, Bernese pericapsular (Ganz). (Reproduced with permission from Gillingham B, Sanches A, Wenger D: Pelvic osteotomies for the treatment of hip dys- plasia in children and young adults. J Am Acad Orthop Surg 1999;7:325-337.) Anteromedial and medial approaches have most of- Capsulorrhaphy and pelvic osteotomy can be performed ten been recommended for younger children (2 years through this approach. Postoperative immobilization is old or younger). All approaches include division of the in the functional position, with approximately 15° of origin of the adductor longus. One anteromedial varia- flexion, 15° of abduction, and neutral rotation. tion then proceeds between the pectineus medially and the femoral neurovascular bundle laterally. Division of Femoral shortening at the time of open reduction the psoas tendon allows direct access to the anterome- has taken the place of preoperative traction for reduc- dial hip capsule. With exception of an inverted labrum, ing soft-tissue tension around the hip. This procedure is obstacles to reduction can be easily visualized and re- virtually always necessary for children older than age 2 moved. However, there is no opportunity to perform years, but should be considered in each patient. A sepa- capsulorrhaphy or osteotomy through this exposure. A rate lateral approach is necessary. The hip is reduced, a potential disadvantage is that the medial femoral cir- subtrochanteric osteotomy of the femur is performed, cumflex artery is in the field of deep dissection, which and the soft tissues are allowed to retract. The resulting some believe increases the risk of ischemic necrosis. overlapped segment of proximal femur is resected, and the femur is internally fixed with a plate and screws. Alternatively, after division of the origin of the ad- Varus and rotation can be adjusted through this osteot- ductor brevis, the pectineus may be retracted laterally omy as needed for hip stability. It is important to avoid and the deep dissection can then proceed either anterior excessive retroversion of the femur, especially if con- or posterior to the adductor brevis. These two variations comitant pelvic osteotomy is done, as this increases the are conceptually less direct than the anteromedial ap- risk of posterior redislocation of the hip. proach, and are not well suited for high dislocations. Other indications and limitations are similar. In older children, the acetabulum will be more se- verely dysplastic. Anterolateral coverage will be insuffi- The most commonly used anterior approach for open cient. It is frequently necessary to consider concomitant hip reduction is that of Smith-Peterson, generally modi- pelvic osteotomy at the time of open reduction to en- fied by using a bikini incision parallel to the groin flexion sure stability of the hip. The Salter innominate osteot- crease. Dissection is deepened between the tensor fascia omy will redirect the acetabulum to restore approxi- femoris and the sartorius, mobilizing the origins of the ten- mately 25° of lateral coverage and 10° of anterior sor fascia femoris from the iliac wing. Division of the or- coverage (Figure 2). As indicated previously, combined igins of the rectus femoris then gives access to the ante- pelvic and femoral osteotomy must be done carefully to rior, superior, and lateral hip capsule. A separate avoid posterior instability of the joint. tenotomy, either percutaneous or open, of the adductor longus is recommended. All of the impediments to reduc- Upper Age Limits tion can be addressed via this approach. If an inverted la- Beyond a certain age, surgical treatment is unlikely to brum is identified, it can be released by making several produce a stable, mobile, pain-free joint for the long radial cuts in the tight area. The labrum should not be ex- term. Despite obvious gait abnormalities, bilateral pain- cised. free dislocations probably should not be reduced after age 6 or 7 years. Unilateral dislocations are generally This approach is suitable for all age groups. The dis- section preserves the medial femoral circumflex vessels. 734 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics more problematic, because of limb-length inequality and pelvic obliquity. Therefore, reduction of unilateral dislocations is considered until adolescence. Complications Figure 3 Reshaping osteotomy of Dega, which preserves the sciatic notch and a variable portion of the inner table of the ileum. (Reproduced with permission from Redislocation Vitale MG, Skaggs DL: Developmental dysplasia of the hip from six months to four Redislocation after closed reduction can usually be years of age. J Am Acad Orthop Surg 2001;9:401-411.) treated by repeat closed reduction or open reduction with no deleterious effect on long-term outcome. Redislocation following open reduction is usually attributable to some flaw in the initial procedure. Inadequate inferior capsular release, inadequate capsulorrhaphy, and posterior instabil- ity from combined pelvic and femoral osteotomies are common errors. Repeat surgery is almost always neces- sary to correct the problem, and results are generally worse than with primary open reduction. Ischemic Necrosis osteotomies that reorient the acetabulum without chang- Ischemic necrosis of the femoral head is seen with all ing its shape have been described, and the choice, in forms of treatment. Causes include extrinsic compres- large measure, depends on patient age (Figure 2). The sion of the vasculature supplying the capital femoral ep- single innominate osteotomy (Salter) depends on flexi- iphysis, and excessive direct pressure on the cartilagi- bility of the symphysis pubis to allow sufficient rotation nous head. Excessive or forceful abduction, previous of the acetabular segment. In older children this flexibil- failed closed treatment, and repeat surgery are associ- ity is lost, and triple osteotomy (Steel or Tonnis) is pre- ated with increased rates of ischemic necrosis. The ques- ferred so that the acetabular segment of the pelvis can tion of whether ossification of the femoral head before be rotated without violating the triradiate growth poten- treatment might affect ischemic necrosis rates is not tial. After closure of the triradiate cartilage, the periace- fully resolved. tabular osteotomy (Bernese) is appropriate. The diagnosis of ischemic necrosis is based on radio- If the intrinsic shape of the acetabulum must be al- graphic findings that include failure of appearance or tered to improve congruence, reshaping osteotomies growth of the ossific nucleus 1 year after reduction, such as the Pemberton or the Dega should be consid- broadening of the femoral neck 1 year after reduction, ered. These osteotomies require an open triradiate carti- increased density and then fragmentation of the ossified lage to allow hinging through the acetabulum itself. The femoral head, or residual deformity of the femoral head inner and outer tables of the ileum are divided in the and neck after ossification. Classifications of ischemic Pemberton, whereas only the outer table is cut in the necrosis separate partial involvement from complete ne- Dega (Figure 3). Both proceed into the posterior limb crosis, which causes progressive femoral head and neck of the triradiate, and preserve the posterior wall of the deformity. Treatment depends on degree of severity. ischium at the sciatic notch. Late Dysplasia Salvage osteotomies increase the surface area avail- able for weight bearing, and depend on fibrocartilagi- In a growing child, the mechanically stable hip that is nous metaplasia of the interposed hip capsule to form reduced but dysplastic may be monitored with serial ra- an articulating surface. The Chiari innominate osteot- diographs. Failure of improvement with growth is an in- omy and various shelf acetabular augmentations are dication for intervention, as is symptomatic dysplasia in available (Figure 4). the adolescent. Analysis of the late dysplastic hip is fa- cilitated by CT or MRI studies with three-dimensional Developmental Coxa Vara reconstruction. Femoral, pelvic, or concomitant osteot- omy may be required, according to the location of the Developmental coxa vara has an estimated incidence of major deformity. Pelvic osteotomies are grouped into 1 in 25,000 live births. Males and females are affected reconstructive and salvage types. with equal frequency, there is no predilection for the right or left side, and the condition is bilateral in ap- If it is possible to concentrically and congruently re- proximately 50% of patients. duce a dysplastic hip, a reconstructive osteotomy may be indicated to improve coverage of the femoral head with The underlying defect of this condition is unknown. the native articular cartilage of the acetabulum. Several The most widely accepted theory regarding the progres- American Academy of Orthopaedic Surgeons 735

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 Figure 5 Hilgenreiner’s physeal angle is created by a line through the triradiate carti- lage and its intersection with a line through the physis. The normal angle is about 25°. (Reproduced with permission from Beals RK: Coxa vara in childhood: Evaluation and management. J Am Acad Orthop Surg 1998;6:93-99.) Figure 4 Salvage procedures. A, Chiari. B, Shelf slotted acetabular augmentation. more vertical) is associated with progression of the coxa (Reproduced with permission from Gillingham B, Sanchez A, Wenger D: Pelvic osteoto- vara, stress fracture and nonunion of the femoral neck, mies for the treatment of hip dysplasia in children and young adults. J Am Acad and early degenerative arthritis of the hip. The overall Orthop Surg 1999;7:325-337.) radiographic appearance of the hip is similar in some skeletal dysplasias, so screening radiographs of other ar- sive deformity is that there exists an unspecified primary eas should be obtained for every patient on initial pre- ossification defect in the inferior femoral neck. Physio- sentation. logic stresses of weight bearing cause fatigue failure of the local dystrophic bone, resulting in the progressive varus Nonsurgical treatments have been unsuccessful. Sur- displacement. MRI and some biopsy specimens support gical derotational valgus-producing osteotomy of the this theory. proximal femur is indicated when Hilgenreiner’s phy- seal angle is greater than 60°, the physeal angle is Patients usually have a progressive but painless gait greater than 45° and the deformity is progressing, the abnormality during early childhood. The coxa vara cre- femoral neck-shaft angle is less than 90°, or the patient ates a high-riding position of the greater trochanter (de- develops a significant Trendelenburg gait. Surgical goals crease or reversal of the articulotrochanteric distance) include overcorrection of the femoral neck-shaft angle and therefore the hip abductors are functionally weak- to about 160°, restoration of Hilgenreiner’s angle to ened. The children walk with a waddling, Trendelenburg about 25°, and normalization of femoral rotation. Sup- pattern. Those with unilateral involvement have an ad- plemental bone grafting of the inferior femoral neck de- ditional component of limb-length inequality, whereas fect at the time of corrective osteotomy is not necessary. those with bilateral coxa vara have increased lumbar There are differing opinions regarding the best patient lordosis. age for surgery. In general, corrective osteotomy should be performed as soon as the criteria for intervention are The high-riding greater trochanter is prominent on apparent. physical examination. Hip range of motion is restricted in all planes. The loss of abduction is a direct manifesta- If adequate correction into valgus has been tion of the coxa vara. Loss of internal rotation is attrib- achieved, the triangular defect in the inferior femoral uted to a progressive loss of femoral anteversion as the neck closes by 6 months postoperatively. Premature clo- femoral neck displaces. A hip flexion contracture is of- sure of the proximal femoral physis occurs by 24 months ten present. The lower extremity length discrepancy in in most surgically treated hips, even though the physeal patients with unilateral deformity is generally mild. plate is not violated during surgery. The patient must therefore be monitored for subsequent limb-length ine- The radiographic indicator of developmental coxa quality. If premature closure of the proximal femoral vara is a triangular metaphyseal fragment in the inferior physis is recognized, apophyseodesis or advancement of femoral neck, delineated by an inverted Y-shaped radio- the greater trochanter should be considered. Recur- lucency. There is a decrease in the femoral neck-shaft rence of varus is unusual if adequate valgus has been angle, sometimes to values below 90°. The position of achieved at surgery. the physeal plate is measured by Hilgenreiner’s physeal angle, determined on the AP view as the angle between Slipped Capital Femoral Epiphysis Hilgenreiner’s line and the plane of the proximal femo- ral physis. A normal Hilgenreiner’s angle should be less Slipped capital femoral epiphysis (SCFE) is one of the than 25° (Figure 5). Spontaneous healing may occur most common hip disorders in the pubertal child. The when Hilgenreiner’s angle remains less than 45°. A diagnosis can be delayed because 15% of patients have Hilgenreiner’s angle of greater than 60° (increasingly 736 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics knee pain instead of hip pain, and those patients with ical limp. When the patient bears weight on the painful hip pain are often initially believed to have a pulled lower extremity, they will lean over that extremity dur- groin muscle. Historically, the condition and its treat- ing the stance phase of gait. This unusual limp pattern ment have been fraught with frequent complications helps localize the cause of pain to the hip. Conversely, such as chondrolysis, osteonecrosis, slip progression, patients tend to lean away from the involved side if the intra-articular pin penetration, hip stiffness, and degen- pain emanates from below the hip. Patients with SCFE erative arthritis. Currently, with early diagnosis and sin- tend to externally rotate their lower extremity while gle cannulated screw fixation, the outcome is usually ex- walking. cellent in stable SCFE with minimal or moderate displacement. Osteonecrosis, which is usually seen only The hallmark of the clinical examination is that as in unstable SCFE, and severe slip displacement can lead the examiner flexes the hip of a patient with SCFE, the to early hip degeneration. patient’s leg will externally rotate obligatorily. There is usually complete loss of internal rotation, and any at- Etiology tempt at testing hip internal rotation causes pain. The diagnosis of SCFE is confirmed with AP and frog-lateral The etiology of SCFE is unknown, but it is probably a hip radiographs. The earliest radiographic sign of SCFE mechanical problem of increased sheer stress across a can be growth plate widening or lucency (termed epi- capital femoral growth plate weakened either by rapid physiolysis) and patients with chronic slips may develop growth, or by a condition such as pelvic radiation, hy- a radiodense blush sign on the metaphyseal side of the pothyroidism, renal failure, or growth hormone treat- capital femoral growth plate. On the AP radiograph of a ment. Most children with SCFE are above the 95th per- normal hip, a line drawn up along the superior border of centile for weight and are obese; these factors place the femoral neck (Klein’s line) should project over the increased stress across the growth plate. Growth plates lateral edge of the femoral head. In a child with SCFE show physiologic weakness during periods of rapid the femoral head may not project over this line (Figure growth such as the pubertal growth spurt. Endocrine 6). Patients who have the earliest stage of SCFE may consultation or endocrine screening laboratories are not have normal radiographs (preslip). MRI can help diag- indicated unless the patient has atypical endocrine find- nose a preslip condition by showing metaphyseal high ings. Children with SCFE who are younger than 10 signal next to the growth plate and growth plate years of age or 16 years and older, or whose weight is widening. below the 50th percentile have a high incidence of atyp- ical SCFE and may require further workup. No specific Classification genetic component has been identified with SCFE. In the most useful classification for SCFE, the condition Epidemiology is either stable or unstable. Stable slips are defined by the mode of clinical presentation. If a patient can walk The prevalence of SCFE in the United States ranges be- into the examiner’s office, with or without crutches, they tween 2 to 10 cases per 100,000 children. Male children have a stable slip. With an unstable slip, the patient has outnumber females with the disease by a 3:2 ratio, and difficulty with ambulation and usually presents on a gur- the mean age for diagnosis is about 13.5 years for boys ney or in a wheelchair. This classification helps with and 12 years for girls, which corresponds with the age at prognosis in that the most feared complication of SCFE, which the adolescent growth spurt occurs. Fifty percent osteonecrosis of the femoral head, is usually only seen of children with SCFE are above the 95th percentile for with unstable slips. Increased SCFE displacement and weight according to age. There is an increased incidence increased angle of the slip relative to normal anatomy of SCFE during the summer and fall months and it re- correlate with less favorable outcomes than mild slips. portedly is bilateral in 17% to 50% of patients. Approx- imately half the children who have bilateral hip involve- Treatment ment are identified at the time of initial presentation. Therefore, both hips should be examined and bilateral The most popular treatment of SCFE is single screw fix- radiographs obtained for every patient with a unilateral ation across the capital femoral growth plate performed presentation of SCFE. in situ (without reduction) in stable slips. Although sin- gle screw fixation seems to be the gold standard for Diagnosis most slips, recent articles have shown slip progression after single screw fixation. Single screw fixation using Studies show that approximately 85% of children have a modern fluoroscopic techniques that avoid persistent history of hip or proximal thigh pain and 15% have only joint penetration have virtually eliminated the risk of knee pain. Therefore, in any adolescent with knee pain, chondrolysis (cartilage deterioration and hip stiffness) range of motion should be assessed on the ipsilateral that was previously a common complication of SCFE hip. The patient with SCFE will usually have a paradox- pinning. The success and simplicity of single cannulated American Academy of Orthopaedic Surgeons 737

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 Figure 6 AP radiograph of the pelvis shows that on the left hip the lateral epiphysis drolysis. Single pin fixation is also recommended for un- does not cross a line drawn along the superior edge of femoral neck (Klein’s line). This stable slips, although some authors have stated a need is consistent with a subtle SCFE on the left hip. The right femoral epiphysis does cross for two screws. Because unstable SCFE has a high rate this line and is normal. of osteonecrosis, some authors recommend early reduc- tion and arthrotomy to reduce possible compression on screw fixation has decreased the popularity of alterna- the extracapsular epiphyseal vessels. Traditionally, re- tive treatments of stable SCFE such as bone peg epi- duction was believed to increase the risk of osteonecro- physiodesis, hip spica casting, and femoral neck sis, hence the emphasis on in situ fixation. Frequently, osteotomy. spontaneous reduction occurs when patients are placed on the fracture table because of the weight of the proxi- Technique of Cannulated Screw Fixation mal thigh and femur. One recent study reported an in- creased risk of osteonecrosis associated with reduction; Patients with SCFE are usually pinned on a fracture ta- however, another recent study found no such increase ble that allows clear AP and lateral views of the hip. Be- and concluded that spontaneous and gentle reduction is cause obesity can impair visualization of the hip with safe. Prophylactic pinning of the unslipped opposite hip, SCFE, it is imperative to confirm visualization of the for which the risk of future slip is 25% or less, is also hip joint surface on the AP and lateral radiographic controversial. After one hip has slipped, patients and views before commencing the procedure. A radiolucent their families are much more attuned to the condition standard operating room table can also be used instead and will seek treatment early when pain or limp develop of the fracture table by rotating the hip between AP and in the opposite hip. Most pediatric orthopaedists choose frog-lateral views; however, this is indicated only for sta- not to perform prophylactic pinning, but recommend ble hips. After the patient is on the table, AP and lateral that patients return to the office at the first sign of pain guidelines can be drawn on the skin surface to mark the or limp in the opposite hip. Because up to 57% of oppo- entry position. Large cannulated screws are the most site hip slips are asymptomatic and current fixation popular for fixation, which is usually performed in situ. methods have low complication rates, recent decision An adequate number of screw threads should be placed analysis reviews tend to support prophylactic pinning of into the center of the epiphysis to facilitate a stable fixa- the unslipped opposite hip. tion without joint penetration. After fixation is achieved, the hip is rotated under live fluoroscopy to as- Legg-Calvé-Perthes Disease certain that the pin is not penetrating the hip joint. Pins that are not placed centrally in the femoral head can in- Idiopathic osteonecrosis of the femoral head in children advertently penetrate the joint despite two orthogonal is termed Legg-Calvé-Perthes disease. Its specific cause radiographic views showing no joint penetration. Post- is unknown, but it likely involves a temporary interrup- operatively, patients with stable slips are allowed to bear tion of the blood supply to some portion of the femoral weight as tolerated or limited weight bearing is insti- head that can extend to the adjacent capital femoral tuted for 6 to 8 weeks. growth plate and the metaphysis. The condition tends to run its initial course over a period of 3 to 5 years. In the Controversies short term most patients recover good hip function; however, long-term studies show that by the fifth or Although a few recent studies have shown progressive sixth decade of life approximately 50% of patients with slippage after single screw fixation, the procedure re- prior Legg-Calvé-Perthes disease will develop degenera- mains the current gold standard because it provides the tive arthritis of the hip. Children who experience onset least risk of inadvertent hip joint penetration and chon- of this disease before the age of 6 years, and those who have healing with good hip joint congruence at maturity have the best long-term results. The main goals of treat- ment in Legg-Calvé-Perthes disease are to keep the femoral head contained within the acetabulum and to maintain motion. Treatment can range from observation to physical therapy, casting, and femoral or pelvic os- teotomy. However, the effect of treatment at altering the natural history of Legg-Calvé-Perthes disease re- mains controversial. Epidemiology Legg-Calvé-Perthes disease most commonly occurs in children age 4 to 10 years, but it has been described in 738 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics children age 2 years to teens. It is distinguished from chanter. This four-stage process typically evolves over adult osteonecrosis of the hip primarily because of its 3 to 5 years and tends to proceed more quickly in much better healing and revascularization potential. The younger children than in older children. male to female ratio of occurrence is 5:1. The condition tends to be bilateral in about 10% of children; however, Clinical Presentation it usually does not present at the same time in both hips. The differential diagnosis for simultaneous bilateral hip The typical child with Legg-Calvé-Perthes disease has a osteonecrosis includes Meyer’s dysplasia, spondyloepi- painless limp. The patient may report intermittent hip, physeal dysplasia, multiple epiphyseal dysplasia, sickle thigh, or even knee pain that is typically not severe and cell disease, Gaucher’s disease, and hypothyroidism. does not necessitate use of a crutch. The patient may have a Trendelenburg gait in which body weight is Etiology shifted over the affected hip during the stance phase of gait. This gait pattern (shifting weight away from the af- The etiology of Legg-Calvé-Perthes disease is unknown. fected side during the stance phase of gait) helps to Thrombosis caused by abnormalities in the clotting cas- identify the hip as the source of the patient’s pain. On cade have been recently investigated as the primary eti- clinical examination, the patient usually exhibits joint ology with an initial study showing that approximately stiffness that is most apparent with loss of hip internal 75% of children with this disease have abnormal clot- rotation and hip abduction. Limb-length discrepancy ting factors. Although the rate of clotting factor abnor- and leg muscle atrophy are late findings that can occur malities is small, more recent studies have not validated in patients with more severe hip involvement. On clini- the high rate of inherited thrombosis and thrombophilia cal presentation, the differential diagnosis will include in patients or animals with Legg-Calvé-Perthes disease. septic arthritis, transient synovitis, proximal femoral os- Animal models have shown that multiple episodes of in- teomyelitis, SCFE, and hip dysplasia. Infectious etiolo- farction are necessary to create changes that simulate gies can usually be ruled out through the clinical history the human Legg-Calvé-Perthes disease. As a group, chil- and laboratory studies including erythrocyte sedimenta- dren with this disease tend to be of shorter stature, have tion rate and C-reactive protein levels. DDH and SCFE a delay in bone maturation of approximately 2 years, are usually identified on the radiographs. Transient syn- have a high rate of attention deficit disorder, and have ovitis of the hip usually improves with anti- high rates of exposure to secondhand smoke. However, inflammatory medications within 1 week and is typically no systemic causes have been identified in children with completely resolved within 4 weeks of presentation, ver- Legg-Calvé-Perthes disease. Approximately 2% of chil- sus the longer time course of Legg-Calvé-Perthes dis- dren with transient synovitis of the hip will develop ease. Legg-Calvé-Perthes disease; however this scenario prob- ably results from an initial misdiagnosis and is not a Radiographic Findings cause of the disease. The earliest radiographic finding in Legg-Calvé-Perthes Stages/Pathogenesis disease is an apparent joint space widening caused by failure of the involved femoral ossific nucleus to grow The stages of Legg-Calvé-Perthes disease are based on after the ischemic event. radiographs. During the initial stage the infarction oc- curs, and radiographs may remain occult for the first 3 to Irregularity and increased density of the femoral head 6 months after this initial ischemic event. Most patients ossification center are also early findings. A subchondral present to a physician after radiographic alterations in lucent line (crescent sign) can appear in the femoral head, the femoral head have been noted. In the fragmentation and forms the basis for the Salter-Thompson classification stage, the femoral head appears to fragment or dissolve, system. A crescent sign involving less than half the fem- either partially or totally. This indicator typically occurs oral head is class A, and if it involves more than half the during revascularization as the infarcted bone is re- femoral head it is class B. The extent of fragmentation of sorbed, leaving behind a lucent zone in the femoral head. the ossific nucleus forms the basis of the Catterall and The third phase, termed reossification, occurs when new Herring lateral pillar classifications. In the Catterall clas- bone appears. In the healing stage the femoral head sification stages 1 and 2, fragmentation involves less than reossifies back to normal bone density; however, residual half the femoral head, and in stages 3 and 4 it involves femoral head and neck deformity including shortening more than half the femoral head. The Herring lateral pil- (coxa breva), widening (coxa magna), and flattening may lar classification is based on an AP hip radiograph ob- exist. tained approximately at the start of the fragmentation phase (Figure 7). Only the lateral third of the ossific nu- If the capital femoral growth plate is involved in the cleus is evaluated on this view. A lateral pillar that main- process, there can be tilting of the femoral neck (coxa tains its full height is classified as group A. A lateral pillar valga) and relative overgrowth of the greater tro- that partially collapses but maintains greater than 50% of American Academy of Orthopaedic Surgeons 739

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 with one obtained during maximum hip abduction. The patient’s knees should be pointed forward during film- ing. Failure of the lateral corner of the femoral head to slip under the edge of the acetabulum in the maximum abduction film is evidence of hinge abduction. Because radiographic changes may not be apparent for 3 to 6 months after the onset of the disease, bone scans and MRI have been investigated to provide an earlier diagnosis, but their clinical value is not clearly es- tablished. Although rarely necessary, gadolinium- enhanced MRI has been shown to correlate well with bone scan results in providing an early diagnosis of Legg-Calvé-Perthes disease. MRI without gadolinium enhancement was found to be poor for the evaluation of femoral head necrosis. Prognosis The long-term prognosis of Legg-Calvé-Perthes disease is improved with younger age of onset, especially with an onset in patients younger than 6 years, and also with less residual hip joint deformity at skeletal maturity. A recent study suggests that the percentage of physeal in- volvement on MRI scan may correlate better with long- term prognosis than the percentage of femoral head in- volvement. The Stulberg classification is the gold stan- dard for rating the residual femoral head deformity and joint congruence at skeletal maturity; however, a recent study has questioned the interobserver and intraob- server reliability of this five-tier grading scale. Lateral epiphyseal calcification and hip subluxation over 4 mm have been recognized as risk factors for poor prognosis. Although most patients with Legg-Calvé-Perthes dis- ease do well during adolescence and early adult life, by age 50 or 60 years 50% of patients develop disabling de- generative arthritis. A recent study indicates that con- trary to the popular belief that girls with Legg-Calvé- Perthes disease have a poorer prognosis, the outcomes for boys and girls with the disease are essentially equal. Figure 7 Lateral pillar classification. A, Herring group A, right hip with no loss of Treatment height in the lateral third of the epiphysis compared with the normal left hip. B, Less than 50% collapse of the lateral pillar is shown in the right hip, rendering it a Herring Initial treatment of Legg-Calvé-Perthes disease is typi- group B hip. C, A Herring group C hip with greater than 50% collapse of the lateral cally rest, activity restrictions, the use of nonsteroidal pillar. anti-inflammatory drugs, and physical therapy to regain hip motion. Bracing is no longer preferred because two its height is group B, and a lateral pillar that maintains less studies showed no significant effect using this treatment. than 50% of its height is group C. The increasing grade The goal of all treatments is to maintain motion of the within each classification system tends to correlate with a hip and to keep the femoral head contained within the poorer prognosis. acetabulum. Patients who lose substantial motion, who develop hinge abduction, or who start to subluxate or Hinge abduction, in which a bump deformity of the dislocate the hip joint may require more aggressive lateral femoral head prevents it from rotating under the treatment. Surgical treatment remains highly controver- acetabulum, is considered a poor prognostic sign. Hinge sial, but appears to be best suited for children older abduction can be seen on arthrogram taken with the pa- than 8 years with moderate femoral head involvement. tient under anesthesia, or can be inferred by comparing Preliminary results from a large multicenter trial show an AP hip radiograph obtained in neutral abduction that surgical treatment is associated with better out- 740 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics come in lateral pillar B and B/C border hips in patients This article explains and removes the confusion surround- who are age 8 years and older at onset. Surgical treat- ing this osteotomy. Results for 22 patients are presented. ment was not beneficial to lateral pillar A and C hips. Lateral pillar classification alone does not seem to be Guille J, Pizzutillo P, MacEwen G: Developmental dys- prognostic; however, taking into account other factors plasia of the hip from birth to six months. J Am Acad such as age of the patient and “head at risk” signs (such Orthop Surg 2000;8:232-242. as calcification lateral to the epiphysis, metaphyseal le- sions, lateral subluxation of the femoral head, and a hor- This article reviews diagnosis and management of DDH in izontal growth plate) improves the prognostic value. Pa- children from birth to age 6 months. tients who develop severe stiffness or whose femoral heads do not remain contained within the acetabulum Holen KJ, Tegnander A, Bredland T, et al: Universal or may benefit from Petrie casting with or without a soft- selective screening of the neonatal hip using ultra- tissue release. sound?: A prospective, randomized trial of 15,529 new- born infants. J Bone Joint Surg Br 2002;84:886-890. Femoral varus osteotomy and acetabular rotational osteotomy can also enhance containment but should The effect of screening was measured by the rate of late only be performed after hip stiffness is resolved preop- detection of dysplasia in children from age 6 to 11 years. Uni- eratively. Salvage procedures such as a shelf arthro- versal ultrasound screening was not statistically better than plasty or Chiari osteotomy or valgus femoral neck os- universal screening by physical examination, with ultrasound teotomy can be considered for severe disease. reserved for questionable cases. Some patients who have had Legg-Calvé-Perthes Konigsberg DE, Karol LA, Colby S, O’Brien S: Results disease will develop recurrence of pain and locking or of medial open reduction of the hip in infants with de- catching of the hip during their teenage years. Osteo- velopmental dislocation of the hip. J Pediatr Orthop chondritis dissecans or loose fragments of cartilage can 2003;23:1-9. develop and are best investigated with MRI or CT scan. The presence of an osteochondritis dissecans lesion in a Forty hips in 32 patients were reviewed at an average of patient who has had Legg-Calvé-Perthes disease is not 10.3 years after medial open reduction. Satisfactory results an indication for open or arthroscopic removal. Nonsur- were obtained in 75% of patients. The authors endorse the gical treatment seems to work well; the osteochondritis procedure as an option for patients younger than 1 year of dissecans lesion can end up in the cotyloid fossa where age. it will cause minimal complications. Older children with Legg-Calvé-Perthes disease can also develop labral Lerman JA, Emans JB, Millis MB, Share J, Zurakowski tears that can be treated with open or arthroscopic pro- D, Kasser JR: Early failure of Pavlik harness treatment cedures. for developmental hip dysplasia: Clinical and ultrasound predictors. J Pediatr Orthop 2001;21:348-353. Annotated Bibliography In 26 of 137 hips, Pavlik harness treatment failed to Developmental Dysplasia of the Hip achieve or maintain hip reduction. Univariate risk factors for failure were bilaterality, initial clinical examination, and initial Duppe H, Danielsson LG: Screening of neonatal insta- ultrasound percent coverage. bility and of developmental dislocation of the hip: A survey of 132,601 living newborn infants between 1956 Luhmann SJ, Bassett GS, Gordon JE, Schootman M, and 1999. J Bone Joint Surg Br 2002;84:878-885. Schoenecker PL: Reduction of a dislocation of the hip due to developmental dysplasia: Implications for the This article helps to illustrate the differences in detection need for future surgery. J Bone Joint Surg Am 2003;85- and treatment rates according to the experience of screeners A:239-243. and use of adjunctive ultrasound examinations. Reduction of dislocated hips before the appearance of an Eberle CF: Plastazote abduction orthosis in the manage- ossific nucleus resulted in only a slight increase in ischemic ne- ment of neonatal hip instability. J Pediatr Orthop 2003; crosis, but delay more than doubled the need for future sur- 23:607-616. gery. These authors do not recommend a delay. One hundred thirteen consecutive newborns with hip in- Sampath JS, Deakin S, Paton RW: Splintage in develop- stability on physical examination were treated with the Plasta- mental dysplasia of the hip: How low can we go? zote orthosis; only two required additional treatment and J Pediatr Orthop 2003;23:352-355. there were no instances of ischemic necrosis. Subluxatable hips at newborn examination were reexam- Grudziak JS, Ward WT: Dega osteotomy for the treat- ined. By treating only those hips with persistent instability at ment of congenital dysplasia of the hip. J Bone Joint 2 weeks, and those with persistent anatomic dysplasia at Surg Am 2001;83-A:845-854. 9 weeks, the rate of abduction splinting was lowered without adversely affecting outcomes. American Academy of Orthopaedic Surgeons 741

Hip, Pelvis, and Femur: Pediatrics Orthopaedic Knowledge Update 8 Sanchez-Sotelo J, Trousdale RT, Berry DJ, Cabanela Loder RT, Greenfield ML: Clinical characteristics of ME: Surgical treatment of developmental dysplasia of children with atypical and idiopathic slipped capital the hip in adults: I. Nonarthroplasty options. J Am Acad femoral epiphysis: Description of the age-weight test Orthop Surg 2002;10:321-333. and implications for further diagnostic investigation. J Pediatr Orthop 2001;21:481-487. An overview of the etiology, biomechanics, and principles of treatment of acetabular dysplasia is presented. Patients with SCFE who are younger than age 10 years or older than age 16 years and those with weight less than the Vitale MG, Skaggs DL: Devlopmental dyplasia of the 50th percentile are more likely to have an atypical (nonidio- hip from six months to four years of age. J Am Acad pathic) cause of SCFE such as renal failure, prior radiation Orthop Surg 2001;9:401-411. treatment, or endocrine disorder. This article reviews diagnosis and management of DDH in Schultz WR, Weinstein JN, Weinstein SL, Smith B: Pro- children from ages 6 months to 4 years. phylactic pinning of the contralateral hip in slipped cap- ital femoral epiphysis. J Bone Joint Surg Am 2002;84-A: Weintrob S, Grill F: Current concepts review: Ultra- 1305-1314. sonography in developmental dysplasia of the hip. J Bone Joint Surg Am 2000;82-A:1004-1018. A decision analysis formula based on probabilities of achieving a good long-term outcome supports prophylactic Methods, techniques, indications, and a critical analysis of pinning of the unslipped opposite hip. screening issues are discussed. Developmental Coxa Vara Tokmakova KP, Stanton RP, Mason DE: Factors influ- encing the development of osteonecrosis in patients Beals RK: Coxa vara in childhood: Evaluation and man- treated for slipped capital femoral epiphysis. J Bone agement. J Am Acad Orthop Surg 1998;6:93-99. Joint Surg Am 2003;85-A:798-801. This article presents an excellent and comprehensive re- In this study, osteonecrosis was found only with unstable view of coxa vara in children. SCFE (21 of 36 hips), and complete or partial reduction of un- stable SCFE was associated with a higher rate of osteonecro- Burns KA, Stevens PM: Coxa vara: Another option for sis. fixation. J Pediatr Orthop B 2001;10:304-310. Legg-Calvé-Perthes Disease The authors reported excellent fixation using a modified veterinary plate for valgus osteotomy in 9 patients (12 hips). Gigante C, Frizziero P: and Turra, S: Prognostic value of Catterall and Herring classification in Legg-Calve- Widmann RF, Hresko MT, Kasser JR, Millis MB: Wag- Perthes disease: Follow-up to skeletal maturity of 32 pa- ner multiple K-wire osteosynthesis to correct coxa vara tients. J Pediatr Orthop 2002;22:345-349. in the young child: Experience with a versatile “tailor- made” high angle blade plate. J Pediatr Orthop B 2001; A small study found that Catterall classification was not 10:43-50. prognostic but lateral epiphyseal calcification and epiphyseal subluxation greater than 4 mm were prognostic of poor out- By stacking Kirschner wires, the effect of a high angle come. Herring classification was only prognostic when com- blade plate was achieved in patients who were otherwise too bined with patient age. small for conventional internal fixation devices. Herring J, Kim H: Browne R: Abstract: Legg-Calve- Slipped Capital Femoral Epiphysis Perthes disease: A multicenter trial of five treatment methods. Pediatric Orthopaedic Society of North Amer- Futami T, Suzuki S, Seto Y, Kashiwagi N: Sequential ica Annual Meeting, Amelia Island, Florida, 2003, p26. magnetic resonance imaging in slipped capital femoral epiphysis: Assessment of preslip in the contralateral hip. Preliminary results of a landmark prospective study on the J Pediatr Orthop B 2001;10:298-303. outcome of Legg-Calvé-Perthes disease at maturity, showed that only lateral pillar B hips and borderline B/C hips of pa- MRI showed growth plate widening on T1 images as an tients age 8 years and older had improved outcome with sur- early sign of SCFE in patients with a preslip condition. gery. Lateral pillar A and lateral pillar B hips in patients younger than 8 years did well without treatment; there was no Kennedy JG, Hresko MT, Kasser JR, et al: Osteonecro- treatment effect for lateral pillar C hips. sis of the femoral head associated with slipped capital femoral epiphysis. J Pediatr Orthop 2001;21:189-193. Classic Bibliography Osteonecrosis was found only in unstable SCFE in 4 of 27 Castelein RM, Sauter AJ, de Vierger M, et al: Natural patients. The magnitude of slip and the magnitude of reduc- history of ultrasound hip abnormalities in clinically nor- tion in the unstable group was not predictive of a poorer out- mal newborns. J Pediatr Orthop 1992;12:423-427. come. 742 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 62 Hip, Pelvis, and Femur: Pediatrics Chiari K: Medial displacement osteotomy of the pelvis. Neyt JG, Weinstein SL, Spratt KF, et al: Stulberg classifi- Clin Orthop 1974;98:55-71. cation system for evaluation of Legg-Calve-Perthes dis- ease: Intra-rater and inter-rater reliability. J Bone Joint de Sanctis N, Rondinella F: Prognostic evaluation of Surg Am 1999;81:1209. Legg-Calve-Perthes disease by MRI: Part II. Pathomor- phogenesis and new classification. J Pediatr Orthop Pemberton PA: Pericapsular osteotomy of the ilium for 2000;20:463-470. treatment of congenital subluxation and dislocation of the hip. J Bone Joint Surg Am 1965;47:65-86. Ganz R, Klaue K, Vinh TS, Mast JW: A new periacetab- ular osteotomy for the treatment of hip dysplasias: Tech- Reinker KA: Early diagnosis and treatment of hinge ab- nique and preliminary results. Clin Orthop 1988;232: duction in Legg-Calve-Perthes disease. J Pediatr Orthop 26-36. 1996;16:3-9. Goldberg MJ, Harcke TH, Hirsch A, Lehmann H, Roy Salter RB, Dubos J-P: The first fifteen years’ personal DR, Sunshine P: Clinical practice guideline: Early detec- experience with innominate osteotomy in the treatment tion of developmental dysplasia of the hip (AC0001). of congenital dislocation and subluxation of the hip. Pediatrics 2000;105:896-905. Clin Orthop 1974;98:72-103. Graf R: Fundamentals of sonographic diagnosis of in- Salter RB, Thompson GH: Legg-Calve-Perthes disease: fant hip dysplasia. J Pediatr Orthop 1984;4:735-740. The prognostic significance of the subchondral fracture and a two-group classification of the femoral head in- Guille JT, Lipton GE, Szoke G, et al: Legg-Calve- volvement. J Bone Joint Surg Am 1984;66:479-489. Perthes disease in girls. J Bone Joint Surg Am 1998;80:1256. Schoenecker PL, Strecker WB: Congenital dislocation of the hip in children: Comparison of the effects of femoral Harcke HT, Kumar SJ: The role of ultrasound in the di- shortening and of skeletal traction in treatment. J Bone agnosis and management of congenital dislocation and Joint Surg Am 1984;66:21-27. dysplasia of the hip. J Bone Joint Surg Am 1991;73:622- 628. Staheli LT, Chew DE: Slotted acetabular augmentation in childhood and adolescence. J Pediatr Orthop 1992;12: Herring JA, Neustadt JB, Williams JJ, et al: The lateral 569-580. pillar classification of Legg-Calvé-Perthes’ disease. J Pediatr Orthop 1992;12:143-150. Stulberg SD, Cooperman DR, Wallensten R: The natural history of Legg-Calve-Perthes disease. J Bone Joint Surg Loder RT, Richards BS, Shapiro PS, Reznick LR, Aron- 1981;63:1095-1108. son D: Acute slipped capital femoral epiphysis: The im- portance of physeal stability. J Bone Joint Surg Am 1993; Tonnis D, Behrens K, Tscharani F: A midified technique 75:1134-1140. of the triple pelvic osteotomy: Early results. J Pediatr Orthop 1981;1:241-249. Malvitz TA, Weinstein SL: Closed reduction for congen- ital dysplasia of the hip: Functional and radiographic re- Walters R, Simon S: Joint destruction: A sequel of un- sults after an average of thirty years. J Bone Joint Surg recognized pin penetration in patients with slipped capi- Am 1994;76:1777-1792. tal femoral epiphysis, in The Hip. St. Louis, MO, CV Mosby, 1980, p 145. McAndrew MP, Weinstein SL: A long-term follow-up of Legg-Calve-Perthes disease. J Bone Joint Surg Am 1984; Weinstein SL, Ponseti IV: Congenital dislocation of the 66:860-869. hip: Open reduction through a medial approach. J Bone Joint Surg Am 1979;61:119-124. Meehan PL, Angel D, Nelson JM: The Scottish Rite ab- duction orthosis for the treatment of Legg-Calve- Perthes disease. J Bone Joint Surg Am 1992;74:2. American Academy of Orthopaedic Surgeons 743



Chapter 63 Knee and Leg: Pediatrics Kosmas J. Kayes, MD David A. Spiegel, MD Anterior Cruciate Ligament Injuries at Tanner stage 4 to 5 can probably be considered skele- tally mature and therefore receive adult treatments. If a Anterior cruciate ligament (ACL) tears in patients with child has more than 2 cm of growth remaining, ham- an open physis are on the rise, and optimum treatment string reconstruction should be considered to lessen the still remains controversial. Most of these injuries occur likelihood of injury to the physes. More importantly, during participation in sports activities. The mechanism careful attention should be paid to fixation to prevent is a noncontact, deceleration injury with a valgus stress damage to the physis. component or a hyperextension injury. Patients almost always report immediate pain and early onset of knee Primary repair of the ACL has never been shown to effusion. Accurate history and physical examination in be successful. Extra-articular reconstruction has a high the child younger than 12 years is often difficult because rate of failure (greater than 50%) over time and may children are not able to provide a good history. The ex- need to be revised with an intra-articular method when amination may not confirm the diagnosis with only 50% the child is skeletally mature. Intra-articular reconstruc- correlation of physical examination findings with find- tion in the skeletally immature patient carries the risk of ings on MRI or at time of arthroscopy. Most patients growth disturbance. This possibility needs to be weighed will have a positive Lachman test, but a pivot shift is of- against the inevitable risk of further and potentially ir- ten difficult to elicit. Effusion and loss of motion will be reversible risk of meniscal damage. Transepiphyseal present. techniques that avoid the physis potentially offer the so- lution but are technically demanding and not well stud- Imaging should consist of plain radiographs of the ied to date. The literature has reported instances of in- knee, including AP, lateral, tunnel, and Merchant views. jury to the physis in younger children after intra- MRI is the imaging study of choice for evaluation of an articular ACL reconstruction but most of these injuries ACL tear. Studies have shown that MRI can be just as are related to technical error in graft placement or fixa- accurate in adolescents with ACL injuries as in adults. tion. Specificity and sensitivity of clinical examination (done by experienced surgeons) and MRI were shown to cor- Partial tears of the ACL are unusual but do occur in relate well with findings at arthroscopy. However, in children younger than skeletal age 14 years with a nor- children younger than 12 years, MRI findings were sig- mal Lachman test; tears involving less than 50% of the nificantly lower in both sensitivity and specificity. fibers have been shown to respond well to nonsurgical reconstruction. Many MRI studies have shown partial In children with open physis at the knee, treatment tears of the ACL, however, no good data exist on which is still controversial. Modifying sports activity or not tears to treat surgically and which to treat nonsurgically participating in pivoting sports until near skeletal matu- with rehabilitation. rity are options, but often are not acceptable to the fam- ily and patient. Bracing and physical therapy may help Meniscal Tears but will not eliminate the possibility of recurrent epi- sodes of instability that expose the menisci to injury. Meniscal tears in children are still difficult to diagnose, Complete tears of the ACL are associated with a higher with many children not reporting a significant injury rate of meniscal injury than partial tears, and patients and physical examination being less reproducible, espe- with recurrent episodes of subluxation are at greater cially in children 12 years of age or younger. MRI can risk to eventually injure the meniscus. A teenager with have a higher false-positive rate for diagnosing meniscal nearly closed physes, with skeletal age 14 years or older tears because of increased vascularity of the meniscus in (boys tend to be 2 years behind in skeletal maturity children; diagnosis is improved with review by a good compared with girls of the same chronologic age), and pediatric skeletal radiologist. Tears of the medial menis- American Academy of Orthopaedic Surgeons 745

Knee and Leg: Pediatrics Orthopaedic Knowledge Update 8 cus are more common than lateral meniscal tears if dis- tures, respectively. Treatment of type I injuries is usually coid menisci are excluded. ACL tears have a 50% rate long leg casting with the knee in extension or 10° to 15° of associated meniscal tear. flexion for 4 to 6 weeks. Type II lesions can undergo closed reduction with hyperextension of the knee, then Meniscal repair should be attempted in children and long leg casting with close follow-up to check for dis- adolescents to preserve meniscal tissue if possible. Su- placement. If the fragment does not reduce to less than ture repair is still the gold standard, with the vertical 2 mm of displacement, then the same treatment as for mattress inside-out technique shown to be the strongest. type III lesions should be done. Type III fractures are Not only will peripheral tears or red-on-white tears typically treated with open or arthroscopic reduction of heal, but new evidence suggests that tears that extend the fragment and fixation to secure the fragment while into the white zone greater than 4 mm from the periph- it heals. ery had a 75% healing rate with stable inside-out repair. The anterior horn of the medial meniscus or the trans- Discoid Meniscus verse meniscal ligament may be trapped beneath the frag- ment in many patients and must be mobilized while the Discoid menisci occur in 3% to 5% of the population. fragment is reduced and then secured. Meniscal entrap- They are more often lateral, with 25% occurring bilater- ment is reported in 26% of type II injuries and more than ally. Discoid menisci are often asymptomatic but can be- 90% of type III injuries. Several different methods of fix- come symptomatic at any age. Symptoms often include ation have been reported, including use of Steinmann pain and popping in the lateral joint line and mechani- pins, cannulated screws into the fragment stopping short cal symptoms of catching and locking. The discoid me- of the physis, or suture technique through fibers of the niscus does not have the same strength characteristics as ACL at its base and then down through the crater, exiting a normal meniscus and can be more prone to tear with- out the anterior tibial epiphysis. out significant trauma. Classification by Watanabe con- sists of three types. In type I, the meniscus covers the Controversy exists as to whether long-term instabil- entire lateral plateau and is stable. In type II, the menis- ity continues, either objectively or subjectively, no mat- cus only covers part of the plateau and is stable. Type III ter how well the fragment is reduced. The thought is discoid menisci (Wrisberg variant) are unstable because that some ligaments undergo appreciable interstitial of absent meniscotibial attachment posteriorly. failure before the fracture and that even if the fracture is reduced, the ligament may have residual laxity. Most Treatment in asymptomatic patients with no tear is reports show that even if there is some objective laxity observation. For symptomatic patients, treatment con- on clinical examination, most patients (84%) return to sists of repair or débridement if a tear is present and their previous level of activity. A recent report on a saucerization of the meniscus. For type III unstable me- small number of patients demonstrates that residual lax- nisci, suture stabilization to the capsule is necessary ity may not be inevitable because good results with min- along with saucerization. Complete meniscectomy imal objective or subjective laxity were obtained. should be avoided because the meniscus will not regen- erate. Juvenile Osteochondritis Dissecans Tibial Eminence Fracture Juvenile osteochondritis dissecans refers to an osteo- chondritis dissecans lesion that occurs before physeal Avulsion of the tibial eminence occurs with a mecha- closure. An avascular portion of the subchondral bone nism similar to an ACL tear. Usually occurring between in severe cases can undergo separation from the under- 8 to 14 years of age, the attachment of the ACL on the lying epiphyseal cancellous bone. The cartilage sepa- tibial eminence is avulsed off, bringing a varying amount rates with the subchondral bone, although sometimes of bony fragment with it. Historically, these injuries oc- there is very little bone remaining on the back side of curred after a fall from a bicycle, but recently more are the cartilage. The severity ranges from minimal involve- reported from mishaps during skiing or while playing ment that results in a soft cartilage bed to complete sep- football. The mechanism of injury is usually forceful hy- aration with production of a loose body. The etiology of perextension or a direct blow to the distal end of the fe- this disease is unknown but is highly associated with re- mur with a flexed knee. A high incidence of associated petitive microtrauma and/or vascular disruption. Boys injuries (up to 40%) such as medial collateral ligament are affected twice as often as girls, and most patients are (MCL) injuries or meniscal tears has been reported. very active in sports, giving credence to the theory of trauma as an etiology. The lateral aspect of the medial Meyers and McKeever classify injuries into three femoral condyle is most often involved (75%). The lat- types. Type I is nondisplaced, type II is elevation of the eral condyle, patella, trochlea, and tibial plateau can also anterior fragment up to 3 mm with the posterior hinge develop lesions but are affected much less often. The intact, and type III is complete displacement of the posterior aspect of the lateral femoral condyle can have avulsed fragment; they occur in approximately 15%, 39%, and 45% of patients with tibial eminence frac- 746 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 63 Knee and Leg: Pediatrics normal variations in ossification that can mimic an os- trochlea, tibia, and patella do not have as good a re- teochondritis dissecans lesion on plain radiographs. sponse to the same treatment. Approximately 50% of patients describe a history of With larger lesions, newer techniques of cartilage res- trauma to the knee with reports of ongoing, vague knee toration can be considered. At a mean 5-year follow-up pain during athletic activities. The pain often improves (range, 1 to 10 years) of autologous chondrocyte trans- with rest. Mechanical symptoms of locking, catching, or plantation, 90% of patients had good results. However, popping can occur when the condition is more advanced only seven patients in this study were younger than 18 and loose fragments are present. Patients may have pain years. Mosaicplasty gave the same results at the same with palpation over the condyle that is involved. Effu- length of follow-up; again, most patients who were treated sion may or not be present. had adult-onset lesions. The outcome of these procedures in the younger population is still unknown because results A tunnel view is important, along with an AP and are not separated from those found with adult-onset le- lateral view of the knee, as many lesions are best seen sions. on the tunnel view. MRI can be helpful in making treat- ment decisions. MRI stage I lesions have articular carti- Tibial Tubercle Fractures lage thickening but no break in the cartilage. Stage II le- sions have a break in the cartilage but no increased These fractures are rare and account for approximately signal intensity on T2-weighted images between the 2% of all epiphyseal fractures. The mechanism of injury bone fragment and the intact subchondral bone. Stage is usually jumping or landing during some type of sports III lesions have the increased signal intensity at this in- activity, often basketball or track. The force of the mas- terface, an indication that fluid is present between the sive quadriceps contraction on takeoff or landing fragment and the host bone. This finding is a sign of in- against the acutely flexing knee pulls off the tubercle. stability of the fragment. Stage IV lesions are loose bod- ies. MRI with gadolinium enhancement helps to distin- The Watson-Jones classification of these fractures in- guish between type II and type III lesions cludes type I (the fracture line is between the ossifica- tion centers of the tibial tubercle and the epiphysis be- Treatment in skeletally immature patients with a sta- fore closure), type II (the fracture pattern courses ble lesion depends on the symptoms. Patients with open between the tibial tubercle and the plateau), and type physes have a better prognosis for healing of the lesions. III (the fracture extends vertically behind the tibial tu- If the patient is relatively asymptomatic, then activity bercle and through the tibial plateau). A few instances restriction alone may be enough. However, if symptoms have been reported in which a tubercle avulsion frac- of pain and joint effusion are present, restricted weight ture with an accompanying epiphyseal fracture, either bearing and possibly immobilization may be warranted Salter-Harris II, III, or IV occurs (making a case for a for 6 weeks. Range-of-motion exercises should be per- type IV tibial tubercle fracture pattern). These types of formed out of the brace. This treatment plan can result fractures are extremely rare but can have higher poten- in healing in up to 90% of patients at 3 to 6 months. If tial for compartment syndrome. symptoms persist or the MRI signal does not change, then drilling of the lesion may be indicated. This proce- Treatment of nondisplaced type I injuries is cast im- dure helps induce vascular supply into the lesion and fa- mobilization for 6 weeks with the leg in extension. Dis- cilitates healing. The lesions may be drilled retrograde placed type II and III lesions require open reduction and through a portal while visualizing through the scope or screw fixation for stability. Meniscal injury can also occur antegrade with fluoroscopic guidance to avoid penetrat- in type III fractures. Most injuries occur in older children ing intact cartilage. just before physeal closure and heal well; however, if this injury occurs in younger children, smooth pin fixation If the lesion is unstable (type III or IV), surgical in- should be considered to avoid further damage to the prox- tervention is indicated. If subchondral bone is present, imal tibial physis. Children may have resultant recurvatum the bed can be débrided and drilled and the fragment deformity if younger than 11 years at the time of injury. fixed with pins or screws. Results are variable with fixa- tion. If there is no subchondral bone on the fragment, Distal Femoral Physeal Fractures the piece should be removed and the bed débrided and drilled. Other options include autologous chondrocyte These fractures comprise less than 1% of all pediatric transplantation and osteochondral grafts. If the lesion is fractures and about 5% to 6% of physeal fractures. The smaller than 2.5 cm, débridement of the frayed cartilage, undulation of the physis contributes to its stability. The drilling, or microfracture may allow the lesion to heal mechanism of injury is usually a football injury or being with fibrocartilage. In larger lesions, fixation of the frag- hit by a motor vehicle. Concomitant ligament injury ment should be attempted only if there is subchondral may occur in up to 50% of patients but often is unrec- bone attached to the cartilage. Lesions on the medial ognized initially. Most injuries are closed, and patients femoral condyle tend to respond the best; lesions of the have pain, deformity, inability to bear weight, and knee effusion (if the fracture is intra-articular). American Academy of Orthopaedic Surgeons 747

Knee and Leg: Pediatrics Orthopaedic Knowledge Update 8 Salter-Harris type II fractures are the most common V account for 3% of these injuries. Type V patterns are pattern and are seen in adolescents. The risk of growth not usually not noticed until deformity occurs after the in- arrest is significant (between 19% to 25%) even in this jury. pattern. Salter-Harris type III fractures usually result from a valgus stress and involve the medial condyle. Treatment of Salter-Harris type I and II patterns is These fractures may be minimally displaced. Salter- casting for 6 to 8 weeks if nondisplaced and gentle Harris type IV is uncommon and Salter-Harris type V is closed reduction, often under general anesthetic, if dis- extremely rare, with the diagnosis often made later after placed. Crossed pins should be considered for stability deformity occurs from growth disturbance. Infants re- or cannulated screws should be used if the metaphyseal spond to remodeling and require minimal reduction fragment if large enough. Salter-Harris type III and IV even with significant displacement. In adolescents, mini- patterns require open reduction and internal fixation if mal remodeling of varus/valgus can be expected; there- any displacement is present. They can be fixed with can- fore, reduction needs to be near anatomic. nulated screws across the epiphysis for type III and across both metaphysis and epiphysis for type IV. These Treatment of nondisplaced Salter-Harris type I and injuries can cause unrecognized arterial damage and II fractures consists of cast immobilization with close lead to compartment syndrome. follow-up. If reduction is required, these injuries are un- stable and fixation should be considered. Smooth Stein- Congenital Dislocation of the Knee mann pins crossed in the metaphysis are effective for Salter-Harris type I and II fractures with a small meta- Congenital knee dislocation is a spectrum of deformity physeal fragment. If the metaphyseal fragment is large from simple positional contractures that correct sponta- enough, cannulated screws can be used transversely neously to rigid dislocation of the knee joint requiring through the metaphyseal fragment into the remaining surgical intervention. The condition often occurs in chil- metaphysis, thereby avoiding the physis. Salter-Harris dren with myelomeningocele, arthrogryposis, or other type III and IV fracture patterns require anatomic re- syndromes such as Larsen’s. This deformity is often as- duction. If no displacement is present, simple immobili- sociated with developmental dysplasia of the hip, club- zation is adequate; however, most Salter-Harris type III foot, and metatarsus adductus. It is extremely important and IV fractures will require open anatomic reduction to look for associated hip dysplasia when a knee and fixation. Cannulated screws placed parallel to the dislocation is present. The deformity is recognized at physis, which travel transversely across the epiphysis birth with a knee that is hyperextended and a foot that and the metaphysis, are excellent constructs. is extended toward the patient’s head because of a flexed hip. The pathology consists of one or all of the Proximal Tibial Physeal Fractures following conditions: contractures of the quadriceps ten- don, an absent suprapatellar pouch, tight collateral liga- Proximal tibial physeal fractures are rare injuries occur- ments, and anterior subluxation of the hamstring ten- ring in patients age 8 to 15 years. Half of these fractures dons. result from motor vehicle crashes and half from injury during sports participation. They can also be found in If the condition results from positioning in utero, of- the newborn and in patients with arthrogryposis who ten the deformity is mild and the knee is still fairly flex- have undergone aggressive stretching in an attempt to ible. The knee will correct spontaneously within a few improve range of motion. The mechanism of injury can weeks or can be assisted by gentle range-of-motion ther- be a direct force, flexion injury, or abduction with or apy to accelerate correction. Serial casting also may be without hyperextension of the lower leg. An associated helpful if hip dysplasia is present. A Pavlik harness is MCL injury may be present, especially in Salter-Harris applied once knee range of motion increases enough to type III fractures. allow proper fit. Salter-Harris type fractures account for 15% of the in- A more severe contracture or true dislocation shows juries and about half are nondisplaced. For those that are minimal response to stretching and casting. This condi- displaced, the metaphyseal portion typically is displaced tion usually is evident within the first 3 months of treat- medially or posteriorly. Salter-Harris type II fracture pat- ment. Failure to gain 30° of knee flexion by 3 months is terns (43%) are nondisplaced in up to two thirds of pa- an indication for surgery. Surgical treatment is with V-Y tients. When displacement does occur, the metaphyseal quadricepsplasty or Z-lengthening of the tendon, re- fragment is usually displaced medially. Salter-Harris type lease of the anterior joint capsule, transposition posteri- III fractures (22%) usually involve the lateral epiphysis, orly of the hamstring tendons, and mobilization of the and the MCL is often torn in this pattern. Salter-Harris collateral ligaments. Ninety degrees of knee flexion type IV fractures account for 27% and Salter-Harris type should be achieved and then the knee should be placed in a cast in 45° to 60° flexion for 3 to 4 weeks. 748 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 63 Knee and Leg: Pediatrics Congenital Dislocation of the Patella Treatment options vary but generally follow the same guidelines as for adult fractures. Nondisplaced A true congenital dislocation of the patella is rare. This fractures can be treated in a cast. For displacement entity must be distinguished from a recurrent disloca- greater than 3 mm, open reduction and fixation is rec- tion that occurs later in life. In congenital dislocation of ommended. Small fracture pieces may be excised and the patella, the patella is hypoplastic or absent, and the screw fixation of a larger fragment should be consid- femoral trochlea is often flattened. The lateral retinacu- ered. lum is tight, and the patella is completely dislocated lat- erally. The patella is often adherent to the iliotibial band Evaluation of Genu Varum in Infants and and often irreducible over the condyle. Genu valgus is Children often present, as is a flexion contracture of the knee. Surgical intervention is required and involves extensive Bowing of the lower extremities in infants and children lateral retinacular release, often to the greater tro- is a common reason for referral to an orthopaedic sur- chanter, medial plication, and either hamstring tenodesis geon. Infantile genu varum is physiologic in most in- or transfer of one half of the patellar tendon. stances. Pathologic causes include infantile Blount’s dis- ease, skeletal dysplasias, rachitic syndromes (nutritional Nail-Patella Syndrome or metabolic), posttraumatic or postinfectious deformi- ties, and rarely, focal fibrocartilagenous dysplasia. Nail-patella syndrome is rare, involving a tetrad of or- thopaedic manifestations: (1) nail dysplasia; (2) hypo- Historical features that elevate the index of suspi- plastic (or absent) and often dislocated patellae; (3) iliac cion for infantile Blount’s disease include obesity, early horns; and (4) elbow dysplasia, mostly consisting of ra- ambulation, race (African American), and rarely, a posi- dial head dislocation. The syndrome is of autosomal tive family history. The deformity is localized to the dominant inheritance with great variability in the phe- proximal tibia, in contrast to physiologic bowing, where notype. Foot abnormalities may also accompany the di- the deformity is usually more evenly distributed agnosis, as well as upper and lower extremity tendon throughout the diaphyseal region. A varus thrust also contractures. The foot deformities include metatarsus should raise the index of suspicion. adductus, pes planus, equinus, clubfoot, vertical talus, and calcaneovalgus. Many patients have nephropathy A host of radiographic parameters have been inves- and glaucoma. tigated to screen for the development of infantile Blount’s disease (Figure 1). The tibial metaphyseal- The orthopaedic implications primarily involve the diaphyseal angle (TMDA) is most frequently used for patellar dislocations. Most patients will require early this purpose. The TMDA has been shown in several surgical intervention to stabilize the extensor mecha- studies to be effective (< 5% error) for angles less than nism and prevent long-term complications. Surgical 9° (physiologic) or greater than 16° (Blount’s); however, treatment is with lateral release (extensive), medial pli- a significant percentage of cases may be indeterminate cation, and hemipatellar tendon transfer or hamstring (9° to 16°). tenodesis. The nail problems are usually well tolerated. Surgery for radial head dislocation is usually not needed In an attempt to improve the accuracy of radio- because patients usually will not have significant com- graphic screening, several other measurements have plications. The iliac horns are asymptomatic. been evaluated for their sensitivity, specificity, and pre- dictive value. Both the percentage of tibial deformity Patellar Fracture (tibial varus/total limb varus) and the ratio of the femo- ral metaphyseal-diaphyseal angle to the TMDA may be Fractures of the patella are uncommon in children more sensitive and more specific than the TMDA alone. younger than 16 years. Diagnosis in the younger patient The epiphyseal-metaphyseal angle (EMA) may also be is difficult and often delayed. The mechanism of injury helpful because patients 1 to 3 years of age with a is by direct impact or contraction of the quadriceps TMDA of 10° or greater and an EMA of greater than muscle. Osteochondral fractures are more likely in the 20° are at increased risk for Blount’s disease. Serial ra- younger age group, especially after a dislocation event. diographs are often required to establish the diagnosis, Avulsion fractures are classified by location. Superior and a comprehensive approach to screening should in- pole avulsion is least common; medial avulsion is often clude both standardized measurements and knowledge caused by dislocation of the patella and is the most of the sequential radiographic changes described by common, followed by inferior pole avulsion. Lateral Langenskiöld. avulsion must be distinguished from the congenital vari- ant bipartite patella. Often a larger fragment is frac- Blount’s Disease tured off than appears on radiographs because of the large cartilaginous portion. Infantile Blount’s disease is a progressive varus defor- mity of the proximal tibia. The etiology is most likely multifactorial, and the pathophysiology involves a dis- American Academy of Orthopaedic Surgeons 749

Knee and Leg: Pediatrics Orthopaedic Knowledge Update 8 Figure 1 Radiographic indices used in the evaluation of lower extremity bowing in infants and children. A, Tibiofemoral angle (mechanical). This is the angle in between a line drawn from the center of the hip to the center of the knee and a line from the center of the knee to the center of the ankle. B, TMDA. The TMDA has been used most commonly and is measured as the angle between a line drawn though the most distal aspect of the medial and lateral beaks of the proximal tibia and a line perpendicular to the anatomic axis (most reproducible if drawn along the lateral tibial cortex). C, Femoral metaphyseal-diaphyseal angle. This angle is measured in between the anatomic axis of the femur and a line drawn perpendicular to a line parallel to the distal femoral physis. D, Epiphyseal-metaphyseal angle. This represents the angle between a line drawn through the proximal tibial physis (parallel to the base of the epiphyseal ossification center) and a line connecting the midpoint of the base of the epiphyseal ossification center with the most distal point on he medial beak of the tibia. E, Percent deformity of the tibia ([%DT] = tibial varus [TV]/total limb varus). The %DT is calculated as the degree of tibial varus (angle between the mechanical axis of the tibia and a line parallel to the distal femoral condyles) divided by the total limb varus (tibial varus + femoral varus [FV]). Femoral varus represents the angle between the mechanical axis of the femur and the line parallel to the distal condyles of the femur. turbance of growth in the posterior and medial regions distal fragment should be translated laterally. An intra- of the proximal tibia, most likely caused by mechanical operative arthrogram facilitates visualization of the tib- overload in a genetically susceptible individual. The se- ial joint surface. The lowest risk of recurrence is seen in quence of radiographic changes that evolves over the those with Langenskiöld III disease who are younger first decade of life has been described by Langenskiöld. than 4 years. Unfortunately, recurrence remains com- Plain radiographs may suggest a depression in the me- mon even after a well-executed osteotomy. dial tibial plateau in later stages of the disease; however, arthrography (or MRI) often reveals that this region is Although MRI is not routinely indicated, it may be occupied by unossified cartilage. helpful in documenting the presence, size, and location of a physeal bar in later stages of the disease. Treatment The best outcomes are associated with early diagno- of a physeal bar must be individualized. In addition to sis and unloading of the medial joint by either bracing angular correction, either a resection of the bar or a lat- or osteotomy. Although somewhat controversial, a knee- eral hemiepiphysiodesis may be required. Limb lengths ankle-foot orthosis may be indicated for patients with should be followed closely, and either lengthening or stage I and II disease who are younger than 3 years. The contralateral epiphysiodesis may be indicated. device should be worn at least during weight-bearing hours, and desirable features include a drop lock and a Adolescent or late-onset Blount’s disease also in- valgus producing strap. volves a progressive varus deformity of the proximal tibia and is diagnosed in children older than 8 years. Valgus osteotomy is indicated for patients with pro- Most patients are obese, and mechanical overload has gressive deformity. Overcorrection is essential, and the been implicated. A common radiographic feature is wid- 750 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 63 Knee and Leg: Pediatrics Table 1 | Clinical Findings in the Ipsilateral Extremity That May Be Observed in Patients With Longitudinal Deficiency of the Tibia and Fibula Fibular Deficiency Tibial Deficiency Figure 2 Common osseous anatomy of fibular (A) and tibial (B) deficiency. Femur Femur Shortening Hypoplasia ening and irregularity of the medial proximal tibial phy- External rotation PFFD sis, which is consistent with a chronic compressive in- Lateral condylar hypoplasia jury. This multiplanar deformity includes varus, PFFD Knee procurvatum, and internal torsion. Treatment is by os- Coxa vara Absent cruciates teotomy or hemiepiphysiodesis, and suggested advan- Knee Dysplastic or absent patella tages of external fixation include the ability to address Absent or attenuated cruciate all components of the deformity, to minimize neurovas- Tibia cular complications by enabling a gradual correction, to ligaments Deficient or absent make adjustments in alignment postoperatively based Genu valgum on standing radiographs, and to enable simultaneous Patellar dysplasia and/or Fibula limb lengthening. Hemiepiphysiodesis may be consid- Angulation (varus, posterior) ered for milder deformities in patients with sufficient subluxation Proximal instability/dislocation growth remaining. A coexisting deformity of the distal Tibia Ankle femur may require either hemiepiphysiodesis or osteot- Shortened Fibulocalcaneotalar articulation omy. Anteromedial bowing Fibula Foot Longitudinal Deficiency of the Fibula Hypoplastic or absent Equinovarus Tarsal coalition Given the spectrum of coexisting abnormalities associ- Ankle Longitudinal deficiency (medial) ated with longitudinal deficiency of the fibula (Figure 2 Valgus and Table 1), postaxial hypoplasia is a term that has Ball and socket been suggested as more comprehensive in describing Foot this condition. The treatment plan must address limb Equinovalgus length inequality, foot and ankle deformity, and coexist- Tarsal coalition ing abnormalities such as valgus at the knee and ankle. Longitudinal deficiency (lateral) Growth inhibition varies from 5% to 30% and the fe- Fused metatarsals PFFD = proximal femoral focal deficiency mur contributes to limb shortening in up to 50% of pa- tients. Classification schemes have traditionally focused on the degree of fibular deficiency and the predicted limb length inequality; however, both the treatment and prognosis also depend on deformity of the foot and an- kle. Fibular morphology does not seem to correlate with either the percentage of growth inhibition or the degree of foot deformity; therefore, treatment recommenda- tions should not be based solely on the degree of fibular deficiency. Congenital lower extremity deficiencies are associated with a constant percentage of growth inhibi- tion; thus, the discrepancy at maturity can be estimated at an early age. The position of the foot of the shorter extremity relative to the longer extremity also may be used to estimate the percentage of shortening at skeletal maturity (proximal one third ≥ 26%, middle one third approximately 16% to 25%, distal one third ≤ 15%). The treatment should be individualized. Patients with a functional (or reconstructable) foot and a milder American Academy of Orthopaedic Surgeons 751

Knee and Leg: Pediatrics Orthopaedic Knowledge Update 8 Figure 3 The Kalamchi and Dawe classification for longitudinal deficiency of the tibia. A, Type I represents complete absence of the tibia. B, Type II deficiencies are associated with absence of the distal tibia. C, Type III deficiencies have a distal tibial deficiency (hypoplasia) with a diastasis of the distal tibiofibular articulation. projected discrepancy may be treated by foot recon- Longitudinal Deficiency of the Tibia struction and an epiphysiodesis, a single lengthening procedure, or both. A foot with three or more rays can A spectrum of limb abnormalities is seen in patients potentially be treated by reconstruction rather than am- with partial or complete absence of the tibia. Clinical putation. Those extremities with a nonfunctional foot concerns include instability at the knee and the ankle, and/or a large projected limb-length discrepancy (up to an equinovarus foot deformity with or without the loss 25 cm) are most commonly treated by amputation of medial rays, and limb-length discrepancy. The classifi- (Syme or Boyd). In general, most patients with com- cation scheme presented by Kalamchi and Dawe is per- plete absence of the fibula require amputation. The indi- haps most practical (Figure 3). The condition occurs cations for amputation versus limb salvage remain neb- sporadically; however, both autosomal dominant and ulous for the subset of patients with a functional (or autosomal recessive forms of transmission have been reconstructable) foot and a large projected discrepancy. documented. In contrast to fibular deficiencies, associ- Although a staged reconstruction including two or three ated congenital anomalies in the musculoskeletal system lengthening procedures is technically feasible, it remains (most often in the hand) and the viscera (congenital to be determined whether limb function and patient sat- heart disease, testicular anomalies) have been reported isfaction will be enhanced compared with early amputa- in patients with tibial deficiencies. tion. The psychosocial impact of multiple reconstructive procedures during childhood and adolescence must also Complete absence of the tibia is usually treated by be considered. through knee amputation. A small subset of patients with a strong quadriceps muscle and no knee flexion Coexisting deformities must also be addressed to contracture may be candidates for fibular centralization maximize outcome. The severity of ankle valgus corre- (Brown procedure). Because a significant subset of lates with the degree of fibular deficiency. There is typi- these patients may subsequently require an amputation cally a wedge-shaped distal tibial epiphysis and a tarsal for progressive flexion contracture, most physicians coalition. Milder degrees of ankle valgus may be treated have abandoned this procedure. When the proximal by hemiepiphysiodesis, whereas techniques to restore tibia has ossified, stability is achieved by proximal ti- the lateral buttress in patients with greater deformity in- biofibular synostosis, and either amputation (Syme or clude fibular lengthening or distal tibial osteotomy. Val- Boyd) or foot salvage is also performed depending on gus deformity at the knee results from hypoplasia of the the local anatomy. Two or more limb lengthenings may lateral femoral condyle, and treatment options include a be required if the foot is retained, and the patient’s fam- distal femoral osteotomy or distal femoral hemiepiphys- ily must be prepared for the effects on the patient of iodesis (open versus physeal stapling). Anteromedial multiple procedures throughout childhood and adoles- bowing of the tibia is common but typically only re- cence. quires an osteotomy in patients with complete absence of the fibula. The third major type of deformity involves hypopla- sia of the distal tibia associated with a diastasis between the distal tibia and fibula, for which the most common 752 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 63 Knee and Leg: Pediatrics treatment has been early Syme or Boyd amputation. tibial fragments. A coexisting pseudarthrosis of the fib- Limbs with lesser degrees of anticipated discrepancy ula worsens the prognosis and should be treated by re- and a functional (or reconstructable) foot may be con- section and grafting as well. Intramedullary fixation of sidered for salvage, and the choice of procedure is based the fibula should be considered. Ankle valgus may be on the local anatomy. Options for ankle stabilization in- treated by medial distal tibial hemiepiphysiodesis or dis- clude arthrodesis of either the distal tibia or fibula to ei- tal tibiofibular synostosis because a distal tibial osteot- ther the talus or the calcaneus. Talectomy may be re- omy may fail to unite. quired to facilitate closure of the diastasis, and synostosis of the distal tibia to the fibula may be re- There has been considerable interest in the use of quired to maintain stability. An osteotomy of the distal external fixation and distraction osteogenesis. Following tibia and fibula also may be required to correct angular resection of the pathologic tissue, acute shortening and deformity, and limb-length discrepancy will need to be compression at the pseudarthrosis site may be combined treated by one or more lengthenings and/or epiphysiod- with bone transport via a proximal tibial corticotomy. esis. Excellent rates of union have been reported; however, refracture remains a concern. The technique is most ap- Congenital Pseudarthrosis of the Tibia propriate for children older than 5 years. Intramedullary and/or Fibula fixation may help to protect against refracture once union has been achieved. The etiology of congenital pseudarthrosis of the tibia re- mains unknown, and the pathophysiology appears to in- Free vascularized fibular grafting results in union volve a localized deregulation of bone modeling and rates of 92% to 95%; however, additional procedures growth. The condition is associated with neurofibroma- are commonly required for delayed union at the distal tosis in approximately 50% of patients; however, only transfer site, for refracture or stress fractures, for ankle 10% of patients with neurofibromatosis will develop valgus, and for limb-length discrepancy. Pseudarthrosis pseudarthrosis of the tibia. In contrast to anterolateral may recur above or below the site of transfer. Donor bowing of the tibia, which is associated with a “prepseud- site morbidity (weakness, ankle valgus) remains a con- arthrosis” or frank pseudarthrosis of the tibia, postero- cern, and restoring fibular continuity by grafting of the medial bowing is generally benign and improves with periosteal envelope, or by distal tibiofibular fusion, time. However, patients with posteromedial bowing will should be considered. Ipsilateral fibular transfer may be require either an epiphysiodesis or a limb lengthening considered in those with no evidence of fibular involve- to treat limb-length discrepancy. ment. The goal of treatment is not only to obtain union, Amputation is most commonly performed for resis- but also to prevent progressive deformity/refracture, to tant pseudarthroses following multiple attempts to treat coexisting limb-length discrepancy and ankle val- achieve union or when union has been achieved but gus, and to maximize function of the foot and ankle. function is impaired by chronic pain or stiffness. The Follow-up beyond skeletal maturity is required to deter- Syme or Boyd techniques are preferred in children, mine the outcome of a given treatment method. There is whereas below-knee amputation may be considered in evidence to suggest that delaying surgery may increase skeletally mature patients. the chances of achieving union and that results of treat- ment may be better in patients presenting for surgery at Isolated congenital pseudarthrosis of the fibula is ex- a later age (older than 5 years). tremely rare. The lesion is typically in the distal third, and the goals of treatment are to restore fibular conti- For patients with anterolateral bowing and a pre- nuity and to prevent or treat ankle valgus. Although ob- pseudarthrosis, the goal is to prevent or delay fracture servation or splinting may be an option in the absence by full-time immobilization in a clamshell ankle-foot of a progressive ankle valgus, an attempt to restore fibu- orthosis or similar device. Prophylactic bypass grafting lar continuity by resection, bone grafting, and intramed- has not been widely accepted. The primary goal for an ullary fixation is generally recommended. In younger established pseudarthrosis is to achieve union. Princi- children, valgus may improve with growth if union is ples of surgery include resecting all abnormal tissue, achieved. Arthrodesis of the distal fibula to the distal providing a stable mechanical environment, and grafting tibia may be performed as an alternative to resection with autogenous bone. The role of electrical stimulation and grafting or following failed attempts to achieve as an adjunct has yet to be determined. union at the pseudarthrosis. The procedure will prevent the progression of ankle valgus in older children and ad- Resection and grafting with intramedullary fixation olescents but will not result in correction of valgus. The has been associated with variable rates of union (28% most common treatment of an established valgus defor- to 80%); concomitant fibular surgery may improve the mity is either distal tibial hemiepiphysiodesis or osteot- outcome. In the absence of fibular involvement, osteot- omy. omy is usually required to facilitate apposition of the American Academy of Orthopaedic Surgeons 753

Knee and Leg: Pediatrics Orthopaedic Knowledge Update 8 Annotated Bibliography No patient had any objective instability on KT-1000 testing and no functional limitations in high-demand sporting activi- Anterior Cruciate Ligament Injuries ties. Anderson AF: Transepiphyseal replacement of the ante- Juvenile Osteochondritis Dissecans rior cruciate ligament in skeletally immature patients. J Bone Joint Surg Am 2003;85-A:1255-1263. Peterson L, Minas T, Brittberg M, Lindahl A: Treatment of osteochondritis dissecans of the knee with autologous In this small study, skeletally immature patients with ACL chondrocyte transplantation. J Bone Joint Surg Am tears were treated with transepiphyseal ACL reconstruction, 2003;85-A(suppl 2):17-24. thereby avoiding crossing the physis with the grafts. The tech- nique is demanding but safe and provided effective treatment Fifty-eight knees underwent autologous chondrocyte in this population. transplantation for osteochondritis dissecans lesions (average of 5.7 cm2). Mean age at the time of surgery was 26.4 years Kocher MS, Micheli LJ, Zurakowski D, Luke A: Partial and mean follow-up was 5.6 years. The population was mixed tears of the anterior cruciate ligament in children and regarding lesion size, location, and time of onset (skeletally adolescents. Am J Sports Med 2002;30:697-703. mature versus immature). Ninety-one percent of patients had good or excellent results at follow-up based on clinical evalua- Partial ACL tears diagnosed by MRI and arthroscopically tion and self-assessment questionnaires. confirmed were studied in 45 skeletally mature and 17 skele- tally immature patients. Patients who had good outcomes with Nail-Patella Syndrome nonreconstructive treatment were younger than skeletal age 14 years, had normal or near-normal results on the Lachman Beguiristain JL, De Rada PD, Barriga A: Nail-patella and pivot shift tests, and had 50% or less predominantly poste- syndrome: Long-term evolution. J Pediatr Orthop B rolateral tears. Patients not meeting those criteria required re- 2003;12:13-16. constructive treatment for a good result. Eight patients with knee pain caused by patellar instability Meniscal Tears were reviewed. Five patients were treated surgically and three were not treated. Noyes FR, Barber-Westin SD: Arthroscopic repair of meniscal tears extending into the avascular zone in pa- Evaluation of Genu Varum in Infants and Children tients younger than twenty years of age. Am J Sports Med 2002;30:589-600. Bowen RE, Dorey FJ, Moseley CF: Relative tibial and femoral varus as a predictor of progression of varus de- In this prospective study, 71 meniscal tears extending into formities of the lower limbs in young children. J Pediatr the avascular zone in patients younger than 20 years were ex- Orthop 2002;22:105-111. amined at an average follow-up of 18 months postoperatively. The repairs were all made with an inside-out vertical divergent Progression of varus deformity was evaluated with six ra- suture technique. Seventy-five percent of these patients had diographic measurements. The percentage of tibial deformity good results with no evidence of ongoing symptoms in the ti- (tibial varus/total limb varus) was more sensitive and more biofemoral compartment. specific than the metaphyseal-diaphyseal angle. All patients with both a deformity of the tibia greater than 50% and a TMDA greater than 16° experienced progression of deformity. Tibial Eminence Fracture Davids JR, Blackhurst DW, Allen BL Jr: Radiographic evaluation of bowed legs in children. J Pediatr Orthop Owens BD, Crane GK, Plante T, Busconi BD: Treatment 2001;21:257-263. of type III tibial intercondylar eminence fractures in skeletally immature athletes. Am J Orthop 2003;32:103- The sensitivity, specificity, and positive predictive value of 105. the mechanical axis, the TMDA, and the EMA were evaluated in children 1 to 3 years of age. Those with a TMDA of 10° or In this study, 12 patients with type III tibial eminence frac- greater and an EMA of greater than 20° are at increased risk tures had good results with absorbable suture repair. These for Blount’s disease. patients had 1 mm or less residual laxity at an average follow-up of 36 months. Five of the 12 patients had associated McCarthy JJ, Betz RR, Kim A, et al: Early radiographic injuries, including two MCL injuries, two lateral meniscal differentiation of infantile tibia vara from physiologic tears, one medial meniscal tear, and one patellar tendon avul- bowing using the femoral-tibial ratio. J Pediatr Orthop sion. 2001;21:545-548. Shepley RW: Arthroscopic treatment of type III tibial A femoral-tibial ratio (FTR = femoral metaphyseal- spine fractures using absorbable fixation. Orthopedics diaphyseal angle/tibial metaphyseal-diaphyseal angle) of 0.7 or 2004;27:767-769. less or 1.4 or greater was associated with a less than 5% error risk. The FTR had a greater sensitivity and specificity versus Five patients (average age, 15 years) were treated with ab- the TMDA alone, with less rotational effect. sorbable polydioxanone pins for type III tibial spine fractures. 754 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 63 Knee and Leg: Pediatrics Blount’s Disease Grafting and intramedullary fixation was most successful when concomitant fibular surgery was performed (osteotomy Chotigavanichaya C, Salinas G, Green T, et al: Recur- or resection, with or without intramedullary fixation). Out- rence of varus deformity after proximal tibial osteotomy come did not correlate with the initial radiographic appear- in Blount disease: Long-term follow-up. J Pediatr Or- ance or age at surgery. Fibular involvement correlates with thop 2002;22:638-641. valgus deformity at the ankle. The recurrence rate in three groups was evaluated (pa- Kim HW, Weinstein SL: Intramedullary fixation and tient’s younger than 4 years [46%], patients older than 4 years bone grafting for congenital pseudarthrosis of the tibia. with crossed pins [94%], and patients older than 4 years with Clin Orthop 2002;405:250-257. external fixation [72%]). Early osteotomy and postoperative alignment in valgus decreased the risk of recurrence. Five of 12 pseudarthroses united after one procedure (three refractures), and 4 of the other 7 eventually healed with Craig JG, van Holsbeeck M, Zaltz I: The utility of MR multiple procedures. A poor prognosis was associated with dis- in assessing Blount disease. Skeletal Radiol 2002;31:208- tal pseudarthroses and concomitant pseudarthrosis of the fib- 213. ula. In patients with infantile Blount’s disease, ossification of Ng BK: Saleh M: Fibula pseudarthrosis revisited treat- the medial tibial epiphysis is delayed, and they may have wid- ment with Ilizarov apparatus: Case report and review of ening and depression of the medial physis, metaphyseal carti- the literature. J Pediatr Orthop B 2001;10:234-237. laginous intrusions, edema, lateral physeal widening, femoral Yang KY, Lee EH: Isolated congenital pseudarthrosis of osteochondral injury, hypertrophy of the medial meniscus, and the fibula. J Pediatr Orthop B 2002;11:298-301. focal physeal arrest. These two articles review four patients with the rare disor- Longitudinal Deficiency of the Fibula der of pseudarthrosis of the fibula. Treatment priorities are to restore union and to prevent or treat valgus at the ankle. Stanitski DF, Stanitski CL: Fibular hemimelia: A new classification system. J Pediatr Orthop 2003;23:30-34. Classic Bibliography This classification evaluates fibular morphology (I = nearly Achterman C, Kalamchi A: Congenital deficiency of the normal, II = small fibula, III = absent fibula), tibiotalar joint fibula. J Bone Joint Surg Br 1979;61:133-137. and distal tibial epiphyseal morphology (H = horizontal, V = valgus, S = spherical), the presence of a tarsal coalition, and the number of rays in the foot. Longitudinal Deficiency of the Tibia Anderson DJ, Schoeneker PL, Sheridan JJ, et al: Use of an intramedullary rod for the treatment of congenital Alekberov C, Shevtsov VI, Karatosun V, et al: Treatment pseudarthrosis of the tibia. J Bone Joint Surg Am 1992; of tibia vara by the Ilizarov method. Clin Orthop 2003; 74:161-168. 409:199-208. Feldman DS, Madan SS, Koval KJ, et al: Correction of Boyd HB: Pathology and natural history of congenital tibia vara with six-axis deformity analysis and the Taylor pseudarthrosis of the tibia. Clin Orthop 1982;166:5-13. spatial frame. J Pediatr Orthop 2003;23:387-391. Feldman MD, Schoenecker PL: Use of the metaphyseal- In these two studies the advantages of external fixation for diaphyseal angle in the evaluation of bowed legs. J Bone Joint Surg Am 1993;75:1602-1609. the treatment of infantile and adolescent Blount’s disease are Greene WB: Infantile Tibia Vara. J Bone Joint Surg Am shown in 91 patients. Multiplanar correction can be achieved 1993;75:130-143. gradually, and alignment can be adjusted based on standing ra- diographs. Limb-length discrepancy can be addressed simulta- neously. Tokmakova K, Riddle EC, Kumar SJ: Type IV congeni- Johnston CE II: Infantile Tibia Vara. Clin Orthop 1990; tal deficiency of the tibia. J Pediatr Orthop 2003;23:649- 255:13-23. 653. Jones D, Barnes J, Lloyd-Roberts GC: Congenital apla- Both reconstruction and amputation are considered for sia and dysplasia of the tibia with intact fibula: Classifi- this rare deformity, and patients with a functional (or recon- cation and management. J Bone Joint Surg Br 1978;60: structable) foot and a lesser degree of projected limb-length 31-39. discrepancy may benefit from reconstruction of the ankle mor- tise and subsequent limb lengthening. Kalamchi A, Dawe RV: Congenital deficiency of the tibia. J Bone Joint Surg Br 1985;67:581-584. Congenital Pseudarthrosis of the Tibia and/or Fibula Schoeneker PL, Capelli AM, Millar EA, et al: Congeni- Johnston CE II: Congenital pseudarthrosis of the tibia: tal longitudinal deficiency of the tibia. J Bone Joint Surg Results of technical variations in the Charnley-Williams Am 1989;71:278-287. procedure. J Bone Joint Surg Am 2002;84-A:1799-1810. American Academy of Orthopaedic Surgeons 755

Chapter 64 Ankle and Foot: Pediatrics Vincent S. Mosca, MD William Hennrikus, MD Clubfoot (Talipes Equinovarus) stress dorsiflexion AP and lateral views. There is no in- dication for routine radiographs or ultrasound imaging Idiopathic clubfoot occurs in approximately 1 of every of the child’s hips. 1,000 live births, affects males twice as often as females, and is bilateral in approximately 50% of cases. Recent The goal of treatment is a plantigrade foot with good genetic research supports the hypothesis of a multifacto- joint mobility that is functional, painless, stable over rial pattern of inheritance in which genetics plays a cen- time, and free of calluses. Initial treatment is nonsurgi- tral role. Environmental factors, such as maternal smok- cal. More than 50 years ago, Kite and Ponseti indepen- ing and amniocentesis in the first trimester, may dently proposed significantly different manipulation and modulate the genetic expression of the disorder. Club- casting techniques for clubfoot deformity correction foot can be identified on fetal ultrasound as early as the with each reporting extremely high success rates. For 12th week of gestation. The sensitivity and specificity unknown reasons, neither technique came into wide- are high, making prenatal counseling about treatment spread use and the past five decades have been marked and prognosis an appropriate and beneficial activity. by a proliferation of extensive and radical clubfoot sur- geries. Short- and intermediate-term follow-up studies The clubfoot is characterized by four basic deformi- on these radical surgical procedures revealed a high per- ties: (1) cavus (plantar flexion of the forefoot on the centage of painful, stiff, and deformed feet with the hindfoot, also described as pronation of the forefoot on need for additional surgery in 5% to 50% of cases. the hindfoot); (2) adductus of the forefoot on the mid- foot/hindfoot; (3) varus (or inversion) of the subtalar The Ponseti method has recently been reintroduced, joint complex; and (4) equinus of the foot at the ankle. based on scientific support of the efficacy of this These deformities are not passively correctable. There is method that was documented in a long-term follow-up a single (occasionally double) posterior ankle skin study that was published in 1995. That study showed lit- crease and a deep transverse skin crease across the mid- tle difference in appearance, comfort, and function in foot. In a clubfoot, the talus is smaller than normal, and 25- to 45-year-old patients with clubfoot who were the talar neck is deviated in a plantar medial direction. treated as infants, compared with age-matched controls. The axes of the anterior and middle facets of the calca- neus create a more acute angle than in the normal foot, With the Ponseti method, the clubfoot is manipu- with the anterior facet oriented inward. This creates a lated for 1 to 2 minutes before application of an above- corresponding varus deformity of the distal end of the knee cast. Cavus is corrected first, by dorsiflexing the calcaneus, resulting in a medial orientation of the calca- first metatarsal against a fulcrum that is the dorsolateral neocuboid joint. There also may be varying degrees of aspect of the head of the talus. In subsequent weekly medial subluxation at that joint. manipulations and above-knee cast applications, the ad- ductus and varus are corrected by abducting the fore- A complete physical examination of the child is indi- foot against the same fulcrum. Cavus, adductus, and cated to rule out a neurogenic or syndromic cause for varus are slightly overcorrected and the foot is exter- the deformity. There is no reported increased risk for nally rotated 60° to 70° in relation to the thigh after four developmental dysplasia of the hip in children with to seven casts have been worn. Percutaneous tenotomy clubfoot; however, examination of the hips in a newborn of the Achilles tendon is performed in approximately is always an important part of the musculoskeletal 90% of feet. The final above-knee cast is worn for 3 screening examination. The diagnosis of clubfoot in a weeks. The Achilles tendon reforms in a lengthened newborn can and should be based solely on clinical find- state during that time. Straight-last shoes externally ro- ings. If radiographs are obtained, either before, during, tated on an abduction bar are then worn full-time for 3 or after initiation of treatment, they should be taken as months and at night for up to 3 years. At least 95% of clubfoot deformities can be corrected without the need American Academy of Orthopaedic Surgeons 757

Ankle and Foot: Pediatrics Orthopaedic Knowledge Update 8 for extensive surgery if the treatment is begun soon af- the site of the deformity and is associated with few risks ter birth. To be successful, this method must be studied or complications. It may be necessary to perform a con- in detail, mastered, and should not be modified. current closing wedge osteotomy of the cuboid or os- teotomies at the base of the lesser metatarsals. Up to 40% of clubfeet will require lateral transfer of the tibialis anterior to the lateral cuneiform between the Congenital Vertical Talus ages of 2 and 5 years to correct a dynamic muscle imbal- ance (supination deformity) that is inherent in the club- Congential vertical talus is a dorsolateral dislocation of foot and not related to the initial method of deformity the talonavicular joint associated with extreme plantar correction. flexion of the talus. The foot has a rocker-bottom ap- pearance, and the head of the talus is prominent and Metatarsus Adductus palpable on the plantar-medial aspect of the midfoot. The hindfoot is plantar flexed. There is a dorsiflexion Metatarsus adductus is characterized by medial devia- contracture of the forefoot on the hindfoot that pre- tion of the forefoot on the midfoot with neutral or slight vents the creation of a longitudinal arch by passive ma- valgus alignment of the hindfoot. An important patho- nipulation. It is reported that the deformity occurs in as- genic factor may be a developmental abnormality that sociation with syndromes such as arthrogryposis, results in a trapezoid shape of the medial cuneiform myelomeningocele, and sacral agenesis in more than with medial orientation of the first metatarsal-medial 50% of patients. Congential vertical talus is bilateral in cuneiform joint. Metatarsus varus refers to a similar de- 50% of affected children. The primary differential diag- formity in which the metatarsals are adducted as well as nosis is positional calcaneovalgus deformity, a condition supinated. A skewfoot combines adduction and plantar that resolves completely in most patients. It is differenti- flexion of the forefoot, with moderate to severe valgus ated clinically by flexibility of the midfoot but a dorsi- deformity of the hindfoot. The literature is inconsistent flexion contracture of the ankle joint. A lateral radio- with these definitions. graph of a congenital vertical talus in maximum dorsiflexion shows fixed plantar flexion of the talus. A Metatarsus adductus can be classified according to lateral radiograph in maximum plantar flexion shows an the degree of deformity as mild, moderate, or severe us- irreducible dislocation of the talonavicular joint and ing the heel bisector line. A second classification system, confirms the diagnosis. based on flexibility, is prognostic. Flexible metatarsus adductus deformities can be easily abducted beyond Surgery is required for deformity correction in straight alignment. Partly flexible metatarsus adductus nearly all feet with congenital vertical talus. Preliminary deformities correct to a straight foot alignment with serial plantar flexion casting is used to stretch the dorsal passive abduction, and rigid feet do not straighten man- tendons, skin, and neurovascular structures of the foot. ually. Flexible metatarsus adductus, which accounts for Reduction of the talonavicular joint dislocation is de- 90% to 95% of all deformities, corrects spontaneously sired, but rarely achieved with casting. in the first 3 to 5 years of life. Partly flexible and rigid feet benefit from serial manipulation and casting in in- In the past, treatment has been surgical reconstruc- fants younger than 1 year of age. The lateral pressure tion between ages 6 and 18 months using a single stage point is at the calcaneocuboid joint, not the head of the circumferential release. Surgical reconstruction through talus as in clubfoot casting. The subtalar joint is held in a dorsal approach to the talonavicular joint, with con- slight inversion and the ankle in slight plantar flexion to current Achilles tendon lengthening, has more recently prevent inadvertent eversion of the subtalar joint. Three been shown to result in excellent and lasting deformity to four weekly manipulations and long leg cast applica- correction, with less scar formation and shorter surgical tions are needed to slightly overcorrect the deformity. A time. Naviculectomy, by shortening the elongated me- holding device, such as a reverse or straight-last shoe, dial column of the foot, is an effective surgery for cor- should be used for several months thereafter to prevent recting recurrent or untreated congenital vertical talus recurrence of deformity. Good results can be expected deformity in the older child. This procedure preserves at long-term follow-up without a need for surgery, even some motion in the resultant pseudo-subtalar joint com- when there is mild to moderate residual deformity. Se- plex. Subtalar and triple arthrodeses have also been rec- vere, rigid deformity in the older child may cause pain, ommended in the older age group, but it is technically callus formation, and shoe-fitting problems for which challenging to correct severe valgus deformity of the surgery would be indicated. hindfoot with either procedure, and these surgeries lead to stress transfer to adjacent joints. Subtalar arthrodesis Tarsometatarsal capsulotomies and osteotomies at has also been associated with progressive overcorrection the base of the metatarsals are associated with signifi- of the deformity in some feet. cant complications. An opening wedge osteotomy of the trapezoid-shaped medial cuneiform offers treatment at 758 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 64 Ankle and Foot: Pediatrics Tarsal Coalition coalitions have been good, but the results deteriorate rapidly with time and long-term studies are not avail- Tarsal coalition is a fibrous, cartilaginous, or bony con- able. Unsatisfactory results with resection have been re- nection between two or more tarsal bones that results ported in feet in which the ratio of the surface area of from a congenital failure of differentiation and segmen- the coalition to the surface area of the posterior facet tation of primitive mesenchyme. It affects at least 1% to was greater than 50% (as determined by CT scan) and 2% of the general population and is most commonly in which there was significant valgus deformity of the seen as an autosomal dominant condition with nearly hindfoot and narrowing of the posterior facet. The inde- full penetrance. Talocalcaneal and calcaneonavicular co- pendent influence of the size of the coalition was not alitions occur with about equal frequency, are usually bi- determined in that or any other study. Some authors lateral, and together account for nearly all coalitions. recommend resection of a symptomatic talocalcaneal There may be more than one tarsal coalition in the coalition regardless of its size if the foot is not fixed in same foot. severe valgus alignment. The presence of a talar beak does not necessarily indicate the presence of degenera- Maturation of the coalition coincides with the devel- tive arthrosis and is not, by itself, a contraindication for opment of progressive valgus deformity of the hindfoot resection. Documented degenerative arthrosis and per- and restriction of subtalar motion, all of which are more sistence or recurrence of pain following coalition resec- severe in a foot with a talocalcaneal coalition. For an in- tion are considered by some to be indications for triple dividual with a tarsal coalition who develops pain, the arthrodesis, though supportive data are lacking. Severe onset of symptoms may coincide with bony transforma- symptomatic valgus deformity of the hindfoot associ- tion of a previously cartilaginous coalition. This gener- ated with a talocalcaneal coalition can be corrected and ally occurs between 8 and 12 years of age for those chil- pain relieved with a calcaneal osteotomy with or with- dren with calcaneonavicular coalitions, and between 12 out concurrent resection of the coalition. and 16 years of age for those with talocalcaneal coali- tions. The onset of vague, aching, activity-related pain in Fractures the sinus tarsi area or along the medial aspect of the hindfoot is often insidious. The peroneal tendons appear Intra-articular ankle fractures are uncommon but prob- to be in spasm and can develop a late contracture. The lematic in children. Four general fracture types are me- exact etiology and the anatomic location of the pain and dial malleolar fractures, Tillaux fractures, triplane frac- spasm are debated. Examination of the foot reveals tures, and pilon fractures. Controversial aspects in the stiffness or rigidity of an everted subtalar joint. The treatment of these injuries include the indications for a hindfoot remains in valgus alignment even with toe CT scan and how much displacement indicates reduc- standing. tion and fixation. Complications stemming from these injuries center on growth arrest and articular incongru- Calcaneonavicular coalitions are best seen on an ob- ity. lique radiograph of the foot. Talocalcaneal coalitions are best seen on coronal plane images of a CT scan. A CT Medial malleolar fractures occur in young children scan should be obtained for feet with calcaneonavicular with an average age of injury of 8 years. The mechanism coalitions because a talocalcaneal coalition may coexist. of injury is supination and inversion of the foot resulting MRI is helpful in identifying coalitions that are still in in a Salter-Harris type III or IV injury. Three radio- the fibrous stage and not visualized on radiographs or graphic views of the ankle are recommended: AP (Fig- CT scans, but this should not be a first-line study. A ure 1), lateral, and oblique. CT is not needed in most in- bone scan can be helpful in identifying other possible stances. Any displacement of a physeal fracture of the etiologies for a rigid flatfoot with an atypical presenta- medial malleolus requires reduction and possible fixa- tion of pain (osteoid osteoma, infection, fracture). tion. These injuries occur in younger children with many years of growth remaining; therefore, anatomic reduc- Treatment is indicated for symptomatic tarsal coali- tion is needed to minimize angular deformity and short- tions. Nonsurgical treatment such as cast immobiliza- ening. Treatment strategies involve closed reduction and tion, soft orthotic devices, and anti-inflammatory medi- pinning or cannulated screw fixation. If open reduction cations should be used initially. Surgical treatment is and internal fixation is needed, minimal stripping of the indicated if pain recurs after initially successful nonsur- periosteum is recommended to prevent iatrogenic gical treatment. Good long-term pain relief can be ex- growth arrest (Figure 2). When treating a Salter-Harris pected in most patients after resection of calcaneonavic- type IV injury, the Thurston-Holland fragment can be ular coalitions with interposition of the extensor safely removed to visualize the physis. Visualization of digitorum brevis. An osteologic study has shown at least the joint can be accomplished by a small anterior ar- three anatomic variations for calcaneonavicular coali- throtomy. Fixation should be performed parallel to tions. Poor results may correlate with the exact patho- rather than across the physis. Screws provide compres- logic anatomy of the coalition. The short-term results of resection and soft-tissue interposition for talocalcaneal American Academy of Orthopaedic Surgeons 759

Ankle and Foot: Pediatrics Orthopaedic Knowledge Update 8 Figure 1 AP radiograph of the ankle showing a displaced medial malleolar physeal Figure 2 AP radiograph following closed reduction of the fibular fracture and open fracture and a displaced distal fibular physeal fracture. reduction and internal fixation of the medial malleolar fracture. sion and may therefore be superior to Kirschner wires. (Figure 3). Treatment strategies include attempted Osteotomy and physeal bar resection may be needed if closed reduction by internal rotation, supination, and di- growth arrest occurs. Long-term follow-up shows that rect pressure; percutaneous manipulation with a Stein- osteoarthritis results in about 10% of these injuries. mann pin; and open reduction and internal fixation us- ing a small anterior arthrotomy. Compression screw Tillaux fractures occur in older children (average fixation can cross the physis because the remaining age, 13 years). The mechanism of injury is supination growth potential is minimal. Long-term follow-up stud- and external rotation resulting in the avulsion of the ies are needed. anterior-lateral distal tibial physis by the pull of the anterior-inferior tibia-fibula ligament. The maturing dis- Triplane fractures occur in children nearing skeletal tal tibial physis closes centrally, then medially, then lat- maturity (average age, 14 years). The mechanism of in- erally. The open lateral physis is vulnerable to injury in jury is supination and external rotation. The number of this age group. Three radiographic views are needed. In fracture fragments depends on which part of the physis one third of patients, the Tillaux fracture is only seen on is closed at the time of injury. The fracture occurs in the oblique view. The articular surface displacement three planes: the coronal plane—the lateral radiograph needs to be reduced to less than 2 mm to minimize the shows a Salter-Harris type II fracture; transverse development of osteoarthritis. Articular congruity is the plane—epiphysiolysis through the anterior and lateral major concern; physeal arrest is not a concern because physis; or sagittal plane—the AP radiograph typically the patient is close to skeletal maturity. CT is commonly shows a Salter-Harris type III fracture. The extent of the used and appears to be better than radiographs in deter- injury is often underappreciated on plain films; there- mining if the fracture is displaced greater than 2 mm fore, CT is recommended in most cases. CT defines the 760 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 64 Ankle and Foot: Pediatrics the two most common reasons for a patient with a plan- tar puncture wound to be referred for orthopaedic care. Pseudomonas septic arthritis or osteomyelitis should be suspected in any patient with swelling and foot pain that occurs after stepping on a nail while wearing a sneaker. Pseudomonas bacteria commonly grow in the foam rub- ber in the sole of the sneaker. Pseudomonas have an af- finity to invade the cartilaginous joint surfaces and phy- ses. Therefore, in infection stemming from a nail puncture wound through a sneaker, open surgical débride- ment and a course of intravenous antibiotics are recom- mended. Consultation with an infectious disease special- ist should be considered in problematic cases. In patients with suspected retained foreign bodies, radio- graphs are indicated to detect radiodense objects such as needle fragments and some types of glass; ultrasound can be used to detect radiolucent glass fragments, tooth- picks, and splinters. Not all patients require wound ex- ploration and a search for a foreign body. A 3-week pe- riod of short leg casting results in the extrusion of radiolucent foreign bodies in some instances. Wound ex- ploration, when deemed necessary, is best done in the operating theater with adequate anesthesia, magnifica- tion, and fluoroscopy. A tetanus update is recommended for any patient with a plantar puncture wound. Figure 3 Reformatted CT showing the extent of displacement of a Tillaux fracture. Apophysitis/Osteochondrosis number of fracture fragments, defines the displacement, Sever’s disease (apophysitis of the calcaneus) is a com- and helps in planning surgical incisions. Articular con- mon cause of heel pain in the child and adolescent. gruity, not physeal arrest, is the major concern with Kohler’s disease and Freiberg’s infraction are less com- triplane fractures because the patient has almost mon causes of midfoot pain and metatarsal pain in this reached skeletal maturity. The goal of treatment is to re- age group. store the articular displacement to less than 2 mm to minimize long-term osteoarthritis. Treatment strategies Sever’s Disease include closed reduction, closed reduction and fixation, and open reduction and internal fixation. Fixation can Sever’s disease is a traction apophysitis at the insertion cross the physis, and screws are recommended to pro- of the Achilles tendon. The patient reports heel pain vide compression. The 2-mm limit of displacement may that worsens during participation in running sports. not be the only factor in long-term outcome. Injury to Physical examination shows tenderness at the insertion the distal tibiofibular joint and damage to the articular of the Achilles tendon on the calcaneus. In addition, cartilage at the time of injury may lead to long-term most patients have decreased ankle dorsiflexion com- symptoms despite an adequate reduction. Pilon frac- pared with the uninvolved side and pain with forced tures are discussed in chapter 39. dorsiflexion of the ankle. The pain associated with Sev- er’s disease increases with activity and decreases with Puncture Wounds rest. Radiographs are normal and rule out conditions such as calcaneal bone cyst or calcaneal stress fracture Most puncture wounds of the foot are treated by emer- that can have similar symptoms. gency department and primary care physicians and do not require orthopaedic care. One study defined the Symptomatic treatment consisting of rest, Achilles natural history of plantar puncture wounds by following tendon stretching, ice, nonsteroidal anti-inflammatory 63 patients prospectively. Treatment in the emergency drugs, and modification of running activity is recom- department included surface cleaning alone. Five infec- mended. In addition, a 1-cm heel cushion may be help- tions (8%) and two retained foreign bodies (3%) oc- ful to decrease traction on the apophysis and reduce curred. An infection and/or a retained foreign body are symptoms. If the pain persists despite the previously outlined treatment, immobilization in a short leg walk- ing cast for 1 to 2 months is recommended. Unfortu- nately, an undulating course with possible recurrences of American Academy of Orthopaedic Surgeons 761

Ankle and Foot: Pediatrics Orthopaedic Knowledge Update 8 pain is common, and patient education about the natu- osteotomy or shortening osteotomy. Metatarsal head re- ral history of Sever’s disease is key. The problem abates section is not recommended because this procedure may at skeletal maturity when the apophysis closes. No long- transfer pressure and pain to an adjacent metatarsal term complications have been reported. head. Kohler’s Disease Adolescent Bunion Kohler’s disease is osteonecrosis of the tarsal navicular. Adolescent bunion is a prominence of the medial aspect Radiographs show flattening sclerosis and irregularities. of the first metatarsal head associated with a valgus de- The disorder is more common in boys and is bilateral in formity of the hallux. Weight-bearing AP and lateral ra- about 20% of patients. It is believed that Kohler’s dis- diographs of the feet confirm the clinical diagnosis. Nor- ease stems from repetitive microtrauma to the midfoot mal radiographic angles between the first and second with weight bearing. A possible genetic predisposition metatarsals (intermetatarsal angle) are from 6° to 10° has been suggested. The patient with Kohler’s disease and between the first metatarsal and the proximal pha- limps and bears weight on the lateral side of the foot. lanx (hallux valgus angle) are from 10° to 20°. A bunion Physical examination shows tenderness and occasional in an adolescent is present if the intermetatarsal angle swelling at the medial midfoot. Treatment consists of exceeds 10° and the hallux valgus angle exceeds 20°. The foot support. Rest combined with a soft arch support is etiology of adolescent bunion is multifactorial. The pa- recommended for mild symptoms. A short leg walking tient usually comes for treatment because of the cos- cast for 1 to 2 months followed by a soft arch support is metic deformity and is rarely symptomatic. Physical ex- recommended for more severe symptoms. Casting ap- amination shows abnormal angulation and mobility of pears to hasten the resolution of symptoms compared the first metatarsocuneiform joint, medial deviation of with orthotic devices alone. However, the duration of the first metatarsal, and a congruous first metatarsopha- time for radiographic bone restoration averages langeal joint. The results of surgery in an adolescent 8 months despite the treatment selected. Clinical defor- with a bunion are unpredictable with a 50% recurrence mity such as flatfoot does not occur. rate. Associated pes planus, a tight Achilles tendon, and a long great toe result in the highest recurrence rate. Freiberg’s Infraction Therefore, surgery should be delayed until skeletal ma- turity if possible. Suggested treatment options until the Freiberg’s infraction is osteonecrosis of one of the meta- patient reaches skeletal maturity include a shoe with a tarsal heads. The etiology may involve repetitive mi- wide, rounded toe box, a total contact insole with a crotrauma disrupting the blood supply. The condition fixed toe separator, and daily exercises combined with a occurs most often in adolescent female athletes. The nighttime thermoplastic splint. Surgery may be consid- longest metatarsal, usually the second, is typically af- ered in patients who have exhausted nonsurgical treat- fected. Radiographs show metatarsal head irregularity, ment options and still experience pain that interferes enlargement, flattening, and sclerosis. In patients with with normal activities. No single surgical technique is advanced etiology, joint space narrowing and osteochon- applicable in all patients. Proximal metatarsal osteot- dritis dissecans may develop. Patients with Freiberg’s in- omy should be used with caution if the proximal physis fraction report forefoot pain. Physical examination is open; otherwise, growth arrest and shortening may oc- shows local swelling and tenderness over the metatarsal cur. Shortening can result in transfer metatarsalgia. head with occasional stiffness of the metatarsopha- langeal joint. Most patients can be treated symptomati- Annotated Bibliography cally with activity modification, nonsteroidal anti- inflammatory drugs, a metatarsal bar shoe insert, or a Clubfoot (Talipes Equinovarus) change in shoe wear to relieve the weight-bearing stress on the involved metatarsal head. A short leg walking Dietz F: The genetics of idiopathic clubfoot. Clin Orthop cast followed by a metatarsal bar is sometimes required 2002;401:39-48. for more severe cases. Usually, the disease runs its course and the metatarsal head reconstitutes in about 2 An excellent and comprehensive review of this important years. In the minority of patients in whom conservative aspect of clubfoot is presented. care is unsuccessful, surgery is indicated. Surgery should be performed with caution because the reported series Herzenberg JE, Radler C, Bor N: Ponseti versus tradi- are small and without comparison groups. Surgical op- tional methods of casting for idiopathic clubfoot. tions include metatarsophalangeal arthrotomy and re- J Pediatr Orthop 2002;22:517-521. moval of loose bodies, drilling the metatarsal head, sub- chondral bone grafting, interposition arthroplasty using This is the first report from outside of Iowa comparing the the extensor digitorum longus tendon, and dorsiflexion Ponseti method for clubfoot deformity correction with tradi- tional casting followed by extensive posteromedial release sur- gery. The authors’ results with 34 clubfeet treated with the Ponseti method matched the results reported by Ponseti de- 762 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 64 Ankle and Foot: Pediatrics cades ago and recently, and revealed superiority over the tra- tational weeks/day). The authors hypothesize that decreased ditional method. amniotic fluid in the early group, during the time of maximum foot growth velocity, leads to decreased fetal movement result- Ippolito E, Farsetti P, Caterini R, Tudisco C: Long-term ing in joint and limb deformities. comparative results in patients with congenital clubfoot treated with two different protocols. J Bone Joint Surg Congenital Vertical Talus Am 2003;85-A:1286-1294. Mazzocca AD, Thomson JD, Deluca PA, Romness MJ: Forty-seven clubfeet treated with extensive posteromedial Comparison of the posterior approach versus the dorsal release (after an average of 16 abduction/pronation casts) approach in the treatment on congenital vertical talus. were compared with 49 clubfeet treated with an open Achilles J Pediatr Orthop 2001;21:212-217. Z-lengthening and posterior ankle capsulotomy (after an aver- age of six Ponseti-type supination/abduction casts). Follow-up Twenty-five consecutive congenital vertical tali that were at 25 years for group one and 19 years for group two showed treated with a traditional posterior release operation (average significantly better results in the second group, although not as age, 18 months; range, 6 to 67 months) were compared with good as the results reported by Cooper and Dietz using the eight consecutive feet treated with deformity correction via traditional Ponseti technique with percutaneous Achilles tenot- the dorsal approach (average age, 26.5 months; range, 6 to 65 omy. The authors recommend treating clubfeet according to months). The dorsal approach group required 30% less surgi- the method of Ponseti. cal time, had better clinical scores, and fewer complications in- cluding no recurrences (versus 32%) and no cases of osteone- crosis of the talus (versus 48%). Kuo KN, Hennigan SP, Hastings ME: Anterior tibial ten- Tarsal Coalition don transfer in residual dynamic clubfoot deformity. J Pediatr Orthop 2001;21:35-41. Cooperman DR, Janke BE, Gilmore A, Latimer BM, Brinker MR, Thompson GH: A three-dimensional study Forty-two full anterior tibial tendon transfers to the lateral of calcaneonavicular tarsal coalitions. J Pediatr Orthop cuneiform were compared with 29 split anterior tibial tendon 2001;21:648-651. transfers to the cuboid as treatment of dynamic supination de- formity of previously operated clubfeet. There was no signifi- Thirty-seven presumed calcaneonavicular tarsal coalitions cant difference in results between the two techniques. from the Todd Osteological Collection in Cleveland were stud- ied. The anterior facet of the calcaneus was completely spared Pirani S, Zeznik L, Hodges D: Magnetic resonance im- by the coalition in 8 specimens, partially replaced by the navic- aging study of the congenital clubfoot treated with the ular portion of the coalition in 7, and completely replaced by Ponseti method. J Pediatr Orthop 2001;21:719-726. the navicular portion of the coalition in 22. It is hypothesized that this variable coalition anatomy is a potential cause for MRI was performed on infant clubfeet undergoing manip- poor results after resection, particularly if the resection creates ulation and cast treatment according to the Ponseti method at joint instability. the beginning, middle, and end of treatment. Correction of ab- normal relationships between tarsal bones was documented. Fractures Additionally, the abnormal shapes of the individual tarsal os- teochondral anlages were corrected. This effect can be ac- Barmada A, Gaynor T, Mubarak SJ: Premature physeal counted for by changes in mechanical loading of these fast- closure following distal tibia physeal fractures. J Pediatr growing tissues. Orthop 2003;23:733-739. Skelly AC, Holt VL, Mosca VS, Alderman BW: Talipes A residual physeal gap of more than 3 mm following treat- equinovarus and maternal smoking: A population-based ment of a distal tibial physeal fracture was associated with case-control study in Washington state. Teratology 2002; high rates of premature physeal closure. The authors suggest 66:91-100. that open reduction and removal of entrapped periosteum may be beneficial. This article presents an epidemiology study showing an in- creased risk of having a child with clubfoot if the mother Horn BD, Crisci K, Krug M, et al: Radiologic evaluation smoked during pregnancy. There was a dose response with in- of juvenile Tillaux fractures of the distal tibia. J Pediatr creased risk correlated with the number of cigarettes smoked. Orthop 2001;21:162-164. Tredwell SJ, Wilson D, Wilmink MA, et al: Review of the CT is the preferred imaging modality for detecting more effect of early amniocentesis on foot deformity in the than 2 mm of displacement in juvenile Tillaux fractures. neonate. J Pediatr Orthop 2001;21:636-641. Leetum DT, Ireland ML: Arthroscopically assisted re- Clubfoot was identified in 1.63% of live births in mothers duction and fixation of a juvenile Tillaux fracture. who had undergone early amniocentesis (11 to approximately Arthroscopy 2002;18:427-429. 12 gestational weeks/day) versus 0.12% in those who under- went midtrimester amniocentesis (15 to approximately 16 ges- Arthroscopic visualization assisted with the anatomic re- duction of the articular fragment, obviating the need for ankle arthrotomy, is discussed. American Academy of Orthopaedic Surgeons 763

Ankle and Foot: Pediatrics Orthopaedic Knowledge Update 8 Leets M, Davidson D, McCaffrey M: The adolescent pi- Clark M, D’Ambrosia R, Ferguson A: Congenital verti- lon fracture: management and outcome. J Pediatr cal talus: Treatment by open reduction and navicular ex- Orthop 2001;21:20-26. cision. J Bone Joint Surg Am 1977;59:816-824. Pilon fractures in adolescents result from high-energy Cooper D, Dietz F: Treatment of idiopathic clubfoot: A trauma and are associated with a high complication rate. Re- thirty-year follow-up note. J Bone Joint Surg Am 1995; sults were good to excellent in only 63% of cases. The authors 77:1477-1489. suggest a new classification system for adolescent pilon frac- tures. Coughlin MJ, Bordelon RL, Johnson KA, et al: Evalua- tion and treatment of juvenile hallux valgus. Contemp Marsh JL, Buckwalter J, Gelberman R, et al: Articular Orthop 1990;21:169-203. fractures: does anatomic reduction really change the re- sult? J Bone Joint Surg Am 2002;84-A:1259-1271. Duncan RD, Fixsen JA: Congenital convex pes valgus. J Bone Joint Surg Br 1999;81:250-254. The authors suggest that there is no convincing evidence that improved articular reduction leads to a better outcome or Ezra E, Hayek S, Gilai AN, Khermosh O, Wientroub S: a lower risk of osteoarthritis. Rather, the authors suggest that Tibialis anterior tendon transfer for residual dynamic damage to the articular cartilage at the time of injury is the supination deformity in treated clubfeet. J Pediatr Or- most important factor in outcome. thop B 2000;9:207-211. Seifert J, Matthes G, Hinz P, et al: Role of MRI in the di- Farsetti P, Weinstein SL, Ponseti IV: The long-term func- agnosis of distal tibia fractures in adolescents. J Pediatr tional and radiographic outcomes of untreated and non- Orthop 2003;23:727-732. operatively treated metatarsus adductus. J Bone Joint Surg Am 1994;76:257-265. The authors report that MRI provided anatomic detail and information about the joint surfaces superior to plain film ra- Freiberg AH: The so-called infarction of the second diographs. metatarsal bone. J Bone Joint Surg 1926;8:257. Apophysitis/Osteochondrosis Grosoia JA: Juvenile hallux valgus: A conservative ap- proach to treatment. J Bone Joint Surg Am 1992;74: Tang SF, Chen CP, Pan JL, et al: The effects of a new 1367-1374. foot-toe orthosis in treating painful hallux valgus. Arch Phys Med Rehabil 2002;83:1792-1795. Honein MA, Paulozzi LJ, Moore CA: Family history, maternal smoking, and clubfoot: An indication of a The authors report that using a total contact insole with a gene-environment interaction. Am J Epidemiol 2000; fixed toe separator reduced pain and improved the hallux val- 152:658-665. gus angle without causing skin ulcers or blisters. Huurman WW, Bhuller GS: Nonoperative treatment of Tsirikos AI, Riddle EC, Kruse R: Bilateral Kohler’s dis- retained radio lucent foreign bodies in lower limbs. ease in identical twins. Clin Orthop 2003;409:195-198. J Pediatr Orthop 1982;2:506-508. Bilateral Kohler’s disease in identical twins suggests that a Ippolitoo E, Ricciardi Pollini PT, Falez F: Kohler’s dis- genetic predisposition to the disorder may exist. ease of the tarsal navicular: Long-term follow up of 12 cases. J Pediatr Orthop 1984;4:416-417. Volpon JB, de Carvalo Filho G: Calcaneal apophysitis: A quantitative radiographic evaluation of the secondary Katcherian DA: Treatment of Freiberg’s disease. Orthop ossification center. Arch Orthop Trauma Surg 2002;122: Clin North Am 1994;25:69-81. 338-341. Kling TF, Bright RW, Hensinger RN: Distal tibial phy- A radiographic study of patients with Sever’s disease com- seal fractures in children that may require open reduc- pared with normal control patients is presented. The sclerotic tion. J Bone Joint Surg Am 1984;66:647-657. aspect of the calcaneus apophysis is a normal finding and should not be used to establish the diagnosis of Sever’s dis- Kumar S, Guille J, Lee M, Couto J: Osseous and non- ease. osseous coalition of the middle facet of the talocalca- neal joint. J Bone Joint Surg Am 1992;74:529-535. Classic Bibliography Laaveg S, Ponseti I: Long-term results of treatment of Bleck E: Metatarsus adductus: Classification and rela- congenital club foot. J Bone Joint Surg Am 1980;62:23- tionship to outcomes of treatment. J Pediatr Orthop 31. 1983;3:2-9. Caterini R, Farsetti P, Ippolitio E: Long term follow up of physeal injury to the ankle. Foot Ankle 1991;11:372- 383. 764 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 64 Ankle and Foot: Pediatrics Leonard MA: The inheritance of tarsal coalition and its Rebbeck T, Dietz F, Murray J, Buetow K: A single-gene relationship to spastic flat foot. J Bone Joint Surg Br explanation for the probability of having idiopathic tal- 1974;56:520-526. ipes equinovarus. Am J Hum Genet 1993;53:1051-1063. McHale KA, Lenhart MK: Treatment of residual club- Schwab RA, Powers RD: Conservative therapy for plan- foot deformity, the “bean-shaped” foot, by open wedge tar puncture wounds. J Emerg Med 1995;13:291-295. medial cuneiform osteotomy and closing wedge cuboid osteotomy: Clinical review and cadaver correlations. Seimon L: Surgical correction of congenital vertical ta- J Pediatr Orthop 1991;11:374-381. lus under the age of 2 years. J Pediatr Orthop 1987;7: 405-411. Micheli LJ, Ireland ML: Prevention and management of calcaneal apophysitis in children: An overuse syndrome. Sever JW: Apophysitis of the os calcis. NY Med J J Pediatr Orthop 1987;7:34-38. 1912;95:1025. Pennycook A, Makaower R, O’Donnell AM: Puncture Wilde P, Torode I, Dickens D, Cole W: Resection for wounds of the foot: Can infective complications be symptomatic talocalcaneal coalition. J Bone Joint Surg avoided? J R Soc Med 1994;87:581-583. Br 1994;76:797-801. Ponseti I: Congenital Clubfoot. Oxford, England, Oxford Williams GA, Cowell HR: Kohler’s disease of the tarsal University Press, 1996. navicular. Clin Orthop 1981;158:53-58. Ponseti IV, Becker JR: Congenital metatarsus adductus: The results of treatment. J Bone Joint Surg Am 1966;48: 702-711. American Academy of Orthopaedic Surgeons 765



Chapter 65 Pediatric Spine Trauma William C. Warner, Jr, MD Gregory A. Mencio, MD Introduction tent tenderness, paraspinal muscle spasms, limitation of motion, or persistent torticollis should alert the exam- Cervical spine injuries are uncommon in children and iner to a possible cervical spine injury. An adequate usually are associated with motor vehicle crashes, neurologic examination is difficult in a frightened child, pedestrian-vehicle accidents, or falls in young children. and frequent examinations may be required to reliably In older children, sports injuries, diving accidents, and determine neurologic status. gunshot injuries are the most common causes. An awareness of the unique aspects of the pediatric cervical Initial radiographs should include cross-table lateral, spine and an understanding of its growth and develop- AP, and odontoid open-mouth views. It is mandatory that ment are necessary for correct diagnosis and proper the cervicothoracic junction be visible on the plain radio- treatment. Normal physes may be mistaken for frac- graphs. On the lateral radiographs, four lines should be tures, resulting in overtreatment, and certain fractures drawn corresponding to the anterior vertebral bodies, the that occur through open physes may be undertreated. posterior vertebral bodies, the inside of the lamina (spino- laminar line), and the tips of the spinous processes (Fig- The atlas develops from three ossification centers ure 2). All four of these lines should follow a smooth, even (Figure 1). The posterior arches fuse by 3 to 4 years of contour.The articular facets should be parallel and the in- age, and the neurocentral synchondrosis between the lat- terspinous ligaments balanced.The retropharyngeal space eral masses and the body fuse at approximately 7 years should be less than 7 mm, and the retrotracheal space of age. The odontoid process is separated from the body should be less than 14 mm in children.An atlanto-dens in- of the axis by a synchondrosis, which usually is fused by terval of 4 to 5 mm is normal in young children; in adults 6 to 7 years of age. This synchondrosis appears as a “cork and adolescents, this interval should be 3 mm.The atlanto- in a bottle” on an open mouth odontoid radiograph. The dens interval is increased in young children because a sig- lower cervical vertebrae also are composed of three pri- nificant portion of the dens is cartilaginous and not visi- mary ossification centers, one for the body and two for ble on plain radiographs. This situation also gives the the neural arches. The neural arches fuse posteriorly by appearance of overriding of the atlas on the unossified od- 3 years of age, and the neurocentral synchondrosis fuses ontoid on extension lateral radiographic views. Oblique with the body between 3 and 6 years of age. The verte- radiographs show details of the facet joints and pedicles bral bodies are wedge-shaped until 7 years of age, and and are useful for determining if a fracture or fracture- then gradually become rectangular. dislocation is present. Flexion and extension radiographs should be obtained only in an awake and cooperative Upper cervical spine injuries are more common in child under the supervision of a physician; these radio- children between birth and 8 years of age. After 8 years graphs may be inappropriate in a very young child or an of age, the injury patterns become more like those in obtunded patient. Because of the increased physiologic adults, with the lower cervical spine more frequently in- motion in young children, pseudosubluxation of the sec- volved. Factors contributing to the increased frequency ond cervical vertebra on the third or the third cervical ver- of upper cervical spine injuries in the young child in- tebra on the fourth may be present, most commonly in clude the relatively horizontal facets, the large head size children 1 to 7 years of age. Swischuk’s line is helpful in relative to trunk size, muscle weakness, and the in- differentiating this phenomenon from true injury.This line creased physiologic motion of the neck in children. is drawn along the posterior arch (spinolaminar line) of C1 to C3 and should pass within 1.5 mm of the posterior In young children, diagnosis of a cervical spine in- arch of C2 (Figure 3). jury may be difficult; repeated examinations and a high index of suspicion often are needed. Upper cervical CT scans with three-dimensional reconstruction views spine injuries are frequent in young children with facial may be helpful in identifying fractures of the upper cer- trauma (fractures) and head trauma. Any pain or persis- American Academy of Orthopaedic Surgeons 767

Pediatric Spine Trauma Orthopaedic Knowledge Update 8 Figure 1 A, Ossification centers of the atlas. B, Ossification centers for the axis. (Reproduced from Copley LA, Dormans JP: Cervical spine disorders in infants and children. J Am Acad Orthop Surg 1998;6:205.) vical spine (base of the skull, C1 or C2 vertebra) and in Figure 2 Normal relationships in the lateral aspect of the cervical spine. 1 = spinous evaluating atlantoaxial rotatory subluxation. MRI is espe- processes, 2 = spinolaminar line, 3 = posterior vertebral body line, and 4 = anterior cially useful for ruling out cervical spine injuries in pa- vertebral body line. (Reproduced from Copley LA, Dormans JP: Cervical spine disor- tients who are obtunded or have a closed head injury and ders in infants and children. J Am Acad Orthop Surg 1998; 6:205.) may be difficult to evaluate because of their associated in- juries. In a recent study, MRI was able to “clear” the cer- and increased awareness of this injury, more children vical spine in intubated, obtunded, and uncooperative are surviving atlanto-occipital dislocations. Dislocation children with suspected cervical spine injuries. MRI also of the atlanto-occipital joint is caused by a sudden de- was useful in documenting or ruling out injuries suggested celeration injury, such as a motor vehicle or pedestrian- by plain radiographs and CT scans. MRI confirmed the vehicle accident. The child’s head is thrown forward on plain radiography diagnosis in 66% of patients and altered the relatively fixed trunk, causing sudden cranioverte- the diagnosis in 34%. bral separation. Because the atlanto-occipital joint has little inherent bony stability and most of its stability is Adequate immobilization of the cervical spine is dif- provided by its ligamentous attachments, most atlanto- ficult in children. Because commercial cervical collars of- occipital dislocations are unstable and require surgical ten do not fit properly, they do not provide adequate im- stabilization. The diagnosis of this condition may be dif- mobilization. Sandbags can be placed on each side of the ficult but is suggested by the mechanism of injury and head to prevent motion. Spine boards used for children the significant amount of anterior soft-tissue swelling should be modified to accommodate the large size of the visible on lateral radiographs. head in relationship to the trunk. An occipital recess or a split mattress technique should be used to prevent un- The three most reliable radiographic findings to as- wanted flexion of the cervical spine (Figure 4). A halo ring sist in the diagnosis of atlanto-occipital dislocation are and vest can be used for immobilization of the cervical (1) the Wackenheim line, (2) the Powers ratio, and (3) spine in children, but an increased complication rate has the occipital condylar distance. The Wackenheim line is been reported in children compared with adults. CT scan- drawn along the clivus and should intersect tangentially ning can help in pin placement to avoid cranial sutures the tip of the odontoid (Figure 5). An anterior or poste- and thin areas of the skull. Eight to 12 pins with low in- rior shift of this line indicates an anterior or posterior sertional torques of 1 to 5 inch-lb are used in children.The displacement of the occiput on the atlas. The Powers ra- vest often must be custom fitted to avoid motion in the tio is determined by drawing a line from the basion to vest portion while the head is fixed in the halo portion of the posterior arch of the atlas and a second line from the orthosis. the opisthion to the anterior arch of the atlas (Figure 6). A ratio of more than 1.0 or less than 0.55 represents a Specific Cervical Spine Injuries Atlanto-Occipital Dislocation In the past, atlanto-occipital dislocation usually was a fatal injury, but with current emergency medical care 768 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 65 Pediatric Spine Trauma Figure 4 Spine boards used for transportation of young children should be modified to include either an occipital recess (top figure) or a mattress pad (bottom figure) to accommodate the relatively large head. (Reproduced from Dormans JP: Evaluation of children with suspected cervical spine injury. Instr Course Lect 2002;51:403.) Figure 3 The spinolaminar (Swischuk’s) line is used to differentiate pseudosublux- ation from true injury. (Reproduced from Copley LA, Dormans JP: Cervical spine disor- ders in infants and children. J Am Acad Orthop Surg 1998;6:205.) disruption of the atlanto-occipital joint. An occipital condyle facet distance of more than 5 mm from the oc- cipital condyle to the C1 facet also represents a disrup- tion of the atlanto-occipital joint. MRI also is useful for documenting soft-tissue injury associated with atlanto- occipital dislocation. Atlanto-occipital dislocation should be stabilized surgically with a posterior occiput to C1 or C2 fusion. Because of the instability of this injury, the preoperative use of a halo or traction may be contraindicated. Fractures of the Ring of C1 Figure 5 Wackenheim clivus-canal line is drawn along the clivus into the cervical spinal canal and should pass just posterior to the tip of the odontoid. (Reproduced Fractures of the ring of C1 are uncommon injuries in with permission from Menezes AH, Ryken TC: Craniovertebral junction abnormalities, in both children and adults. The mechanism of injury is an Weinstein SL (ed): The Pediatric Spine: Principles and Practice. New York, NY, Raven, axial load to the head; the force is transmitted through 1994.) the occipital condyles to the lateral masses of C1. In adults, the ring usually breaks in two places, but in chil- through the synchondrosis of C2 distally at the base of dren the open synchondrosis of C1 allows a single frac- the odontoid and appears on radiographs as a physeal ture of the ring and a greenstick fracture through the (Salter-Harris type I) injury. The fracture usually is ap- synchondrosis. Widening of the lateral masses of more parent on plain lateral radiographs, which show the an- than 7 mm beyond the borders of the axis on an AP ra- terior displacement of the odontoid. If the fracture diograph indicates an injury to the transverse ligament. through the synchondrosis has spontaneously reduced, it In children, avulsion of the ligament from its attach- appears as a nondisplaced Salter-Harris type I fracture. ments is more likely than a true rupture of the trans- CT and MRI may be necessary to fully delineate the in- verse ligament. Nonsurgical treatment is recommended jury. Most odontoid fractures in children heal unevent- for most patients with this injury. fully and complications are rare. Closed reduction is ob- tained by extension or slight hyperextension of the Odontoid Fractures neck. At least 50% apposition should be obtained (com- Odontoid fractures are one of the most common cervi- cal spine fractures in children. Most are associated with head trauma from a motor vehicle crash or a fall from a height, although odontoid fracture can occur with trivial head trauma. In children, this fracture most often occurs American Academy of Orthopaedic Surgeons 769

Pediatric Spine Trauma Orthopaedic Knowledge Update 8 Figure 6 The Powers ratio is determined by drawing a line from the basion (B) to the (most common and benign); type II, unilateral facet sub- posterior arch of the atlas (C) and a second line from the opisthion (O) to the anterior luxation with 3 to 5 mm of anterior displacement; type arch of the atlas (A). The length of line BC is divided by the length of the line OA. A ratio III, bilateral anterior facet displacement of more than 5 of more than 1 is diagnostic of anterior atlanto-occipital translation and a ratio of less mm; type IV, posterior displacement of the atlas (Figure than 0.55 indicates posterior translation. (Reproduced with permission from Parfen- 7). Types III and IV are rare, but neurologic involve- chuck TA, Bertrand SL, Powers MJ, et al: Posterior occipitoatlantal hypermobiliy in ment may be present or instantaneous death can occur; Down syndrome: An analysis of 199 patients. J Pediatr Orthop 1994; 304.) these types must be treated with great care. plete reduction of the translation is not necessary) be- Children with acute atlantoaxial rotatory sublux- fore immobilization in a Minerva or halo cast or custom ation usually report neck pain and headaches and hold orthosis for 6 to 8 weeks. Manipulation under anesthesia the head tilted and rotated to one side, resisting any ef- or open reduction and internal fixation rarely are re- forts to move the head. If the deformity becomes fixed, quired. the pain subsides but the torticollis and decreased range of motion persist. Traumatic Ligamentous Dislocation Radiographic evaluation may be difficult because of Acute rupture of the tranverse ligament is rare, re- the position of the head. AP and open-mouth odontoid ported to occur in less than 10% of pediatric cervical views should be taken with the shoulders flat and the spine injuries; avulsion of the attachment of the trans- head in as neutral position as possible. Lateral masses verse ligament to C1 is more common. The transverse that have rotated forward appear wider and closer to ligament is the primary stabilizer of an intact odontoid the midline, whereas the opposite lateral mass appears against forward displacement. The normal distance from narrower and farther away from the midline. On the lat- the anterior cortex of the dens to the posterior cortex of eral view, the lateral facet appears anterior and usually the anterior ring of C1 is 4.5 mm in children and a dis- wedge-shaped rather than the normal oval shape. Flex- tance of more than this, measured on a lateral radio- ion and extension views can be used to exclude instabil- graph, suggests disruption of the transverse ligament. ity. CT scanning is useful to show superimposition of C1 CT is useful to show avulsion of the transverse ligament on C2 in a rotated position and to determine the degree from the ring of C1. For acute injuries, reduction in ex- and amount of malrotation. Three-dimensional CT scans tension is recommended, followed by surgical stabiliza- are helpful to identify rotatory subluxation. MRI is of tion of C1 and C2 and immobilization for 8 to 12 weeks little value unless neurologic findings are present. in a Minerva cast, halo brace, or cervical orthosis. Treatment depends on the duration of symptoms. Many patients probably never receive medical treat- ment because symptoms are mild and the subluxation reduces spontaneously over a few days. If rotatory sub- luxation has been present for a week or less, a soft col- lar, anti-inflammatory drugs, and an exercise program are sufficient. If symptoms persist after a week of this treatment, head halter traction should be initiated, ei- ther in the hospital or at home; muscle relaxants and an- algesics may be needed. If the subluxation is present for longer than a month, halo traction can be used. If reduc- tion cannot be obtained or maintained, if signs of insta- bility or neurologic deficits are present, or if the defor- mity has been present for more than 3 months, posterior arthrodesis is recommended to relieve muscle spasms associated with the malrotation and produce normal head appearance. Atlantoaxial Rotatory Subluxation Hangman’s Fracture Atlantoaxial rotatory subluxation is a common cause of Bilateral spondylolisthesis of C2, or hangman’s frac- childhood torticollis and is most often caused by trauma tures, are caused by forced hyperextension and are most or infection. The most common cause is an upper respi- frequent in children younger than the age of 2 years, ratory infection (Grisel’s syndrome), but subluxation probably because of the disproportionately large head, can occur after a retropharyngeal abscess, tonsillectomy, poor muscle control, and hypermobility present in this pharyngoplasty, or trivial trauma. Atlantoaxial rotatory age group. The possibility of child abuse must be consid- subluxation is classified into four types: type I, unilateral ered. Radiographs show a lucency anterior to the pedi- facet subluxation with an intact transverse ligament cles of the axis, usually with some forward subluxation 770 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 65 Pediatric Spine Trauma Figure 7 Fielding and Hawkins classification of atlantoaxial rotatory displacement showing four types of rotatory fixation. A, Type I, no anterior displacement and odontoid acting as the pivot. B, Type II, anterior displacement of 3 to 5 mm and one lateral articular process acting as the pivot. C, Type III, anterior displacement of more than 5 mm. D, Type IV, posterior displacement. (Reproduced with permission from Dormans JP: Evaluation of children with suspected cervical spine injury. Instr Course Lect 2002;51:403.) of C2 on C3. This injury must be differentiated from a inch-lb is generally successful. In younger children, more persistent synchondrosis of the axis. Treatment is symp- pins (up to 12) placed with lower insertional torques (2- tomatic, with immobilization in a Minerva cast, halo, or to 4-inch-lb) have been advocated (Figure 8). Standard cervical orthosis for 8 to 12 weeks. If union does not oc- pediatric halo rings fit most children, but infants and cur, posterior or anterior arthrodesis can be done to sta- toddlers usually require custom sizing. Although stan- bilize the fracture. dard pediatric halo vests are available, custom vests or body casts generally provide superior fit and immobili- Subaxial Injuries zation. Fractures and dislocations involving C3 through C7 are Spinal Cord Injury Without Radiographic rare in children and infants. Because these injuries occur Abnormality most frequently in older children and adolescents and have fracture patterns similar to those in adults, they The possibility of spinal cord injury without radio- generally can be treated as in adults. Atlantoaxial screws graphic abnormality (SCIWORA) should be considered and lateral mass plates have been used successfully for in children, particularly in patients younger than 8 years. fixation of unstable fractures of the cervical spine in SCIWORA is defined as spinal cord injury in a patient children. Image-guided techniques make accurate place- in whom there is no visible fracture on plain radio- ment of these implants easier in a child’s small verte- graphs or CT scan. MRI may be diagnostic in showing brae. spinal cord edema or hemorrhage, soft-tissue or liga- mentous injury, or apophyseal end plate or disk disrup- Pediatric Halo Use tion, but is completely normal in approximately 25% of patients. SCIWORA is the cause of paralysis in approxi- Halo vest immobilization is being used with increasing mately 20% to 30% of children with injuries of the spi- frequency in children with cervical spine injuries. It af- nal cord. Involvement of the cervical spine has been fords superior immobilization to a rigid cervical collar found to be slightly more common than other levels in and is easier to apply and more versatile than a Minerva most studies. cast. It permits access for skin and wound care while avoiding the skin problems (maceration, ulceration) typ- Potential mechanisms of SCIWORA include hyper- ically associated with both hard collars and casts. How- extension of the cervical spine, which can cause com- ever, complication rates as high as 68% have been re- pression of the spinal cord by the ligamentum flavum ported with pediatric halo use. The most common followed by flexion, which can cause longitudinal trac- problems are pin site infections; however, pin perfora- tion; transient subluxation without gross failure; or un- tion and brain abscesses have also been reported. The recognized cartilaginous end plate failure (Salter-Harris thickness of the skull in children is decreased and, in type I fracture). Ligamentous laxity, hypermobility of children younger than age 6 years, it has been suggested the spine, and immature spinal vasculature are thought that CT of the skull to measure calvarial thickness can to be contributing factors. Regardless of the specific be helpful in determining optimal sites for pin place- mechanism, injury to the spinal cord in this syndrome ment. occurs because of the variable elasticity of the elements of the immature spinal column. Experimentally, it has In children older than 6 years, the standard adult been shown that the bone, cartilage, and soft tissue in halo construct using four pins (two anterolaterally, two the spinal column can stretch about 2 inches without posterolaterally) inserted at standard torques of 6- to 8- disruption but that the spinal cord ruptures after a 0.25- American Academy of Orthopaedic Surgeons 771

Pediatric Spine Trauma Orthopaedic Knowledge Update 8 spine to prevent recurrent injury. Immobilization with a rigid cervical collar for 2 to 3 months is usually ade- quate treatment of SCIWORA. There have been no re- ports of recurrent spinal cord injury when the cervical spine has been immobilized in this manner. Surgery is occasionally necessary for unstable injury patterns. The prevalence of scoliosis following infantile paralysis is more than 90% for patients with quadriplegia and 50% for patients with paraplegia. Long-term follow-up to monitor for spinal deformity is necessary. Figure 8 Photograph of a 2-year-old patient showing a halo construct with a total of Thoracic and Lumbar Fractures 10 pins placed with lower insertional torques (2- to 4-inch-lb). Thoracic, lumbar, and sacral fractures are relatively un- inch displacement. Spinal cord injury occurs when de- common in children. Most of these injuries are caused formation of the musculoskeletal structures of the spinal by motor vehicle crashes or falls. The most common in- column exceeds the physiologic limits of the spinal cord. juries are compression fractures and flexion-distraction injuries. In infants and young children, nonaccidental Neurologic injury may be complete or incomplete. trauma (child abuse) may be a cause of significant spi- Partial spinal cord syndromes reported in SCIWORA nal trauma. Avulsion fractures of the spinous processes, include Brown-Séquard, anterior, and central cord syn- fractures of the pars or pedicles, or compression frac- dromes, as well as mixed patterns of injury. Incomplete tures of multiple vertebral bodies are the most common neurologic injuries have a good prognosis for recovery, patterns of injury that usually occur from severe shaking whereas complete injuries carry a dismal prognosis. Ap- or battering. These injuries may be associated with other proximately 50% of patients have delayed onset of neu- signs of child abuse, including fractures of the skull, ribs, rologic symptoms or late neurologic deterioration after or long bones and cutaneous lesions. Apophyseal end an initially less severe degree of injury. plate fractures or slipped apophyses are injuries that are unique to older children and teenagers whose symptoms SCIWORA may also occur in the thoracolumbar mimic disk herniation. spine in association with high-energy thoracic or ab- dominal trauma. The mechanisms of injury include vas- Compression fractures are caused by a combination cular insult to the watershed area of the spine associ- of hyperflexion and axial compression. Because the disk ated with profound/prolonged hypotension, distraction in children is stronger than cancellous bone, the verte- mechanism in the seatbelt-restrained patient, or hyper- bral body is the first structure in the spinal column to extension mechanism following a crush injury as most fail. It is common for children to sustain multiple com- often occurs when a child is rolled over by a car while in pression fractures. Compression rarely exceeds more the prone position, resulting in the spine collapsing into than 20% of the vertebral body. When loss of vertebral the chest cavity. body height exceeds 50%, the possibility of injury to the posterior column of the spine should be considered and Prognosis following SCIWORA is correlated to MRI is best evaluated with CT. Most of these fractures are findings, if any are present, and to the severity of neuro- treated nonsurgically with rest, analgesics, and bracing. logic injury. Children younger than 10 years are more Surgical stabilization may be indicated if there is poste- likely to have permanent paralysis than older children, re- rior column involvement and instability. flecting differences in the types of injuries that occur in these two age groups. SCIWORA in younger children is Flexion-distraction injuries (seat belt injuries) occur in usually the result of higher-energy trauma such as a mo- the upper lumbar spine in children wearing a lap belt. tor vehicle crash, whereas in older children the mechanism With sudden deceleration, the belt slides up on the abdo- of injury is more likely to be the result of a lower-energy men where it acts as a fulcrum. As the spine rotates event such as sports-related trauma or a fall. around this axis it fails in tension, resulting primarily in disruption of the posterior column with variable patterns Effective treatment requires careful evaluation of of extension into the middle and anterior column. Four the cervical spine to exclude osseous or cartilaginous in- patterns of injury have been described. Type A is a bony jury or mechanical instability, and stabilization of the disruption of the posterior elements extending to a vari- able degree into the middle column. Type B is an avulsion of the spinous process with facet joint disruption or frac- ture and extension into the vertebral apophysis. Type C is a disruption of the interspinous ligament with a fracture of the pars interarticularis extending into the body. Type 772 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 65 Pediatric Spine Trauma D is a posterior ligamentous disruption with laminar frac- clude two levels above and below the fracture. In chil- ture and disruption of the vertebral apophysis. Because of dren with complete neurologic deficits, longer constructs the transverse plane of orientation of this group of inju- provide better stability and may prevent subsequent ries, abnormalities may be missed by thick-section CT and paralytic spinal deformity from occurring. may not be detected even with complementary thin sec- tions, unless sagittal reconstructions are included. A lat- Annotated Bibliography eral radiograph showing widening of the interspinous space is the most helpful study in diagnosing this fracture, Specific Cervical Spine Injuries although increased distance between the spinous pro- cesses may occasionally be seen on the AP radiograph. Flynn JM, Closkey RF, Mahboubi S, Dormans JP: Role MRI may be the single best imaging modality because it of magnetic resonance imaging in the assessment of pe- can accurately identify soft-tissue and disk injury as well diatric cervical spine injuries. J Pediatr Orthop 2002;22: as having predictive value in determining spinal cord and 573-577. neural injury. In this study of 74 children, MRI confirmed the plain radi- Approximately two thirds of patients have intra- ography diagnosis in 66% and altered the diagnosis in 34%. abdominal injuries including ruptures of internal organs MRI is valuable in the evaluation of potential cervical spine and mesenteric tears, which may be life-threatening if injury, especially in obtunded children or those with equivocal not diagnosed and treated appropriately. Neurologic in- plain radiographs. jury is unusual. Lap belt injuries with mostly bony in- volvement and kyphosis less than 20° can be treated Kenter K: Worley G, Griffin T, Fitch RD: Pediatric trau- with hyperextension casting. Those with posterior liga- matic atlanto-occipital dislocation: Five cases and a re- mentous disruption and soft-tissue injury require surgi- view. J Pediatr Orthop 2001;21:585-589. cal stabilization with compression instrumentation and posterior arthrodesis. Of five children with traumatic atlanto-occipital disloca- tion, the three survivors had posterior occipitovertebral fu- Fracture of the vertebral end plate (slipped vertebral sions. The diagnosis was missed initially in three children. The apophysis) usually occurs in teenagers and is character- authors recommend detailed measurements of the initial cer- ized by traumatic disruption of the vertebral ring apo- vical spine radiographs in pediatric patients at risk for trau- physis and disk into the spinal canal. The clinical symp- matic atlanto-occipital dislocation. toms are essentially the same as a herniated disk. Patients may have muscle weakness, sensory changes, Lustrin ES, Karakas SP, Ortiz AO, et al: Pediatric cervi- absent reflexes, and root tension signs. This injury most cal spine: Normal anatomy, variants, and trauma. commonly involves the caudal end plate of L4, but may Radiographics 2003;23:539-560. occur at any level in the lumbar spine. The injuries may be purely cartilaginous with herniation of the apophysis Knowledge of the normal embryologic development and and disk or osseous with fractures of the cortical and anatomy of the cervical spine is important to avoid mistaking cancellous rim of the vertebral body. This injury usually synchondroses for fractures and to correctly interpret imaging cannot be identified on plain radiographs. CT or MRI is studies. Familiarity with mechanisms of injury and appropriate needed to make the diagnosis. Treatment is removal of imaging modalities also aids in the correct interpretation of ra- the bony and cartilaginous fragments and usually re- diographs of the pediatric cervical spine. quires more extensive exposure (bilateral laminotomies) than simple diskectomy. Thoracic and Lumbar Fractures Fracture-dislocations of the spine are unstable inju- Clark P, Letts M: Trauma to the thoracic and lumbar ries that usually occur at the thoracolumbar junction spine in the adolescent. Can J Surg 2001;44:337-345. and often are associated with neurologic deficits. They are rare injuries in children that require surgical stabili- This article describes thoracolumbar fractures in adoles- zation and fusion. Burst fractures are also rare injuries cents. The treatment of these injuries follows many of the in children that result from axial compression and typi- same principles as spinal fractures in adults. Nonsurgical treat- cally occur at the thoracolumbar junction or in the lum- ment is used more frequently because there is less spinal insta- bar spine. The need for surgical treatment is determined bility and better tolerance of bed rest and spinal immobiliza- by the stability of the fracture and the presence of neu- tion in this population. rologic deficits. Nonsurgical treatment is a viable option in neurologically intact children, although most will de- Lalonde F, Letts M, Yang JP, Thomas K: An analysis of velop a progressive angular deformity during the first burst fractures of the spine in adolescents. Am J Orthop year after the fracture. It has been shown that surgical 2001;30:115-120. stabilization prevents kyphotic deformity and decreases the length of hospitalization. Instrumentation should in- This article describes the results of treatment in 11 chil- dren (average age 14.4 years) with burst fractures of the spine; 6 children were treated with posterior spinal fusion and instru- mentation. Results showed that (1) mild progressive angular deformity developed at the site of the fracture; (2) spinal in- strumentation and fusion prevented kyphotic deformity and American Academy of Orthopaedic Surgeons 773

Pediatric Spine Trauma Orthopaedic Knowledge Update 8 decreased the length of hospitalization without contributing to tal dislocation: Underdiagnosis, recognition, treatment, further spinal cord injury; and (3) nonsurgical treatment was a and review of the literature. Pediatr Neurosurg 1994;21: viable option in neurologically intact children, but progressive 105-111. angular deformity occurred during the first year after the frac- ture. Dormans JP, Criscitiello AA, Drummond DS, Davidson RS: Complications in children managed with immobili- Reddy SP, Junewick JJ, Backstrom JW: Distribution of zation in a halo vest. J Bone Joint Surg Am 1995;77: spinal fractures in children: does age, mechanism of in- 1370-1373. jury, or gender play a significant role? Pediatr Radiol 2003;33:776-781. Finch GD, Barnes MJ: Major cervical spine injuries in children and adolescents. J Pediatr Orthop 1998;18:811- Of the 2,614 pediatric patients referred to a trauma center 814. over a 5-year period, 84 sustained vertebral fracture and 50 had neurologic injury without radiographic abnormality. A to- Glass RB, Sivit CJ, Sturm PF, Bulas DI, Eichelberger tal of 164 fractures were identified. The thoracic region (T2- MR: Lumbar spine injury in a pediatric population: Dif- T10) was most commonly injured, accounting for 47 fractures ficulties with computed tomographic diagnosis. (28.7%), followed by the lumbar region (L2-L5) with 38 frac- J Trauma 1994;37:815-819. tures (23.2%), the midcervical region with 31 fractures (18.9%), the thoracolumbar junction with 24 fractures Harris JH, Carson GC, Wagner LK: Radiologic diagno- (14.6%), the cervicothoracic junction with 13 fractures (7.9%), sis of traumatic occipitovertebral dissociation: 1. Normal and the cervicocranium with 11 fractures (6.7%). There was no occipitovertebral relationships on lateral radiographs of relationship to gender or mechanism of injury. supine subjects. AJR Am J Roentgenol 1994;162:881-886. Sledge JB, Allred D, Hyman J: Use of magnetic reso- Herzenberg JE, Hensinger RN, Dedrick DK, Phillips nance imaging in evaluating injuries to the pediatric WA: Emergency transport and positioning of young thoracolumbar spine. J Pediatr Orthop 2001;21:288-293. children who have an injury of the cervical spine. J Bone Joint Surg Am 1989;71:15-22. This study is a retrospective review of 19 children with thoracolumbar fractures associated with neurologic deficits Judd DB, Liem LK, Petermann G: Pediatric atlas frac- from three level 1 trauma centers. The authors conclude that ture: a case of fracture through a synchondrosis and re- MRI is the imaging modality of choice for these fractures be- view of the literature. Neurosurgery 2000;46:991-994. cause it can accurately classify injury to bones and ligaments and because the cord patterns as determined by MRI have Mubarak SJ, Camp JF, Vueltich W, et al: Halo applica- predictive value of neurologic status. tion in the infant. J Pediatr Orthop 1989;9:612-614. Classic Bibliography Odent T, Langlais J, Glorion C, et al: Fractures of the odontoid process: a report of 15 cases in children Akbarnia BA: Pediatric spine fractures. Orthop Clin younger than 6 years. J Pediatr Orthop 1999;19:51-54. North Am 1999;30:521-536. Pouliquen JC, Kassis B, Glorion C, Langlais J: Vertebral Banerian KG, Wang AM, Samberg LC, Kerr HH, Weso- growth after thoracic or lumbar fracture of the spine in lowski DP: Association of vertebral end plate fracture children. J Pediatr Orthop 1997;17:115-120. with pediatric lumbar intervertebral disk herniation: Value of CT and MR imaging. Radiology 1990;177:763- Subach BR, McLaughlin MR, Albright AL, Pollack IF: 765. Current management of pediatric atlantoaxial rotatory subluxation. Spine 1998;23:2174-2179. Donahue DJ, Muhlbauer MS, Kaufman RA, Warner WC, Sandford RA: Childhood survival of atlantooccipi- 774 American Academy of Orthopaedic Surgeons