Orthopaedic Knowledge Home Study by R. Alexander

Genetic Diseases and Skeletal Dysplasias Orthopaedic Knowledge Update 8 Annotated Bibliography children with congenital pseudarthrosis of the tibia: The effect of treatment. J Pediatr Orthop 1998;18:381-386. General Reference The authors of this study report that patients with healed Flynn M, Pauli R: Double heterozygosity in bone congenital pseudarthrosis of the tibia demonstrated muscle growth disorders: Four new observations and review. weakness and inefficient gait compared with patients who Am J Med Genet 2003;121A:193-208. were treated by amputation. This article reviews the complex progeny with double het- Parisini P, Di Silvestri M, Greggi T, Paderni S, Cervellati erozygosity and reports that matings between individuals with S, Savini R: Surgical correction of dystrophic spinal short stature are common. curves in neurofibromatosis: A review of 56 patients. Spine 1999;24:2247-2253. Unger S: A genetic approach to the diagnosis of skeletal dysplasia. Clin Orthop 2002;401:32-38. In this study of patients with neurofibromatosis who un- derwent surgical correction of dystrophic spinal curves, the au- The author recommends that molecular investigation of a thors report that the failure incidence of posterior instrumen- skeletal dysplasia should be undertaken only after a limited tation and fusion alone was 53% of patients, and for combined differential diagnosis is established. anterior fusion and posterior fusion it was 23%. Trisomy 21 (Down Syndrome) Hereditary Multiple Exostosis Doyle JS, Lauerman WC, Wood KB, Krause DR: Com- Duncan G, McCormick C, Tufaro F: The link between plications and long-term outcomes of upper cervical heparan sulfate and hereditary bone disease: Finding a spine arthrodesis in patients with Down syndrome. function for the EXT family of putative tumor suppres- Spine 1996;21:1223-1231. sor proteins. J Clin Invest 2001;108:511-516. In this outcome study of patients with Down syndrome The authors of this article review the biology of EXT pro- who underwent upper cervical spine arthrodesis, 11 of 15 pa- teins in vivo and explore the possible roles of these proteins in tients (73%) had 23 major complications, including nonunion, normal bone development and the formation of exostoses. loss of reduction, neurologic deterioration, late subaxial insta- bility, infection, and wound dehiscence. Winell J, Burke SW: Sports participation of children Koziel L, Kunath M, Kelly OG, Vortkamp A: Ext1- with Down syndrome. Orthop Clin North Am 2003;34: dependent heparan sulfate regulates the range of Ihh 439-443. signaling during endochonral ossification. Dev Cell 2004; 6:801-813. The authors report that patients with Down syndrome can actively participate in athletic activities if their orthopaedic Exostosin 1 is necessary for the synthesis of heparan sul- problems are appropriately managed. fate chains of proteoglycans. These regulate the signaling of several growth factors. The authors also found that the loss of Turner’s Syndrome tout velu in Drosophila inhibits Hedgehog movement. Batch J: Turner syndrome in childhood and adolescence. Skeletal Dysplasias Best Pract Res Clin Endocrinol Metab 2002;16:465-482. Aldegheri R, Dall’Oca C: Limb lengthening in short The authors provide a review of the clinical features of pa- statured patients. J Pediatr Orthop B 2001;10:238-247. tients with Turner’s syndrome and discuss management issues. In this article, the authors provide a good review of limb Ogata T: SHOX haploinsufficency and its modifying fac- lengthening for stature. tors. J Pediatr Endocrinol Metab 2002;15:1289-1294. Cooper S, Flaitz C, Johnston D, Lee B, Hecht J: A natu- This article describes the clinical findings and pathophysi- ral history of cleidocranial dysplasia. Am J Med Genet ology of SHOX mutations in patients with Turner’s syndrome. 2001;104:1-6. Neurofibromatosis This is a review of orthopaedic and other abnormalities observed in patients with cleidocranial dysplasia. The authors Durrani AA, Crawford AH, Choudry SN, Saifuddin A, also provide management recommendations. Morley TR: Modulation of spinal deformities in patients with neurofibromatosis type I. Spine 2000;25:69-75. Dalvie S, Skinner J, Vellodi A, Noorden M: Mobile tho- racolumbar gibbus in Morquio Type A: The cause of In this review of 91 patients with neurofibromatosis and paraparesis and its management. J Pediatr Orthop B spinal deformity, the authors report that nondystrophic curves 2001;10:328-330. may modulate into dystrophic curves, particularly before age 7 years. In this article, the authors report that supine spine MRI may underestimate spinal stenosis and cord compression be- Karol LA, Haideri NF, Halliday SE, Smitherman TB, cause of mobility of the thoracolumbar kyphosis in patients Johnston CE II: Gait analysis and muscle strength in with Morquio syndrome. 674 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 56 Genetic Diseases and Skeletal Dysplasias Gomez P, Garcia O, Ginebreda M, Gairi T, Vilarrubius The authors of this article report that scoliosis is common G: Lumbar canal stenosis in achondroplasia: Prevention among patients with diastrophic dysplasia; types include early and correction of lumbosacral lordosis. An Esp Pediatr progressive in 10% of patients, idiopathic-like in 50%, and 2001;54:126-131. mild nonprogressive in 40%. The authors of this article report that femoral lengthening Stanley G, McLoughlin S, Beals RK: Observations on improves lumbar hyperlordosis and reduces the symptoms of the cause of bowlegs in achondroplasia. J Pediatr lumbar spinal stenosis. Orthop 2002;22:112-116. Helenius I, Remes V, Tallroth K, Peltonen J, Possa M, The authors of this study report that tibia vara increased Paavilainen T: Total hip arthroplasty in diastrophic dys- during growth in patients with achondroplasia and that plasia. J Bone Joint Surg Am 2003;85-A:441-447. younger children with this disorder tended to have proximal tibial varus and older children tended to have distal tibial The authors of this article report that the rate of implant varus. Increased fibular length was thought to play a role. survival is good and that Harris hip scores increased signifi- cantly in patients with diastrophic dysplasia who underwent Classic Bibliography total hip arthroplasty. Kitoh H, Kitakoji T, Kurita K, Katoh M, Takamine Y: Bailey JA II: Orthopaedic aspects of achondroplasia. Deformities of the elbow in achondroplasia. J Bone J Bone Joint Surg Am 1970;52:1285-1301. Joint Surg Br 2002;84:680-683. Bethem D, Winter RB, Lutter I, et al: Spinal disorders of The authors of this article report that posterior bowing of dwarfism: Review of the literature and report of eighty the distal humerus (primarily) and posterior dislocation of the cases. J Bone Joint Surg Am 1981;63:1412-1425. radial head result in loss of elbow extension. Fairbank T: Dysplasia epiphysealis multiplex. Br J Surg Morgan K, Rehman M, Schwartz R: Morquio’s syn- 1947;34:325. drome and its anaesthetic considerations. Paediatr Anaesth 2002;12:641-644. Hastbacka J, Superti-furga A, Wilcox WR, Rimoin DL, Cohn DH, Lander ES: Sulfate transport in chondrodys- The authors of this article provide a review of anesthetic plasia. Ann N Y Acad Sci 1996;785:131-136. care for children with Morquio syndrome. Kopits SE: Orthopaedic complications of dwarfism. Clin Munns C, Glass I, LaBrom R, et al: Histopathological Orthop 1976;114:153-179. analysis of Leri-Weill dyschondrosteosis: Disordered growth plate. Hand Surg 2001;6:13-23. Mackenzie WG, Bassett GS, Mandell GA, Scott CI Jr: Avascular necrosis of the hip in multiple epiphyseal dys- The authors of this article report that the zone of dyschon- plasia. J Pediatr Orthop 1989;9:666-671. drosteosis is characterized by marked disruption of the normal physeal arrangement. Peltonen JL, Hoikka V, Poussa M, Paavilainen T, Kaitila I: Cementless hip arthroplasty in diastrophic dysplasia. Remes V, Marttinen E, Poussa M, Helenius I, Peltonen J Arthroplasty 1992;7(suppl):369-376. J: Cervical spine in patients with diastrophic dysplasia: Radiographic findings in 122 patients. Pediatr Radiol Poussa M, Merikano J, Ryoppy S, Marttinen E, Kaitila I: 2002;32:621-628. The spine in diastrophic dysplasia. Spine 1991;16:881- 887. The authors of this article report that the most common alignment of the cervical spine in adulthood is cervical lordo- Remes V, Marttinen E, Poussa M, et al: Cervical kypho- sis and that degenerative changes are common. As the preva- sis in diastrophic dysplasia. Spine 1999;24:1990-1995. lence of spina bifida occulta is high, the authors recommend that care be taken during the surgical approach for patients Ribbing S: Studien uber Hereditaire multiple Epiphy- with diastrophic dysplasia. senstorungen. Acta Radiol 1937;1(suppl):34. Remes V, Poussa M, Peltonen J: Scoliosis in patients Ryoeppy S, Poussa M, Merikanto J, Marttinen E, Kaitila with diastrophic dysplasia: A new classification. Spine I: Foot deformities in diastrophic dysplasia: An analysis 2001;26:1689-1697. of 102 patients. J Bone Joint Surg Br 1992;74:441-444. American Academy of Orthopaedic Surgeons 675



Chapter 57 Neuromuscular Disorders in Children John F. Sarwark, MD Arash Aminian, MD David E. Westberry, MD Jon R. Davids, MD Lori A. Karol, MD Myelomeningocele often correlates with the last intact laminar arch (Table 1). Ambulation is generally predicted by age 2 years. A Myelomeningocele (spina bifida, myelodysplasia) is the child with myelomeningocele who is not a community most common major birth defect, with an incidence in ambulator by the age of 6 years is not likely to reach the United States ranging from 0.6 per 1,000 to 0.9 per this goal. 1,000 births. This neural tube defect results from embry- ologic failure of closure of neural crests during the neu- Serial, well-documented orthopaedic and neurologic rulation phase of the spine in the third to fourth week examinations are key components in detecting and after fertilization. The failure results in a cerebrospinal avoiding progressive deterioration caused by neurologic fluid-filled swelling of dura and arachnoid with spinal loss. Major areas of concern include loss of motor func- nerve roots contained in the sac. In 85% to 95% of pa- tion and rapid progression of scoliosis. Common causes tients, the disorder is caused by dietary deficiency of of increasing spasticity and loss of function include hy- folate. Daily supplementation of 0.4 mg (400 µg) of folic drocephalus, shunt malfunction, tethered cord, syringo- acid before conception and during the pregnancy re- myelia, and posterior fossa compression from Arnold- duces the risk of neural tube defects significantly. Chiari malformation. Prenatal diagnosis via enzyme elevation of maternal Hip Deformities serum α-fetal protein has an accuracy rate of 60% to 95% for screening neural tube defects. An improved ul- Hip flexion contracture in children with myelomeningo- trasonographic technique for prenatal diagnosis also has cele is caused by muscle imbalance (weak extensors/ allowed informed prenatal assessment for possible elec- strong flexors), spasticity as seen in tethered cord pa- tive termination. Cesarean section is the preferred tients, or habitual sitting posture. During the first method of delivery when the diagnosis is known be- 2 years of life, hip flexion contracture decreases except cause it avoids trauma to the large myelomeningocele in high thoracic-level patients. Surgery is usually not in- and its neural elements. Fetal sac closure surgery has dicated in patients younger than 2 years of age. In pa- been postulated to improve neurologic outcome. In one tients with high thoracic lesions, flexion contracture of study of 59 patients, intrauterine myelomeningocele re- 30° to 40° may be tolerated. Greater than 30° to 40° of pair reduced the incidence of hindbrain herniation (4% contracture will result in impairment of standing ability, versus 50%) and the incidence of shunt-dependent hy- short stride length, and increased lumbar lordosis. In pa- drocephalus (58% versus 92%). Functional level was tients with low lumbar motor deficit, hip flexion con- unchanged. Currently, multicenter prospective studies to tracture of more than 20° causes decreased walking abil- assess risk and benefits of intrauterine myelomeningo- ity as a result of anterior pelvic tilt, decreased velocity, cele repair continue. and increased demand of the upper extremities. Latex allergy, sensitivity, or anaphylaxis affects 20% Treatment of hip subluxation in patients with my- to 70% of patients with myelomeningocele. The etiology elomeningocele depends on their functional level and is proposed as a result of multiple exposures to latex. the physical demand on the hip. Gait symmetry often Therefore, routine precautions, including latex-free envi- corresponds more to the absence of hip contractures ronments, should be taken to limit latex exposure. and less to the presence of hip dislocation. Therefore, hip reduction is unnecessary in the low-demand hip. Orthopaedic Considerations Management of most hips focuses on contracture re- lease and/or realignment osteotomies to prevent bracing The goal of orthopaedic treatment is to maximize func- difficulties and spinal deformities except where signifi- tion; ambulation is one main goal. Ambulation ability is cant asymmetry is present. In children with community related to the level of the last intact motor root, which American Academy of Orthopaedic Surgeons 677

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 Table 1 | Motor Level and Functional Status: Myelomeningocele Group Lesion Level Muscle Involvement Function Ambulation 1 Thoracic/high lumbar No quadriceps function Sitter Some degree until age 13 years with Possible household ambulator with HKAFO, RGO RGO 95% to 99% wheelchair dependent as adults 2 Low lumbar Quadriceps and medial Household/community ambulator Require AFO and crutches, 79% community hamstring function, no with KAFO or AFO ambulators as adults, wheelchair for long gluteus medius, maximus distances; significant difference between L3 and L4 level, medial hamstring needed for community ambulation 3 Sacral Quadriceps and gluteus Community ambulator with AFO, 94% retain walking ability as adults medius function UCBL, or none High sacral No gastrosoleus strength Community ambulator with AFO, Walk without support but require AFO, have UCBL, or none gluteus lurch and excessive pelvic obliquity and rotation during gait Low sacral Good gastrocnemius-soleus Walk without AFO, gait close to normal strength, normal gluteus medius, maximus RGO = reciprocating gait orthosis; UCBL = University of California/Berkley Lab (orthosis); KAFO = knee-ankle-foot orthosis; AFO = ankle-foot orthosis; HKAFO = hip-knee-ankle-foot orthosis ambulation skills, the instability is addressed aggres- present at birth and may lead to a significant in-toeing sively with a goal of achieving concentric reduction and gait. In patients age 5 years or younger, treatment is ob- acetabular coverage for the high functioning child. servation; orthotic devices may be used. If the condition persists in a child older than 5 years of age, an external Knee Contractures and Torsional Deformities supramalleolar tibial/fibular derotation osteotomy is indi- cated. Knee flexion contractures and extension contractures are the most common knee deformity in children. Stud- Foot Deformities ies have shown that increased knee flexion during gait has a high energy cost. Correction of knee flexion con- The goal of treatment is to achieve a supple, braceable, tracture of 20° or more is indicated. In some patients, and plantigrade foot. Approximately 30% of children hamstring lengthening is insufficient and a posterior with myelomeningocele have a rigid clubfoot at birth. capsulotomy of the knee may be required. Supracondy- Initial treatment includes serial casting, but correction is lar extension osteotomy of the distal femur is recom- rarely achieved by nonsurgical treatment. Comprehen- mended in older ambulatory children with fixed flexion sive posteromedial lateral release is indicated at or be- deformity of 20° or more after failed radical knee flexor fore walking age. release. Acquired equinus deformity occurs more frequently Knee extension contractures are much less common in children with high lumbar and thoracic-level lesions. than flexion contractures. Treatment with serial casting Prevention is attempted by bracing and physical ther- to achieve 90° of flexion is successful in most patients. If apy. Heel cord resection is indicated to achieve a planti- nonsurgical treatment fails, V-Y lengthening of the grade and braceable foot. In patients with mild deformi- quadriceps is favored. ties who are high functioning, Achilles tendon resection can be performed. With severe deformity, a radical pos- Moderate and severe torsional deformities impede terior release including capsulotomy is required. walking and place abnormal stress on the knee. A study of 25 patients with lumbosacral myelomeningocele Coronal plane malalignments include valgus defor- showed that increased external tibial torsion increased mity of the ankle or the hindfoot and are commonly clinical valgus knee stress. A thigh-foot angle greater seen in patients with L4-5 level deformity; this condition than 20° significantly increased this stress and supramal- can lead to difficulty with brace fitting and pressure leolar tibial/fibular osteotomy is indicated. sores over the medial malleolus. Radiographs help de- termine the location of the deformity. Ankles in mild Internal tibial torsion is not an acquired deformity in valgus are treated with percutaneous screw hemi- a child younger than 5 years of age with spina bifida. It is 678 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children epiphysiodesis. In severe deformities and in older chil- rate of pseudarthrosis. Surgical complications include dren, supramalleolar closing wedge osteotomy is indi- wound infection (6% to 15%), fixation failure (15%), cated. For hindfoot valgus, a medial sliding osteotomy of and pseudarthrosis (7% to 28%). Patients have an im- the calcaneus with displacement of 50% of the width of proved sitting balance after surgery, but ambulation may the fragment is recommended. be more difficult. Scoliosis Cerebral Palsy Scoliosis is related to the degree of motor paralysis. Par- Epidemiology alytic spinal deformities are expected in 5% of patients with sacral level function, 25% at L5, 60% at L4, 70% at The cerebral palsies (CPs) are the most common causes L3, 80% at L2, and more than 90% at L1 and higher. of physical disability in children. They can be defined as Congenital lumbar kyphosis is a severe spinal deformity a heterogeneous group of upper motor neuron impair- occurring in 10% to 15% of patients. This deformity ment syndromes caused by chronic brain abnormalities. does not respond to bracing. Indications are variable Causes are multifactorial and include antenatal and among surgeons. Lumbar kyphosis may have deleterious postnatal insults to the developing brain. The incidence effects on pulmonary function (because of abdominal ranges from 1 to 3 per 1,000 live births. The rate of CP compression and thoracic hypokyphosis) and sitting bal- in children weighing less than 1,500 g at birth is 70 times ance, and can progress to skin ulcerations because of the higher compared with those weighing 2,500 g or more. prominent gibbus. Newer approaches to surgical man- The incidence and prevalence of CP has remained con- agement, including vertebral subtraction or decancella- stant over the past 40 years. Improved obstetrical care tion procedures with instrumentation in young patients, has resulted in fewer neonatal insults, but improved and kyphectomy in the older patient with instrumenta- neonatal care has resulted in the decreased mortality of tion, are complex and carry significant risks for morbid- more preterm infants. Although the cerebral lesion is ity and mortality. nonprogressive, musculoskeletal deformities and impair- ment can be progressive in the growing child. Physical examination of patients with spinal defor- mity includes assessment of pelvic obliquity, joint con- Major types of CP are described as spastic, dystonic, tractures, and leg length inequality as potential revers- ataxic, and hypotonic. The spastic variety is the most ible causes of spinal deformity. Clinical findings of common, with mixed varieties now being increasingly tethered cord syndrome must be considered in the as- diagnosed. The clinical spectrum of CP ranges from very sessment. Treatment with an orthotic device is advised minor impairment as seen in a patient with mild hemi- for moderate scoliotic curves. Studies have shown the plegia with minimal gait deviations to significant cogni- greatest curve progression before the age of 15 years, tive deficits and motor functional limitations as seen in and average curve progression of 5° per year for curves children with severe total body involvement. Patients greater than 40°. Intraspinal pathology such as tethering with severe CP often have comorbidities such as sei- of the spinal cord and syringomyelia contribute to curve zures, recurrent pneumonias, and difficulty eating, often progression. Although most curves progress, bracing has requiring feeding tubes. a beneficial temporary effect of delaying definitive spi- nal fusion until adult sitting height is achieved and also Care of a child with CP involves a multidisciplinary ap- supports the trunk in a functional position for those pa- proach with emphasis on early intervention therapies, tients with imbalance and hypotonia. Patients who use tone management, use of orthotic devices, and musculo- spinal orthotic devices may find independent gait re- skeletal surgery. Input from orthopaedists, physical and duced because of increased energy expenditure and bal- occupational therapists, neurologists, neurosurgeons, pedi- ance disturbances. In wheelchair-dependent patients, in- atricians, and orthotists are required to maximize the func- creasing spinal deformity may compromise sitting tion and activities of daily living of a child with CP. Treat- balance and lead to pressure sores. Prevention of sitting ment is focused during the early years of growth on tone imbalance is correlated with prevention of an unbal- management, prevention of contractures, aids for walking, anced spine to curvature of less than 40° and pelvic and multilevel bony and soft-tissue surgery to improve obliquity to less than 25°. gait. Indications for spinal fusion and instrumentation in Literature on the treatment of adult CP patients is scoliosis are progression of curve greater than 50°, poor limited. A recent survey showed that many adults with sitting balance, and pulmonary compromise not con- CP continue to have spasticity and pain-related issues, trolled by bracing. In a study of 29 patients with severe which contribute to the deteriorating ability to ambu- thoracolumbar and lumbar scoliosis, combined anterior late. Independent walking and other forms of supported and posterior instrumentation gave the best correction ambulation are often lost upon reaching adulthood. of the deformity and pelvic obliquity, and reduced the Care of adult CP patients is limited by lack of adult health and rehabilitation services. American Academy of Orthopaedic Surgeons 679

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 Outcomes Assessment threatening, occur in approximately 20% of patients and are primarily related to breakage of the catheter, cathe- With the recent focus on evidence-based medicine and ter dislodgment, infection, and skin breakdown at the the development of best practice guidelines, greater at- insertion site. Development of scoliosis in patients with tention has been focused on the assessment of outcomes baclofen pumps remains an important concern. Most in multiple domains (technical, functional, patient and pumps are implanted in patients with severe spasticity family satisfaction, and cost). Recent studies of CP pa- that interferes with function and positioning. A long- tients have had variable success using measurement in- term review of this device showed benefits in terms of struments such as the Child Health Questionnaire and decreased pain and spasm relief, better sleep, indepen- Pediatric Outcomes Data Collection Instrument and in dence, and improved ease of care. attempting to assess outcomes of treatment. A single study found considerable variability in the reliability Physical Therapy and validity of these different instruments for patients with CP. Physical therapy is the mainstay of nonsurgical treat- ment in children with motor dysfunction. Critical peri- Bone Mineral Density ods for intensive therapy include the early ambulatory years and the immediate postsurgical rehabilitation Multiple factors may adversely affect bone mineral den- phase. Debate continues regarding the method, indica- sity in children with CP. Impaired weight bearing and tions, and value of therapies offered to patients. Cur- short-term immobilization after orthopaedic surgery rently, precise objective and collaborative goal setting contribute to low bone mineral density. Poor nutrition, has been emphasized. However, a recent randomized low calcium intake, and anticonvulsants play a negative controlled study failed to show any long-term benefit in role as well. A recent controlled clinical trial showed intensive, goal-directed therapies versus the traditional that pamidronate is a safe and effective agent to in- forms of therapy. crease bone mineral density in children with CP. Recent emphasis has been placed on the weakness Treatment Modalities seen in spastic muscles. A retrospective analysis failed to show a true relationship between the degree of spastic- Botulinum Toxin ity and strength of the muscle. There was a trend toward Botulinum toxin A is a protein polypeptide chain that increased spasticity and less strength in distal muscle irreversibly binds to the cholinergic terminals at the groups compared with proximal muscle groups. neuromuscular junction and effectively inhibits release of acetylcholine from the synaptic vesicles. The toxin Orthotic Devices can be injected locally into spastic muscles, causing a rapid onset of weakness that may last for 3 to 6 months. Ankle-foot orthoses (AFOs) are commonly prescribed The most common locations benefiting from botulinum to improve gait and stability, prevent deformity, and to toxin A injection are spastic ankle plantar flexors, poste- protect surgically-treated limbs. In patients with spastic rior tibialis, hamstrings, hip adductors, and wrist flexors. diplegia, solid AFOs have been shown to improve ankle The benefits of repeated injections are still unclear. kinetics, whereas floor reaction AFOs are effective in Risks of repeat injections include lessening of the posi- correcting crouch type gait secondary to ankle plantar tive effect of the toxin as well as possible antibody for- weakness. AFOs may be used initially to prevent equi- mation. A 2000 study of repeat botulinum A toxin injec- nus contractures, and are often used to prevent recur- tions into calf muscles of patients with spastic equinus rence of deformity after botulinum toxin injection and showed similar effects after the first and second injec- casting during treatment of dynamic or mild myostatic tions, with a decrease in the duration of response after deformities of the ankle plantar flexors. The AFOs must the third and fourth injections. The long-term benefits of extend to just below the knee and have a rigid ankle, botulinum toxin have yet to be determined. leaf spring, or hinged design to prevent equinus defor- mity. Supramalleolar designs are ineffective at prevent- Baclofen ing equinus. Prevention of equinus has been shown to Baclofen is a γ-aminobutyric acid agonist that acts pe- improve walking speed and stride length for most chil- ripherally and centrally at the spinal cord level to im- dren. The efficacy of AFOs to help in overcoming func- pede the release of excitatory neurotransmitters that tional limitations and preventing contractures is yet to cause spasticity. Large doses of oral baclofen are re- be established. quired to detect changes in spasticity, often with the un- wanted side effect of sedation. Intrathecal baclofen al- Alternative Therapies lows for larger doses to reach the target tissues in the spinal cord. A synchronized implantable infusion pump Electrical Stimulation is now available. Complications, which may be life Threshold electrical stimulation is based on low- intensity, long-duration electrical transcutaneous stimu- 680 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children lation of select muscle groups. It is theorized that elec- Gait Analysis trical stimulation promotes local blood flow, increasing the size of atrophic muscles and perhaps their function. Gait analysis continues to evolve as a diagnostic and re- Early studies show improved motor performance and search tool. Using computers, cameras, reflective mark- lower incidence of falls after 3 months of treatment. ers, in-floor force plates, dynamic electromyography, and However, two recent randomized trials failed to show pedobarographs, movement in multiple planes can be any benefit in motor or ambulatory function in children captured and analyzed. Preoperative assessment of am- with CP. bulatory patients provides information across multiple joints and lends direction to appropriate procedures Hyperbaric Oxygen Therapy such as muscle tendon lengthening and rotational os- Evidence for the effectiveness of hyperbaric oxygen teotomies. therapy treatment in children with CP is largely anec- dotal. Known risks include oxygen toxicity (tremors or A recent longitudinal study using gait analysis evalu- seizures), barotrauma (tympanic membrane rupture), ated the natural progression of gait in children with CP. myopia, and pneumothorax. A randomized multicenter Gait function was shown to deteriorate over a 4-year trial showed that hyperbaric oxygen therapy had no span with respect to temporal/stride measures, passive greater effect on patients compared with breathing range of motion, and kinematic parameters. This deteri- slightly pressurized air. oration was not seen in a similar cohort who had under- gone orthopaedic intervention. Horseback Riding The postulated effects of hippotherapy involve the The application of quantitative gait analysis in clini- movement of the horse’s hind legs and pelvis to produce cal decision making is in evolution. Current controver- a three-dimensional input to the patient. Ambulatory sies are focused on the reliability and variability of data pelvic motion is therefore mimicked while riding horse- collection and interpretation between centers. Techno- back. Potential benefits include improvement in overall logic advances in motion analysis and greater experi- gross motor function, walking, running, and jumping. Us- ence with the clinical applications of the data will in- ing the Gross Motor Function Measure, a single study of crease the use of gait analysis. children with CP showed minimal improvement after 18 weeks of hippotherapy. Management of Specific Musculoskeletal Neurosurgery Complications Selective dorsal rhizotomy (SDR) selectively sections Spine dorsal rootlets from L1 to S2. Heightened responses to Spinal deformity is more commonly seen in severely af- afferent impulses from muscle spindles are interrupted fected CP patients with quadriplegia. The typical long with an end result of decreased spasticity. Concerns re- C-shaped thoracolumbar curve is resistant to bracing main regarding the effects of SDR on muscle strength. and often progresses relentlessly. The spinal deformity Original indications for SDR were limited to ambula- leads to difficulty with seating systems and unequal bal- tory patients with diplegia. Short-term results have ance secondary to pelvic obliquity. Associated comor- shown reduced spasticity and improved function when bidities are commonly present and the decision to pur- SDR is followed by intensive physical therapy. There is sue surgical correction must be done cautiously. Often, a lack of consensus in the literature regarding patient these patients have significant comorbidities such as sei- indications, surgical techniques, surgical approach, and zure disorder, poor nutritional status, and respiratory determination of which rootlets to section. Complica- compromise. Aggressive preoperative and postoperative tions, although rare, include bowel or bladder inconti- care is required. Current techniques use segmental fixa- nence, dysesthesia, dural leaks, and risk of musculoskel- tion with Galveston fixation to the pelvis. Severe curves etal deformities including hip subluxation and may require an additional anterior procedure to achieve spondylolysis, spondylolisthesis, and scoliosis. A meta- adequate correction. A recent review of skeletally im- analysis of three randomized clinical trials showed func- mature patients (with open triradiate cartilage) with tional improvement and reduced spasticity in carefully neuromuscular scoliosis following posterior spinal fu- selected CP patients after SDR and physical therapy sion to the pelvis revealed minimal evidence of subse- when compared with physical therapy alone. Other quent progression of the deformity caused by anterior studies have shown the need for additional orthopaedic overgrowth, also known as the crankshaft phenomenon. procedures in a significant percentage of patients who have undergone SDR. Hip Hip subluxation secondary to spastic hip adductors and flexors may become evident in children between the ages of 2 to 4 years and is typically seen in children with severe spasticity. AP radiographs of the pelvis should be obtained at regular intervals to monitor for subluxation. American Academy of Orthopaedic Surgeons 681

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 Typical findings include acetabular dysplasia (usually su- formed more commonly. Nonselective Achilles tendon perior or posterosuperior), increased femoral antever- lengthening is reserved for more severe myostatic defor- sion, and increased femoral neck-shaft angle. Soft-tissue mities. There is greater risk of overlengthening with release of the adductors shows a failure rate of 40%. Achilles tendon lengthening, which can result in disrup- Osteotomies of the proximal femur (varus-producing) in tion of the ankle plantar flexion-knee extension couple, addition to acetabular osteotomies improve the cover- leading to a crouch gait pattern. age and stability of the developing hip and are typically done after age 4 years. Combined procedures may carry Foot an increased risk of proximal femoral osteonecrosis. Planovalgus and hallux valgus deformities are common in patients with CP. In nonambulatory patients, a shoe- Untreated hip dislocation in the older child or young able plantigrade foot is the goal of treatment. In ambu- adult remains a difficult diagnostic and therapeutic chal- latory patients, treatment is directed toward correction lenge. Recent studies show that not all dislocated hips of skeletal lever arm deficiency to maximize ankle plan- are painful and not all painful hips are dislocated. De- tar flexion function and to facilitate bracing. Surgical termining the degree of pain from a dislocated hip re- treatment involves posterior calf muscle lengthening mains difficult. Long-term benefits of salvage operations and skeletal realignment by calcaneal lengthening such as proximal femoral resection or hemiarthroplasty and/or subtalar arthrodesis. Hallux valgus deformities are yet to be determined. For patients with unilateral often require metatarsophalangeal fusion in patients hip dislocation and the absence of spinal deformity, hip with CP to prevent recurrence. fusion may be an alternative procedure, with a recent review showing diminished pain and postural improve- Equinovarus foot deformity is seen in the setting of ment following hip fusion in a series of older patients a spastic posterior tibialis tendon. For flexible deformi- with CP. ties, surgical considerations include posterior calf lengthening, intramuscular or Z-lengthening of the pos- Knee terior tibial tendon, or split posterior or anterior tibial Spastic hamstring muscles increase knee flexion during tendon transfers. A recent long-term follow-up survey the stance phase of gait. Untreated knee flexion con- showed a failure rate in 75% of patients with low-level tractures and worsening crouch gait can lead to in- ambulatory diplegia and quadriplegia undergoing these creased loads across the patellofemoral joint, resulting procedures before age 8 years. in pain and late arthritis. Decreased dynamic range and poor transition from stance to swing secondary to rectus Transverse Plane femoris spasticity are commonly seen. Treatment con- In some ambulatory patients with CP, increased femoral sists of medial hamstring lengthening with concomitant anteversion fails to resolve with growth, resulting in le- posterior transfer of the rectus tendon. Knee flexion ver deficiency at the level of the hip. Assessing the de- contractures following hamstring lengthening can be ad- gree of pathologic femoral anteversion requires some dressed using serial stretch casting during the postoper- combination of clinical examination, two-dimensional ative period. Lateral hamstring release is reserved for CT, and gait analysis. Compensatory actions during the the older patient with resistant knee flexion contrac- gait cycle include internal rotation of the hip and exter- tures or for patients with previous medial hamstring re- nal rotation of the pelvis to restore the lever arm. Cor- lease. Risks of lateral hamstring lengthening include ex- rection of these deviations can be achieved following cessive weakness leading to knee hyperextension during correction of the increased anteversion by derotational the stance phase. Extension osteotomy can be per- osteotomy of the femur. This procedure can be per- formed at the level of the distal femur for resistant con- formed proximally by an intertrochanteric or subtro- tractures. chanteric osteotomy, or distally above the metaphyseal flare. A prospective study comparing both methods Ankle showed excellent clinical results with either technique. If Equinus is the most common deformity in CP and this condition is not corrected by the teenage years, pa- causes adverse effects during standing and gait. For chil- tients may develop compensatory increased external tib- dren younger than 3 years of age, developmental ther- ial torsion. In such cases, the transverse plane malalign- apy and orthotic devices are used. From ages 3 to 6 ment may need to be corrected at both the femoral and years, a combination treatment with serial casting, botu- tibial levels. Tibial rotation osteotomy is best performed linum toxin, and orthotic devices is recommended. De- at the supramalleolar level to minimize the risk of com- finitive muscle-tendon surgery is preferably delayed un- partment syndrome and neurologic injury. Simultaneous til at least age 6 years for persistent equinus deformity procedures will necessitate an aggressive postoperative to minimize risk of recurrence. Surgical options vary de- physical therapy regimen to enable the patient to return pending on the degree of deformity and contracture. Se- to their preoperative functional level. lective gastrocnemius-soleus complex recession is per- 682 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children Figure 1 Patient with Duchenne muscu- lar dystrophy show the Gowers’ maneuver. A, The prone position. B, The bear posi- tion. C, Moving the hands up the thighs to help upright the trunk and augment knee extension. D, The upright position. (Repro- duced from Sussman M: Duchenne mus- cular dystrophy. J Am Acad Orthop Surg 2002;10:138-151.) Muscular Dystrophy Duchenne muscular dystrophy should be suspected in boys whose laboratory values show extremely high lev- The mutation that causes Duchenne muscular dystrophy els of serum creatine phosphokinase (measuring 10 to is a point deletion of a segment of the dystrophin gene, 200 times normal), which leaks across the defective cell located at Xp21 on the X chromosome. This produces a membrane into the serum. The diagnosis is definitively frame shift resulting in all messenger RNA distal to the made by absent dystrophin staining of muscle biopsy deletion coding for a nonsense protein. Thus, formation specimens in patients who do not have discoverable mu- of the dystrophin protein is absent. Dystrophin is critical tations. to the stability of the cell membrane. Becker muscular dystrophy resembles Duchenne muscular dystrophy in Because of the relatively common presentation of that it is also inherited in an X-linked recessive manner. the clumsy child, diagnosis of Duchenne muscular dys- A less significant mutation in the dystrophin gene does trophy is often missed for up to 2 years following pre- not result in a frame shift, and therefore allows produc- sentation. Early diagnosis is extremely important to tion of smaller amounts of an inferior dystrophin. The families because of the possibility of genetic counseling onset of weakness in patients with Becker muscular dys- for future offspring. Clinical features seen in young boys trophy is delayed usually until the second decade, and with Duchenne muscular dystrophy are a waddling gait, life expectancy is longer. This difference in the mutation toe walking, falling, and difficulty climbing stairs. Walk- results in a significant difference in disease severity such ing is usually delayed until age 18 to 24 months. Unlike that the amount and quality of dystrophin produces a in patients with spinal muscular atrophy, deep tendon spectrum of disease. reflexes are present. Gowers’ sign is positive, as the child uses the hands to “walk up” the legs when rising Duchenne muscular dystrophy can be diagnosed us- from the floor because of proximal muscle weakness ing DNA analysis in at least two thirds of patients. American Academy of Orthopaedic Surgeons 683

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 Figure 2 Physical findings in pa- lis tendon transfer to prolong ambulation would choose tients with Duchenne muscular dys- to have the surgery again. Willingness to use knee- trophy. A 5-year-old boy with Duch- ankle-foot orthoses and compliance with postoperative enne muscular dystrophy and marked physical therapy must be evaluated preoperatively. Iso- pseudohypertrophy of the calves. (Re- lated foot surgery consisting of posterior tibialis tendon produced from Sussman M: Duch- transfer (combined with Achilles tendon lengthening enne muscular dystrophy. J Am Acad and toe flexor tenotomy) corrected equinovarus, al- Orthop Surg 2002;10:138-151.) lowed patients to continue to wear shoes, and had high patient and family satisfaction. (Figure 1). Documentation of the Gowers’ sign should be mandatory in all boys evaluated for weakness or gait Scoliosis is a major problem in the nonambulatory disturbances. Calf pseudohypertrophy develops as mus- patient with Duchenne muscular dystrophy. Shortly af- cle is replaced by fibroadipose tissue (Figure 2). Gait is ter transitioning to wheelchair use, up to 95% of pa- wide-based, and lumbar lordosis is increased. tients develop scoliosis, which is progressive in almost all patients. Bracing is contraindicated because it does Research is underway in gene therapy using ade- not prevent progression, and may delay surgery until a novirus vectors in animal models to import the normal time when the pulmonary status of the child precludes dystrophin gene. The production of an immune response safe surgery. Forced vital capacity has been found to de- to introduction of the gene and reaction to the viral vec- crease 4% yearly, and an additional 4% for each 10° of tors are complications of this therapy. Stem cell and myo- thoracic deformity. Treatment is early posterior spinal blast transplant are also under investigation. fusion, recommended after a curve reaches 20° to 30° of magnitude in boys without significant cardiomyopathy, Corticosteroids have been shown to acutely improve and whose preoperative pulmonary function tests reveal muscular strength, and to slow progressive weakening in forced vital capacity of at least 35% of normal levels. intermediate follow-up. Ambulation may be prolonged Most authors recommend fusion with segmental instru- and the deterioration of pulmonary function slowed mentation from the upper thoracic spine to the sacrum with corticosteroid therapy. The preferred steroid and or pelvis, although there are reports of maintenance of mode of administration is debated. Although positive correction following fusion to L5 in patients with mini- effects on skeletal muscle have been shown, side effects mal (< 10°) preoperative pelvic obliquity, especially with such as obesity and osteopenia are of concern. the use of pedicle screw fixation distally. Outcomes studies suggest improved quality of life in boys who Advances in pulmonary care have resulted in longer have undergone spinal fusion compared with their peers life spans. A recent study revealed that patients who use who have not had surgery. nighttime ventilation have up to 50% survival at age 25 years. Fractures are more prevalent in patients with Du- chenne muscular dystrophy, occurring in up to 21% of Orthopaedic Manifestations affected boys. Frequent falls, combined with osteopenia, lead to the increased frequency. Loss of mobility occurs Hip abductor and hamstring releases, Achilles tendon in up to 20% of ambulatory boys with Duchenne mus- lengthening or release with posterior tibialis tenotomy cular dystrophy as a result of fractures. or transfer may prolong ambulation in those patients whose ability to walk is deteriorating. Timing of the sur- Spinal Muscular Atrophy gery is very important because those children who have already become nonambulatory will not regain the abil- Spinal muscular atrophy represents a group of diseases ity to walk after surgery. In a recent study, 42% of boys characterized by progressive symmetric muscular weak- who underwent multilevel releases with posterior tibia- ness caused by the loss of anterior horn cells. Spinal muscular atrophy is inherited as an autosomal recessive trait. A mutation in the survival motor neuron gene on chromosome 5q can be detected in 94% of patients. The survival motor neuron gene is critical to RNA metabo- lism and is a mediator of apoptosis (programmed cell death). Spinal muscular atrophy can be diagnosed using DNA analysis or by muscle biopsy. Muscle enzyme lev- els are usually normal. Prenatal diagnosis is possible. Subtypes of spinal muscular atrophy are distin- guished by the age of onset and clinical severity. Type I, known as Werdnig-Hoffmann or acute infantile spinal muscular atrophy, is a lethal condition presenting in pa- 684 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children tients 6 months of age or younger. The babies exhibit lit- 1,500 abnormal guanine-adenosine-adenosine repeats. tle or no movement of their extremities, with character- The number of added repeats may correlate with the se- istic tongue fasciculations and absent deep tendon verity of disease or age of onset. Frataxin is a mitochon- reflexes. Most die of respiratory infections before the drial protein, involved in iron metabolism and oxidative age of 2 years. Longer survival is possible with trache- stress. Knowledge of the role of frataxin has led to the ostomy or noninvasive ventilation. Orthopaedic treat- initiation of treatment with antioxidants such as Coen- ment is limited to splinting of fractures that may occur zyme Q, which has been shown in preliminary studies to at birth. decrease the rate of cardiac deterioration but not the ataxia. Patients with type II or chronic infantile spinal mus- cular atrophy, present between 6 and 12 months of age. Orthopaedic Manifestations These babies have muscle weakness that is more ad- vanced in the legs than in the arms. They achieve head Patients with Friedreich’s ataxia often present for the control, and most can sit, but they cannot walk. Survival evaluation of frequently falling and have cavus or into adulthood is common. cavovarus feet. Surgery to prolong ambulation is per- formed in selected patients when the position of the Type III spinal muscular atrophy is known as foot exacerbates the instability during gait. Scoliosis oc- Kugelberg-Welander syndrome and has an age of onset curs in more than 80% of patients. Curve types vary be- between 2 and 15 years, when proximal muscle weak- tween idiopathic-looking curves to long, sweeping tho- ness becomes noticeable. Patients ambulate as children, racolumbar curves. Increased thoracic kyphosis is but become wheelchair users in adulthood. common. Progression is linked to early age at diagnosis and to curve magnitude. Bracing is ineffective at pre- Orthopaedic Manifestations venting progression, and may interfere with mobility. Curves that stabilize at less than 40° at skeletal maturity Currently there is no effective medical treatment for rarely progress. Surgery is indicated for curves of 60° or spinal muscular atrophy. Orthopaedic treatment is greater. Posterior spinal fusion from the upper thoracic needed for scoliosis, which is widespread in patients to the lower lumbar spine is effective. with type II and III. Soft orthotic devices can delay but not prevent surgery in children younger than 10 years of Charcot-Marie-Tooth Disease age. Posterior spinal fusion is recommended for most progressive curves, with fusion to the pelvis in nonam- Charcot-Marie-Tooth disease is a clinically and geneti- bulatory patients. cally heterogeneous group of hereditary motor senso- rineuropathies. Traditionally, Charcot-Marie-Tooth dis- Hip dislocation and subluxation occur in 62% of ease has been divided into demyelinating forms that hips in patients with type II spinal muscular atrophy, slow nerve conduction velocity (Charcot-Marie-Tooth and less frequently in type III patients. Although open types 1, 3, and 4), and axonal forms that decrease the reduction of the hip can be performed, even with con- compound muscle action potential (Charcot-Marie- comitant pelvic osteotomy, redislocation frequently oc- Tooth type 2). Overlap between these two forms exists. curs because of the inherent muscle weakness. Long- To date, 10 genes causing various forms of Charcot- term studies show that nearly all hip dislocations in Marie-Tooth disease have been identified. These genes patients with spinal muscular atrophy remain painless; are expressed either by Schwann cells and/or accompa- surgery should be avoided in nonambulatory patients. nying neurons. The most common mutation involves overexpression of the peripheral myelin protein 22 gene Friedreich’s Ataxia on chromosome 17, producing autosomal dominant Charcot-Marie-Tooth disease type 1A. Other genes Friedreich’s ataxia is characterized by involvement of commonly disturbed include the myelin protein zero the cerebellum and the spinal cord pathways. Clinically, gene, and connexin 32, which is present in the x-linked patients present with the classic triad of ataxia, loss of Charcot-Marie-Tooth disease. deep tendon reflexes, and an extensor Babinski re- sponse. Associated medical conditions include hyper- In most patients the disease manifests during the trophic cardiomyopathy, and in some patients, diabetes second decade of life. Cavovarus foot deformity is fre- mellitus. The average age of onset is 12 years, and death quently the presenting symptom. Physical examination occurs on average 25 years after diagnosis because of is notable for lower limb areflexia, calf atrophy, an in- cardiac deterioration. creased longitudinal arch, and clawing of the toes. Friedreich’s ataxia is inherited in an autosomal re- Orthopaedic Manifestations cessive fashion. The disease is caused by the presence of an expanded guanine-adenosine-adenosine trinucleotide The first line of treatment of mild cavus and cavovarus repeat in both copies of the frataxin gene on chromo- is the use of orthotic devices. AFOs can improve gait in some 9. The normal number of repeats is less than 33, whereas patients with Friedreich’s ataxia have 66 to American Academy of Orthopaedic Surgeons 685

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 patients with flexible deformities. Patients with Charcot- repair of 13 patients showed one third were spared the need Marie-Tooth disease frequently have significant foot for a shunt at 1 year of age, but improvement in neurologic drop during swing phase, and this is improved by use of function was unclear. AFOs. Nolden MT, Sarwark JF, Vora A, Grayhack JJ: A Surgical treatment of the cavovarus foot deformity is kyphectomy technique with reduced perioperative mor- based on the flexibility of the deformity. In patients with bidity for myelomeningocele kyphosis. Spine 2002;27: mild flexible hindfoot varus, plantar fascia release and 1807-1813. first metatarsal dorsal closing wedge osteotomy, with or without transfer of the peroneus longus to peroneus Evaluation of 11 patients with myelomeningocele and brevis, can improve the deformity. The posterior tibialis lumbar kyphosis showed subtraction vertebrectomy with pos- tendon can be transferred to the dorsum of the midfoot terior instrumentation to be a safe and efficacious technique to improve swing phase foot drop. When the hindfoot is for correction and stabilization of myelomeningocele kyphosis rigid, calcaneal osteotomy is necessary. After correction in young patients. of the hindfoot deformity is achieved, metatarsal osteot- omies to align the forefoot may be performed. Alterna- Scoliosis tively, midfoot dorsal closing wedge osteotomy improves cavovarus by correcting midfoot and forefoot equinus. Berven S, Bradford DS: Neuromuscular scoliosis: In severe cases, triple arthrodesis is necessary to obtain Causes of deformity and principles for evaluation and and maintain correction. Clawing of the toes may be im- management. Semin Neurol 2002;22:167-178. proved with transfer of the toe extensors to the metatar- sal necks. Although initial results following cavovarus In a review of the literature, outcomes in patients with surgery are usually satisfactory, progression of the neu- neuromuscular deformity who were treated with a combined rologic disease often leads to recurrence of deformity. anterior and posterior fusion showed improvement of the ma- jor curve of up to 60%, more effective correction of pelvic Hip dysplasia is also associated with Charcot-Marie- obliquity, and a decreased pseudarthrosis rate. Tooth disease. Ambulatory patients may report symp- toms during adolescence. Symptomatic acetabular dys- Trivedi J, Thomson JD, Slakey JB, Banta JV, Jones PW: plasia can be treated by pelvic osteotomies. Patients Clinical and radiographic predictors of scoliosis in my- with hereditary motor sensorineuropathies are more elomeningocele. J Bone Joint Surg Am 2002;84-A:1389- prone to sciatic nerve palsy after pelvic surgery. 1394. Scoliosis occurs more frequently in patients with In a retrospective review of patients with myelomeningo- Charcot-Marie-Tooth disease. Left thoracic and ky- cele over a 5-year period with an average follow-up of 9.4 photic curves distinguish the radiographic appearance of years, curves of less than 20° often resolved. Clinical motor many of these curves from idiopathic scoliosis. Although level, ambulatory status, and last intact laminar arch were pre- bracing rarely is effective, surgical correction can be per- dictive factors for development of scoliosis. formed without an increase in complications. Cerebral Palsy Annotated Bibliography Anderson C, Mattsson E: Adults with cerebral palsy: A Myelomeningocele survey describing problems, needs, and resources, with special emphasis on locomotion. Dev Med Child Neurol Gabrieli AP, Vankoski S, Dias L, et al: Gait analysis in 2001;43:76-82. low lumbar myelomeningocele patients with unilateral hip dislocation or subluxation. J Pediatr Orthop 2003;23: This article presents a report of a survey of adult CP pa- 330-334. tients discussing natural history and progression. Of those polled, 77% had difficulty with spasticity, 18% had full disabil- Gait symmetry using motion analysis of 20 patients with ity pension, 35% reported decreased walking ability, and 18% low lumbar myelomeningocele with unilateral hip dislocation had pain every day. or subluxation and no scoliosis corresponded to the absence of hip contractures and had no relation to the presence of hip Bell KJ, Ounpuu S, DeLuca PA, Romness MJ: Natural dislocation. The authors concluded that reduction of the hip is progression of gait in children with cerebral palsy. unnecessary. J Pediatr Orthop 2002;22:677-682. Farmer DL, von Koch CS, Peacock WJ, et al: In utero re- Using clinical measures and gait analysis, gait function in pair of myelomeningocele: Experimental pathophysiol- patients with CP decreased longitudinally compared with the ogy, initial clinical experience, and outcomes. Arch Surg group who had orthopaedic intervention. 2003;138:872-878. Bower E, Michell D, Burnett M, Campbell M, McLellan Fetoscopic repair of neural tube defects before 22 weeks’ D: Randomized control trial of physiotherapy in 56 chil- gestation is physiologically and technically feasible. Surgical dren with cerebral palsy followed for 18 months. Dev Med Child Neurol 2001;43:4-15. 686 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children Patients in aim and goal directed therapy showed no ad- No relationship between strength and spasticity in patients vantage in acquisition of gross motor function or performance with CP was identified. compared with patients undergoing more traditional forms of therapy. Saraph V, Zwick EB, Zwick G, Steinwender C, Stein- wender G, Linhart W: Multilevel surgery in spastic di- Flynn JM, Miller F: Management of hip disorders in pa- plegia: Evaluation by physical examination and gait tients with cerebral palsy. J Am Acad Orthop Surg 2002; analysis in 25 children. J Pediatr Orthop 2002;22:150- 10:198-209. 157. This review article discusses surgical options for hip disor- Clinical, kinematic, and kinetic improvements are shown ders in CP. Childhood and adult hip pathology with treatment following multilevel bony and soft-tissue procedures in ambu- options are discussed. latory CP patients. Graham K, Selber P: Musculoskeletal aspects of cere- Smucker JD, Miller F: Crankshaft effect after posterior bral palsy. J Bone Joint Surg Br 2003;85:157-166. spinal fusion and unit rod instrumentation in children with cerebral palsy. J Pediatr Orthop 2001;21:108-112. A comprehensive review of the role of the orthopaedic surgeon in the management of CP is detailed. The etiology, In skeletally immature children with cerebral palsy, poste- natural history, pathophysiology, and surgical strategies are rior spinal fusion alone with unit rod instrumentation was suc- discussed. cessful in maintaining correction of neuromuscular scoliosis. Crankshaft deformity was not identified in this series of 50 pa- Henderson RC, Lark RK, Kecskemethy HH, Miller F, tients treated with isolated posterior procedures. Harcke HT, Bachrach SJ: Bisphosphonates to treat os- teopenia in children with quadriplegic cerebral palsy: A Sterba J, Rogers B, France A, Vokes D: Horseback randomized, placebo-controlled clinical trial. J Pediatr riding in children with cerebral palsy: Effect on gross 2002;141:644-651. motor function. Dev Med Child Neurol 2002;44:301-308. This small clinical trial demonstrated increased bone min- A small clinical trial evaluated the effect of recreational eral density following administration of bisphosphonates in horseback riding therapy on Gross Motor Function Measure nonambulatory children with CP. scores. An increase of 7.6% in these scores was seen after 18 weeks of horseback riding therapy and returned to control McLaughlin J, Bjornson K, Temkin N, et al: Selective levels 6 weeks following therapy. A minimal increase in walk- dorsal rhizotomy: Meta-analysis of three randomized ing, running, and jumping ability was seen after horseback controlled trials. Dev Med Child Neurol 2002;44:17-25. riding therapy. A consistent reduction in spasticity in seen following selec- Vitale MG, Levy DE, Moskowitz AJ, et al: Capturing tive dorsal rhizotomy (SDR). With respect to functional out- quality of life in pediatric orthopaedics: Two recent come, the difference between SDR alone and SDR with phys- measures compared. J Pediatr Orthop 2001;21:629-635. ical therapy was minimal. Cross-sectional application of Child Health Questionnaire Pirpiris M, Trivett A, Baker J, Rodda G, Nattrass R, Gra- and Pediatric Outcomes Data Collection Instrument among ham H: Femoral derotation osteotomy in spastic diple- varying diagnoses. The instruments were able to distinguish gia. J Bone Joint Surg Br 2003;85:265-272. physical from psychosocial health problems. Proximal and distal femoral derotation osteotomy was Muscular Dystrophy found to be equally effective for correction of increased femo- ral anteversion and intoeing gait. Distal osteotomy may pro- Bentley G, Haddad F, Bull TM, et al: Treatment of scoli- vide faster rehabilitation and a decrease in surgical complica- osis in muscular dystrophy using modified Luque and tions. Harrington-Luque instrumentation. J Bone Joint Surg Br 2001;83:22-28. Rosenbaum PL, Walter SD, Hanna SE, et al: Prognosis for gross motor function in cerebral palsy: Creation of Sixty-four patients with Duchenne muscular dystrophy motor development curves. JAMA 2002;288:1357-1363. and 33 patients with spinal muscular atrophy had posterior spinal fusion with sublaminar wiring. Fusion to the pelvis is Evidence-based prognostication concerning gross motor recommended. progress in children with CP is discussed. Patterns of gross motor development are illustrated relating to the severity of Chan KG, Galasko CS, Delaney C: Hip subluxation and motor impairment. dislocation in Duchenne muscular dystrophy. J Pediatr Orthop B 2001;10:219-225. Ross S, Engsberg J: Relation between spasticity and strength in individuals with spastic diplegic cerebral Nineteen of 54 boys had subluxated or dislocated hips, palsy. Dev Med Child Neurol 2002;44:148-157. usually related to pelvic tilt. American Academy of Orthopaedic Surgeons 687

Neuromuscular Disorders in Children Orthopaedic Knowledge Update 8 Connolly AM, Schierbecker J, Renna R, et al: High dose Freidreich’s Ataxia weekly oral prednisone improves strength in boys with Duchenne muscular dystrophy. Neuromuscul Disord Lynch DR, Farmer JM, Balcer LJ, et al: Friedreich atax- 2002;12:917-925. ia: Effects of genetic understanding on clinical evalua- tion and therapy. Arch Neurol 2002;59:743-747. Improvement in muscle strength was seen up to 2 years following twice weekly prednisone therapy with fewer side ef- Molecular genetic research has led to the discovery of mu- fects than daily administration. tations in the frataxin gene. The link between genotype and phenotype has been studied. Treatment is under investigation Eagle M, Baudouin SV, Chandler C, et al: Survival in based on frataxin’s role in cellular responses to oxidative Duchenne muscular dystrophy: Improvements in life ex- stress. pectancy since 1967 and the impact of home nocturnal ventilation. Neuromuscul Disord 2002;12:926-929. Charcot-Marie-Tooth Disease Using nighttime noninvasive ventilation, survival averaged Berger P, Young P, Suter U, et al: Molecular cell biology 50% at 25 years of age in boys without severe cardiomyopa- of Charcot-Marie-Tooth disease. Neurogenetics 2002;4:1- thy. 15. McDonald DG, Kinali M, Gallagher AC, et al: Fracture The specific mutations in 10 genes linked with subtypes of prevalence in Duchenne muscular dystrophy. Dev Med Charcot-Marie-Tooth disease are discussed. Child Neurol 2002;44:695-698. Sammarco GJ, Taylor R: Cavovarus foot treated with Twenty-one percent of boys with Duchenne muscular dys- combined calcaneus and metatarsal osteotomies. Foot trophy sustained fractures; 48% of the fractures occurred in Ankle Int 2001;22:19-30. ambulatory patients as a result of falls, and 20% of boys ceased walking because of the fracture. Fifteen feet affected by Charcot-Marie-Tooth disease un- derwent combined calcaneal and metatarsal osteotomies with improvements in foot scores and radiographs. Scher DM, Mubarak SJ: Surgical prevention of foot de- Classic Bibliography formity in patients with Duchenne muscular dystrophy. J Pediatr Orthop 2002;22:384-391. Beaty JH, Canale ST: Orthopaedic aspects of myelo- meningocele. J Bone Joint Surg Am 1990;72:626-630. Plantigrade shoeable feet were maintained after tibialis posterior transfer, Achilles tendon lengthening, and toe flexor Botto LD, Moore CA, Khoury MJ, Erickson JD: Medi- releases. cal progress: Neural tube defects. N Engl J Med 1999; 341:1509-1519. Sengupta DK, Mehdian SH, McConnell JR, et al: Pelvic or lumbar fixation for the surgical management of scoli- Brinker MR, Rosenfield SR, Feiwell E, Granger SP, osis in Duchenne muscular dystrophy. Spine 2002;27: Mitchell DC, Rice JC: Myelomeningocele at the sacral 2072-2079. level: Long term outcomes in adults. J Bone Joint Surg Am 1994;76:1293-1300. Increasing pelvic tilt was not seen at 3.5-year follow-up af- ter posterior spinal fusion with pedicle screw fixation to L5 for Daher YH, Lonstein JE, Winter RB, et al: Spinal defor- mild curves. mities in patients with Charcot-Marie-Tooth disease: A review of 12 patients. Clin Orthop 1986;202:219-222. Sussman M: Duchenne muscular dystrophy. J Am Acad Orthop Surg 2002;10:138-151. Damiano DL, Abel MF: Functional outcomes of strength training in spastic cerebral palsy. Arch Phys A detailed review of current treatment and research on Med Rehabil 1998;79:119-125. Duchenne muscular dystrophy is presented. Delp SL, Zajac FE: Force and moment generating ca- Spinal Muscular Atrophy pacity of the lower extremity muscles before and after tendon lengthening. Clin Orthop 1992;284:247-259. Bach JR, Baird JS, Plosky D, et al: Spinal muscular atro- phy type 1: Management and outcomes. Pediatr DeLuca PA, Davis RB, Ounpuu S, Rose S, Sirkin R: Al- Pulmonol 2002;34:16-22. terations in surgical decision making in patients with ce- rebral palsy based on three-dimensional gait analysis. Although tracheostomy prolonged survival in patients J Pediatr Orthop 1997;17:608-614. with type 1 spinal muscular atrophy, noninvasive ventilation preserved speech. Drennan JC: Current concepts in myelomeningocele. Instr Course Lect 1999;48:543-550. Sporer SM, Smith BG: Hip dislocation in patients with spinal muscular atrophy. J Pediatr Orthop 2003;23:10-14. Thirty-nine of 41 patients with spinal muscular atrophy and hip dislocations were pain free at 18-year follow-up. 688 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 57 Neuromuscular Disorders in Children Galasko CS, Delaney C, Morris P: Spinal stabilization in Part I. The effect of rectus femoris transfer location on Duchenne muscular dystrophy. J Bone Joint Surg Br knee motion. J Pediatr Orthop 1993;13:325-330. 1992;74:210-214. Ounpuu S, Muik E, Davis RB III, Gage JR, Deluca PL: Greene WB: Treatment of hip and knee problems in Rectus femoris surgery in children with cerebral palsy. myelomeningocele. Instr Course Lect 1999;48:563-574. Part II: A comparison between the effect of transfer and release of the distal rectus femoris on knee motion. Hensinger RN, MacEwen GD: Spinal deformity associ- J Pediatr Orthop 1993;13:331-335. ated with heritable neurological conditions: Spinal mus- cular atrophy, Friedreich’s ataxia, familial dysautono- Perry J: Determinants of muscle function in the spastic mia, and Charcot-Marie-Tooth disease. J Bone Joint lower extremity. Clin Orthop 1993;288:10-26. Surg Am 1976;58:13-24. Read L, Galasko CS: Delay in diagnosing Duchenne Hoffman EP, Kunkel LM: Dystrophin abnormalities in muscular dystrophy in orthopaedic clinics. J Bone Joint Duchenne/Becker muscular dystrophy. Neuron 1989;2: Surg Br 1986;68:481-482. 1019-1029. Reimers J: Functional changes in the antagonists after Koman LA, Mooney JF III, Smith BP, Walker F, Leon lengthening of the agonists in cerebral palsy. Clin JM: Botulinum toxin type A neuromuscular blockade in Orthop 1990;253:30-37. the treatment of lower extremity spasticity in cerebral palsy: A randomized, doubled-blind, placebo-controlled Rose SA, Deluca PA, Davis RB III, Ounpuu S, Gage trial: BOTOX Study Group. J Pediatr Orthop 2000;20: JR: Kinematic and kinetic evaluation of the ankle after 108-115. lengthening of the gastrocnemius fascia in children with cerebral palsy. J Pediatr Orthop 1993;13:727-732. Kunkel LM: Analysis of deletions in DNA in patients with Becker and Duchenne muscular dystrophy. Nature Skaggs DL, Rethlefsen SA, Kay RM, Dennis SW, Rey- 1986;322:73-77. nolds RA, Tolo VT: Variability in gait analysis interpre- tation. J Pediatr Orthop 2000;20:759-764. Labelle H, Tohme S, Duhaime M, et al: Natural history of scoliosis in Friedreich’s ataxia. J Bone Joint Surg Am Smith AD, Koreska J, Moseley CF: Progression of scoli- 1986;68:564-572. osis in Duchenne muscular dystrophy. J Bone Joint Surg Am 1989;71:1066-1074. Lieber RL: Skeletal muscle adaptability: I. Review of basic properties. Dev Med Child Neurol 1986;28:390-396. Strauss DJ, Shavelle RM, Anderson TW: Life expect- ancy of children with cerebral palsy. Pediatr Neurol Lim R, Dias L, Vankoski S, Moore C, Marinello M, Sar- 1998;18:143-149. wark J: Valgus knee stress in lumbosacral meylomenin- gocele: A gait analysis evaluation. J Pediatr Orthop Sutherland DH, Davids JR: Common gait abnormalities 1998;18:428-433. of the knee in cerebral palsy. Clin Orthop 1993;288:139- 147. Mazar J, Menelaus MB, Dickens DR, Doig WG: Efficacy of surgical management for scoliosis in myelomeningo- Talipan N, Bruner JP, Hernandez-Schulman M, et al: Ef- cele: Correction of deformity and alteration of func- fects of intrauterine myelomeningocele repair on central tional status. J Pediatr Orthop 1986;6:568-575. nervous system structure and function. Pediatr Neurosurg 1999;31:183-188. Muller EB, Nordwall A: Brace treatment of scoliosis in children with myelomeningocele. Spine 1994;19:151-155. Mubarak SJ, Morin WD, Leach J: Spinal fusion in Duch- Walker JL, Nelson KR, Heavilon JA, et al: Hip abnor- enne muscular dystrophy: Fixation and fusion to the sac- malities in children with Charcot-Marie-Tooth disease. J Pediatr Orthop 1994;14:54-59. ropelvis? J Pediatr Orthop 1993;13:752-757. Mubarak SJ, Wenger DR, Valencia F: One-stage correc- Wetmore RS, Drennan JC: Long-term results of triple tion of the spastic dislocated hip: Use of pericapsular ac- arthrodesis in Charcot-Marie-Tooth disease. J Bone etabuloplasty to improve coverage. J Bone Joint Surg Joint Surg Am 1989;71:417-422. Am 1992;74:1347-1357. Williams JJ, Graham GP, Dunne KB, Menelaus MB: Ounpuu S, Muik E, Davis RB III, Gage JR, Deluca PL: Late knee problems in myelomeningocele. J Pediatr Rectus femoris surgery in children with cerebral palsy: Orthop 1993;13:701-703. American Academy of Orthopaedic Surgeons 689



Chapter 58 Pediatric Hematology Michael T. Busch, MD Tim Schrader, MD Gary M. Lourie, MD Hemophilia possibility of an undiagnosed coagulopathy should be considered in patients with compartment syndrome af- Hemophilia is a group of genetic bleeding disorders that ter relative minor injuries and when excessive bleeding affects about 20,000 Americans. Hemophilia is inherited is encountered during or after surgery. in about two thirds of patients; the condition results from spontaneous genetic mutations in one third of pa- Although several substances in blood produce an in- tients. The most common deficiencies involve factor flammatory reaction from the synovium, iron is thought VIII (classic hemophilia or hemophilia A) and factor IX to be the primary stimulant. In response to the inflam- (Christmas disease or hemophilia B). Because the genes mation, the synovium develops villi that are highly vas- for these deficiencies are carried on the X chromosome, cular and friable (Figure 1). These villi are then prone to they are usually recessive disorders affecting males. Fe- spontaneous hemorrhage with normal activity or minor males, who are genetic carriers of the disease, can have trauma. Once inflamed, the synovium also releases mild deficiencies and may become symptomatic after chondrolytic substances and other factors that alter the trauma or surgery. von Willebrand’s disease is a defi- normal homeostasis between osteoblasts and osteo- ciency or abnormality of von Willebrand’s factor, a large clasts, resulting in chondrolysis, periarticular osteopenia, protein that is responsible for the adherence of platelets and cyst formation. to damaged endothelium and acts as a carrier protein for the factor VIII molecule. von Willebrand’s disease Hemophilic arthropathy can develop in patients as can be inherited in either an autosomal dominant or re- young as 3 years of age. Synovitis must be treated early cessive manner, and it affects almost an equal number and aggressively to prevent hemophilic arthropathy. of males and females. Other less common clotting factor This involves medical treatment, including varying deficiencies and disorders of platelets may need to be degrees of a combination of prolonged factor replace- considered when evaluating patients for spontaneous ment, physical therapy, and activity modifications. If musculoskeletal bleeding that is spontaneous or occurs these measures are not enough to control bleeding, in- after trauma or surgery. flamed synovium may become so thick and abundant that control can only be gained from a synovectomy The hallmark symptom of severe hemophilia (factor (Figure 2, A). levels ≤ 1% of normal) is spontaneous bleeding. In these patients, bleeding occurs without any recognizable Prophylaxis trauma. Recurrent hemarthrosis, or repeated bleeding into the joints, usually begins after a child starts to walk. By infusing exogenous clotting factor concentrates on a In children, the ankles and elbows are more commonly regular basis (typically two to three times per week), the affected than the knees and shoulders. Orthopaedic sur- trough concentrations can be kept above 1% (patients geons may encounter these frequently undiagnosed dis- typically bleed when levels are below 1%). Although orders in patients who experience excessive intraopera- primary prophylaxis is a good strategy to prevent joint tive, postoperative, or posttraumatic bleeding. bleeding, there are numerous issues related to cost and Preoperative screening histories should query for fre- difficulty of ongoing administration. quent gum bleeding, epistaxis, excessive bruising, and menorrhagia. A family history should also be obtained. Demand Therapy Because mild deficiencies may not result in significant symptoms, a screening history should be obtained for all The common approach is to treat hemarthroses as they patients before surgery, particularly those undergoing occur. The first dose administered after a joint bleed more demanding procedures such as spinal fusion. The should elevate the deficient clotting factor level to 80% of normal. This decays to 5% in 48 hours (the half-life for factor VIII is 12 hours), and an additional 40% dose American Academy of Orthopaedic Surgeons 691

Pediatric Hematology Orthopaedic Knowledge Update 8 Figure 1 Histologic section of the hemosiderotic synovitis that results from recurrent tissue. Although there is still some theoretic risk of sub- hemarthrosis in a patient with severe hemophilia. Note the highly vascular villi with sequent malignant transformation after radionuclide little supporting collagen, making this area highly prone to bleeding with minor trauma synovectomy, only one associated instance has been re- or even normal joint motion. ported in a child with hemophilia, and there are no re- ports of growth disturbances. is given on the second and third days after a bleed so that levels remain above 5% for 5 days. Rest, ice, com- The procedure is typically done as an outpatient pression, and elevation are instituted immediately to re- procedure in the radiology suite, and local anesthesia is duce the severity of the bleed. As swelling resolves and usually adequate. An arthrogram is always done to con- motion returns, the child gradually resumes activities. firm intra-articular placement of the needle tip and to look for venous extravasation (which usually occurs in If a joint bleeds more than three times in 6 months, joints acutely inflamed by a bleed just before the proce- it becomes prone to developing a chronic synovitis. Sec- dure and is a contraindication to proceeding). The dos- ondary prophylaxis is instituted for 3 months. If bleed- age varies depending on the joint and the size of the pa- ing stops and the synovitis resolves, the options are to tient. Steroids are simultaneously injected to reduce the continue secondary prophylaxis indefinitely or to re- inflammatory response that can accompany the treat- sume demand therapy. If the bleeding continues on pro- ment. A small-gauge needle is used to minimize leakage phylaxis or if the synovitis fails to resolve after up the needle track, and pressure is applied afterward. 3 months, the synovitis is considered recalcitrant to Follow-up liver and spleen scans are used to look for medical management and a synovectomy becomes nec- systemic leakage, but the results of these tests are rarely essary. The primary indications for synovectomy are per- positive. Patient activities are reduced for 2 weeks, and sistent synovitis or bleeding despite 3 months of prophy- physical therapy is not usually needed. Radionuclide laxis and resumption of joint bleeding within 1 year of synovectomy generally reduces the frequency of bleeds successful prophylaxis. by 50% of patients with hemophilia. Radionuclide syn- ovectomy is ideally suited for patients with hemophilia Synovectomy is therefore a means of “rescuing” the who have developed an inhibitor, which is an immuno- joint from chronic synovitis, and it is a key treatment globulin G-mediated antibody response to the clotting modality for the successful use of demand therapy. The factor. primary objective when performing a synovectomy in these joints is to remove most of the friable villous layer Arthroscopic Synovectomy of the synovium. Perioperative hemostasis is provided by factor administration, allowing the synovium to heal. Arthroscopic synovectomy offers some advantages over The resultant synovial lining is smoother and less prone radionuclide synovectomy in that the diseased synovium to repetitive injury. is physically removed and lesions of articular cartilage can be débrided simultaneously (Figure 2, B). This pro- Radionuclide Synovectomy cedure can be done on an outpatient basis using a con- tinuous infusion pump to fully correct the deficient clot- By injecting a radioactive pharmaceutical agent into an ting factor before surgery and through the fourth affected joint, the hypertrophic synovium is ablated, re- postoperative day. Infusion is then continued every storing a smoother and less friable surface. In the other day for at least 6 to 12 weeks. The most common United States, the most commonly used substance is P32 complication, loss of motion, is associated with preexist- chromic phosphate. This substance releases primarily β ing arthritis (significant lost motion already present or radiation, which only penetrates a few millimeters into radiographic changes of joint space narrowing) or early postoperative bleeding. Arthroscopic synovectomy re- quires compliance with a rigorous preoperative and postoperative regimen of factor replacement and physi- cal therapy; therefore, a committed family and experi- enced multidisciplinary team are keys to success. Joints in children as young as 3 years can be arthroscopically treated, and early intervention significantly improves outcomes. Overall, an 80% reduction in hemarthroses can be expected, and virtually all patients should experi- ence improvement. Although the direct costs of radionuclide synovec- tomy are less than those of arthroscopic synovectomy, radionuclide synovectomy carries a higher rate of repeat procedures, and arthroscopic synovectomy may be more 692 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 58 Pediatric Hematology Figure 2 A, Arthroscopic view of the anterior compartment in the elbow of an 8-year-old boy with hemophilic (hemosiderotic) synovitis. Note the vascular villi produced by this proliferative synovitis. B, Arthroscopic view of the same region of the anterior elbow compartment seen near the completion of an arthroscopic synovectomy. Note that most of the villi have been removed, but the capsule remains intact. (Reproduced with permission from Dunn AL, Busch MT, Wyly JB, Sullivan KM, Abshire TC: Arthroscopic synovectomy for hemophilic joint disease in a pediatric population. J Pediatr Orthop 2004;24:414-426.) effective, especially in more severely affected joints. Ar- Heterozygous individuals have a normal gene for he- throscopic synovectomy also avoids the long-term risks moglobin A and a gene for hemoglobin S. Carriers are of radiation exposure. Regardless of the type of syn- typically asymptomatic because hemoglobin A still ac- ovectomy, the key to success is early intervention. Most counts for about 55% to 60% of an individual’s total he- patients with severe hemophilia who are managed with moglobin. Only rarely do individuals with sickle cell on-demand therapy protocols will develop a “target trait display symptoms. Homozygous individuals with joint” by adolescence, and an early “synovectomy res- two genes for hemoglobin S, however, have no hemoglo- cue” is essential to minimize the risk of premature ar- bin A, and every organ and tissue in the body can be ad- thritis. versely affected. Sickle Cell Disease As oxygen tension decreases, the hemoglobin S mol- ecules polymerize within the red cells and lead to alter- Normal hemoglobin is composed of α and β chains. The ation in red cell shape, membrane changes, cellular de- gene for β globulin is located on chromosome 11, and a hydration, decreased deformability, and shorter life span single substitution of valine for glutamic acid at the of the red cells. Tissues with low oxygen tension and end sixth amino acid position causes an abnormally func- vessel flow are particularly vulnerable. Musculoskeletal tioning hemoglobin (the gene for hemoglobin S) to be symptoms account for 80% of all hospital admissions. produced. Heterogeneous individuals have sickle cell trait, and homozygous individuals have sickle cell dis- In infancy, individuals with sickle cell disease are ease. Other abnormalities can occur in the α and β glob- protected by fetal hemoglobin (hemoglobin F). In in- ulin chains and cause sickle cell disorders, including fants age 4 to 6 months with sickle cell disease, the sickle cell β thalassemia, sickle cell hemoglobin D, and amount of hemoglobin F begins to decrease and symp- sickle cell hemoglobin E. toms can occur. Dactylitis (hand-foot syndrome) typi- cally presents between the ages of 6 months and 4 years. Sickle cell trait is common in western Africa, where This condition is characterized by swelling and tender- it provides some protection against malaria. In the ness in the hands or feet, and occurs in about 70% of all United States, about 10% of the African-American pop- individuals with sickle cell disease. Dactylitis is thought ulation carries the hemoglobin S gene, and 1 in 600 has to represent a vaso-occlusive episode. Treatment con- sickle cell disease. Sickle cell disease primarily affects sists of analgesia, oxygen, and hydration, with symptoms blacks, but it can occur in other ethnic groups. typically lasting 3 to 7 days. Osteomyelitis must remain in the differential diagnosis, and aspiration can be used to aid in determining the proper treatment. Dactylitis is American Academy of Orthopaedic Surgeons 693

Pediatric Hematology Orthopaedic Knowledge Update 8 rare after age 6 years, when hematopoietic marrow dis- duction, which results in a severe hemolytic, microcytic, appears in the digits. Forty percent of individuals can hypochromic anemia. Bone marrow hyperplasia ensues, have recurrent dactylitis. causing bone fragility, growth retardation, and an in- creased rate of fractures. Slipped capital femoral epi- The incidence of sickle cell crises in patients with physis and early osteoarthritis occur at increased rates. sickle cell disease is around 0.8 episodes per year. Hy- Radiographic findings include widened marrow spaces, droxyurea has been shown to decrease the number of thinned cortices, severe osteopenia, and “hair-on-end” painful episodes in adults, and a multicenter trial of hy- appearance of the skull. Extramedullary hematopoiesis droxyurea in children is currently underway. in the vertebrae can cause paraparesis by compression of the spinal cord. Increased body iron loads can cause Although individuals with sickle cell disease are tissue fibrosis, resulting in cardiomyopathy, diabetes more prone to infection, the incidence of osteomyelitis mellitus, and adrenal, parathyroid, and thyroid hypo- remains quite low (< 1% per year), and bone infarcts function. Splenectomy in childhood lessens the transfu- are 50 times more common. Nonetheless, differentiating sion requirements, but it increases the already higher between osteomyelitis and bone infarcts can be difficult than normal rate of infections. Treatments of individuals because their signs and symptoms are quite similar. with thalassemia include early transfusion therapy Pain, swelling, redness, warmth, stiffness, and elevated (maintaining hemoglobin > 9 g/dL), iron chelation, bone laboratory parameters are common. Erythrocyte sedi- marrow transplantation, splenectomy, and supportive mentation rates are unreliable in patients with sickle medical management. cell disease because of the altered red cells. Blood cul- tures should be included in routine work-up, and bone Leukemia aspiration should be done in patients with suspected sickle cell disease. Several imaging modalities have been Acute leukemia is the most common malignancy in studied to help differentiate between infection and in- childhood, accounting for nearly one third of instances farct, including bone scans and MRI. Ultrasonography of cancer in children. Acute lymphocytic leukemia ac- may be less expensive and equally effective. A recent re- counts for approximately 80% of these instances. With port has identified serum procalcitonin concentration as current therapies, approximately 80% of children with a negative predictor of serious musculoskeletal infec- acute lymphocytic leukemia now survive. tion. Common pathogens include Staphylococcus au- reus, Salmonella, and Streptococcus pneumoniae. Treat- Although leukemia is primarily a disease of the bone ment consists of antibiotics, hydration, oxygenation, and marrow, any organ can be infiltrated by the malignant surgical drainage of abscesses. Reactive arthritis and cell, and this accounts for the highly variable clinical septic arthritis can also occur. presentation. The musculoskeletal system is often in- volved, including pain in the extremities, back pain, os- Bone marrow hyperplasia can cause bony changes in teomyelitis, septic arthritis, or fracture. Twenty percent patients with sickle cell disease. Osteopenia in the verte- of patients present with a primary report of limp or ex- bral bodies can lead to bulging of the intervertebral tremity pain, and up to 50% of patients have these disks, compression fractures, and progressive kyphosis. symptoms as secondary complaints at the time of initial Long bone growth can be affected, and pathologic frac- diagnosis. Although long bone pain is the most common tures can occur. Growth retardation is common in pa- symptom, the spine may be involved. This becomes an tients with sickle cell disease, with height and weight sig- important consideration in the differential diagnosis of nificantly lower than average at 2 years of age. Skeletal the child presenting with back pain. At the onset of the maturity can also be delayed. Osteonecrosis of the fem- disease, 10% of children have normal peripheral blood oral and humeral heads commonly occurs, with preva- counts, making the diagnosis even more challenging. lences of 30% and 6%, respectively. Treatment options MRI may be helpful because it is very sensitive to mar- include restricted weightbearing, core decompression, row changes caused by infiltration and secondary inf- polymethylmethacrylate injection, vascularized fibular arct. grafts, hemiresurfacing, and total joint arthroplasty. Joint arthroplasty is complicated by higher rates of infection Painful joint swelling and fever are common present- and loosening. ing symptoms of the musculoskeletal manifestations of leukemia. These symptoms may mimic sepsis or acute Thalassemia onset of a juvenile idiopathic arthritis (formerly called juvenile rheumatoid arthritis). Typically, patients with The thalassemia syndromes comprise a heterogeneous juvenile idiopathic arthritis present with morning stiff- group of hemolytic anemias that result from mutations ness and pain localized to the joints, whereas patients that affect globulin synthesis. Normal hemoglobin is with leukemia more often present with night pain and composed of α and β chains; therefore, α and β thalas- nonarticular bone pain. The radiographs of patients with semias can occur. Individuals with thalassemia major are juvenile idiopathic arthritis may show joint effusions homozygous. There is very low to no hemoglobin A pro- 694 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 58 Pediatric Hematology and mild osteopenia surrounding joints, whereas the ra- Lower extremity anomalies occur in up to 80% of diographic changes suggestive of acute leukemia include patients, and they include severe genu varum, instability, diffuse osteopenia, metaphyseal bands, periosteal new and patellar abnormalities, which has prompted some to bone formation, geographic lytic lesions, sclerosis, mixed rename this syndrome TARK, with the letter K signify- sclerosis/lysis, and permeative destruction. ing involvement of the knee. Other associated deformi- ties include hip dysplasia, pes valgus, talipes equino- Once considered rare, acute megakaryoblastic leuke- varus, synostosis in the metatarsals, and syndactyly mia now accounts for about 12% of all instances of involving the toes. acute myeloid leukemia in children. Most instances of acute megakaryoblastic leukemia are difficult to diag- Management of patients with TAR syndrome in- nose because of their complex clinical presentation and cludes hematologic support, including platelet transfu- unusual bone marrow morphologic features. In children, sions until the patient’s condition stabilizes, usually acute megakaryoblastic leukemia is often confused with around 2 years of age. Musculoskeletal management in- metastatic solid tumors or myelodysplastic syndrome. cludes radiographs for patients with occult hip dyspla- These abnormalities (bilaterally symmetric periostitis sia. Varus angulation and internal tibial rotation usually and osteolytic lesions) differ markedly from those com- recur after corrective osteotomy, which has prompted monly reported in association with pediatric acute leu- some to advocate a more conservative management ap- kemias. proach using simple adaptive devices and powered mo- bility aids. Foot and ankle reconstruction including pos- Treatment protocols for leukemia often include sig- teromedial release and/or heel cord lengthening have nificant doses of steroids because of their antilympho- been recommended. The goals of surgical treatment of cytic effects. MRI shows changes consistent with areas the upper extremity deformities are to obtain and main- of osteonecrosis in approximately 25% of children re- tain correction of the radial deviation. The primary indi- ceiving high-dose steroid regimens. Children younger cation for upper extremity surgery correction is persis- than 10 years are generally not affected. One third or tent wrist contracture and reconstruction of function- more of those affected develop symptomatic complica- limiting thumb deficiency. tions of weight-bearing joints. When these complications do occur, treatment options are limited, and end stage Annotated Bibliography joint disease can develop. Hemophilia Thrombocytopenia With Absent Radii Butler RB, McClure W, Wulff K: Practice patterns in Thrombocytopenia with absent radii (TAR) syndrome is haemophilia A therapy: A survey of treatment centres an autosomal recessive, rare disorder characterized by in the United States. Haemophilia 2003;9:549-554. congenital hypomegakaryocytic thrombocytopenia and bilateral absence of the radius, with shortening of the This study surveyed 52 hemophilia centers with a total of ulna and a normal thumb. This syndrome develops be- 4,129 patients receiving treatment. Among patients with se- tween the fourth and eighth weeks of gestation when vere hemophilia, 49% were receiving on-demand treatment, the radii develop and platelet production begins. Signifi- whereas 44% were receiving some form of prophylaxis (13% cant complications that can occur in infancy secondary primary, 20% secondary, and 11% tertiary). Primary prophy- to thrombocytopenia include intracranial hemorrhage, laxis was the most common type in children younger than anemia, and frequent occurrences of epistaxis. Charac- 5 years, who comprised 25% of this age group. In children age teristic hematologic findings include hypomegakaryo- 6 to 18 years, 58% were receiving some type of prophylactic cytic thrombocytopenia, periodic leukemoid reactions, regimen, whereas on-demand treatment was most frequent and eosinophilia. Mortality in early infancy approaches among adult patients. 40% of patients; however, if the child is able to survive the first 1 to 2 years of life, the thrombocytopenia usu- Dunn AL, Busch MT, Wyly JB, Abshire TC: Radionu- ally resolves and the musculoskeletal problems become clide synovectomy for hemophilic arthropathy: A com- the chief manifestation of TAR. prehensive review of safety and efficacy and recommen- dation for a standardized treatment protocol. Thromb The upper extremity anomalies include bilateral ab- Haemost 2002;87:383-393. sence of the radii with radial deviation at the wrist, a shortened and bowed ulna, and normal thumbs. Re- This review article compiles the published experience to cently, an anomalous muscle spanning the elbow with its date using radionuclide synovectomy for hemophilic joint dis- origin on the humeral shaft at the deltoid tubercle and ease. A suggested treatment protocol is presented. insertion into the hand and carpal bones (termed the brachiocarpalis) has been described and its excision has Dunn AL, Busch MT, Wyly JB, Sullivan KM, Abshire been recommended to negate the strong radial devia- TC: Arthroscopic synovectomy for hemophilic joint dis- tion to the hand. ease in a pediatric population. J Pediatr Orthop 2004;24: 414-426. American Academy of Orthopaedic Surgeons 695

Pediatric Hematology Orthopaedic Knowledge Update 8 This study provides data on 47 pediatric patients who un- absent radius (TAR) syndrome and discussion of its derwent arthroscopic synovectomy (40 ankles, 22 elbows, 9 clinical significance, in American Society for Surgery of knees, and 2 shoulders) for hemophilic joint disease. The me- the Hand Meeting Abstracts, Phoenix, AZ, 2002, p 13. dian patient age at time of surgery was 10.3 years, and median Available at: http://www.assh.org. Accessed October 6, follow-up was 79 months. The authors report that joints with 2004. sufficient follow-up data showed a median bleeding frequency decline of 84% (P < 0.001). The authors of this retrospective review of 16 patients with thrombocytopenia absent radius syndrome show the presence Journeycake JM, Miller KL, Anderson AM, Buchanan of an anomalous muscle spanning the elbow (termed the bra- GR, Finnegan M: Arthroscopic synovectomy in children chiocarpalis) and emphasize its contribution to the radial de- and adolescents with hemophilia. J Pediatr Hematol formity. They recommend excision in patients with progressive Oncol 2003;25:726-731. radial deviation. In this study, 28 arthroscopic synovectomies (11 knees, 12 Classic Bibliography ankles, and 5 elbows) were done on 26 joints in 20 patients with hemophilia. The authors report that the frequency of he- Arnold WD, Hilgartner MW: Hemophilic arthropathy: marthrosis diminished significantly in the first year and was Current concepts of pathogenesis and management. maintained for up to 5 years in all but three joints. J Bone Joint Surg Am 1977;59:287-305. Sickle Cell Disease Chambers JB, Forsythe DA, Bertrand SL, Iwinski HJ, Steflik DE: Retrospective review of osteoarticular infec- Scott LK, Grier LR, Arnold TC, Conrad SA: Serum pro- tions in a pediatric sickle cell age group. J Pediatr calcitonin concentration as a negative predictor of seri- Orthop 2000;20:682-685. ous bacterial infection in acute sickle cell pain crisis. Med Sci Monit 2003;9:CR426-CR431. Christensen CP, Ferguson RL: Lower extremity defor- mities associated with thrombocytopenia in absent ra- In this preliminary study of 24 patients with sickle cell dis- dius syndrome. Clin Orthop 2000;375:202-206. ease, pain crisis, and acute inflammation, procalcitonin levels were measured and levels less than 2 ng/mL were reported to Hedberg VA, Lipton JM: Thrombocytopenia with absent have a good negative predictive value of serious infection. radii: A review of 100 cases. Am J Pediatr Hematol Oncol 1988;10:51-64. Skaggs DL, Kim SK, Greene NW, Harris D, Miller JH: Differentiation between bone infarction and acute os- Heinrich SD, Gallagher D, Warrior R, Phelan K, George teomyelitis in children with sickle-cell disease with use VT, MacEwen GD: The prognostic significance of the of sequential radionuclide bone-marrow and bone scans. skeletal manifestations of acute lymphoblastic leukemia J Bone Joint Surg Am 2001;83:1810-1813. of childhood. J Pediatr Orthop 1994;14:105-111. This is a study of 70 patients with sickle cell disease and Mattano LA Jr, Sather HN, Trigg ME, Nachman JB: Os- acute bone pain. The findings suggest that serial radionuclide teonecrosis as a complication of treating acute lympho- bone marrow and bone scan scintigraphy can provide some blastic leukemia in children: A report from the Chil- differentiation between osteomyelitis and bone infarction. dren’s Cancer Group. J Clin Oncol 2000;18:3262-3272. Leukemia McLaurin TM, Bukrey CD, Lovett RJ, Mochel DM: Management of thrombocytopenia-absent radius (TAR) States LJ: Imaging of metabolic bone disease and mar- syndrome. J Pediatr Orthop 1999;19:289-296. row disorders in children. Radiol Clin North Am 2001; 39:749-772. Schoenecker PL, Cohn AK, Sedgwick WG, Manske PR, Salafsky I, Millar EA: Dysplasia of the knee associated In this study, the author reports that MRI provides de- with the syndrome of thrombocytopenia and absent ra- tailed information about bone marrow and is gaining an in- dius. J Bone Joint Surg Am 1984;66:421-427. creasingly important role in the management of disorders of bone marrow infiltration. Thrombocytopenia With Absent Radii Carter PR, Mills J, Ezaki M: (Abstract) Anatomical de- scription of an anomalous muscle in thrombocytopenia 696 American Academy of Orthopaedic Surgeons

Chapter 59 Shoulder and Humerus: Pediatrics Ann Van Heest, MD Introduction Diagnosis of Sprengel’s deformity primarily has been made based on a physical examination; physical Familiarity with the spectrum of shoulder disorders seen characteristics include a webbed neck, a palpable scap- in children is necessary for the treatment of pediatric ula into the cervical region, and a loss of range of mo- upper extremity disorders. For the child whose symp- tion. Radiographs confirm the diagnosis. Recently, pre- toms prevent normal use of the arm, a complete evalua- natal diagnosis through the use of ultrasound has been tion should include the shoulder girdle because children described. often are unable to provide details on the history of their disorder and have difficulty localizing symptoms. Recommended treatment is based on the Cavendish classification. Grade 1 deformity is very mild with level A general classification of pediatric shoulder disor- glenohumeral joints and no visible deformity when the ders is based on congenital, developmental, or acquired patient is dressed; no functional impairment is present etiology. Congenital shoulder disorders are present at and treatment is not warranted. Grade 2 deformity is birth and are the result of abnormal fetal formation and mild with level glenohumeral joints with a visible lump development. Developmental disorders are caused by in the neck when the patient is dressed. If the cosmetic growth disturbances such as growth plate dysfunction, deformity is not acceptable, surgical treatment would in- neuromuscular disorders, systemic disease, or manifesta- clude extraperiosteal resection of the scapular promi- tions of a syndromic disorder. Acquired disorders are nence including resection of the tethering omovertebral most commonly secondary to trauma, infection, or tu- bar if present. Hypertrophic scars are common; there- mor. This classification system helps provide a general fore, parents need to be aware that the bump will be re- framework for understanding pediatric shoulder disor- placed with a scar. Grade 3 deformity is moderate with ders. 2 to 5 cm of shoulder joint elevation compared with the contralateral side, and grade 4 is a severe deformity with Sprengel’s Deformity the position of the scapula near the occiput. Surgical treatment involves not only resection of the superior an- Sprengel’s deformity is the congenital failure of descent gle of the scapula and the tethering omovertebral bar if of the scapula from the embryonic level opposite the present, but also derotation of the scapula and reloca- fifth cervical vertebra to its final normal position, with tion to a more caudal position. its superior border at the seventh cervical vertebra and with its inferior angle at the level of the sixth rib. In up The age at which surgical intervention should be un- to 50% of patients, an associated omovertebral bar has dertaken has been discussed by various authors, and the been described, consisting of a fibrous, cartilaginous, or general agreement is for intervention when the child is bony connection between the superior angle of the at least 3 years of age, which is when the child is old scapula and the cervical vertebral spinous process, lam- enough to tolerate the extensive nature of the proce- ina, or transverse process. Additionally, omoclavicular dure yet young enough to maximize correction through bars have been described. Other common associated subsequent growth. With caudal repositioning of the anomalies requiring investigation including scoliosis, scapula, there is a risk of compressive injury to the bra- spina bifida, rib anomalies, Klippel-Feil syndrome, ab- chial plexus. This risk is greatest in a child older than normal musculature, foot deformities, torticollis, facial 8 years and can be lessened by concomitant clavicular asymmetry, and pulmonary and kidney disorders. The osteotomy. incidence of these disorders is nearly equal on the right and left sides; bilaterality is reported in 10% to 30% of Surgical techniques described for scapular relocation patients. The condition is slightly more common in girls. include: (1) the Woodward procedure, which relocates the scapula by detachment and caudal relocation of the midline origin of the parascapular muscle; (2) the Green American Academy of Orthopaedic Surgeons 697

Shoulder and Humerus: Pediatrics Orthopaedic Knowledge Update 8 procedure, which relocates the scapula by extraperi- Glenoid Hypoplasia osteal detachment of scapular muscles at their scapular insertion with reattachment after caudal relocation of Normal glenoid ossification occurs through consolida- the scapula using scapular traction cables; and (3) cor- tion of the secondary ossification centers of the superior rection by vertical scapular osteotomy. Concomitant glenoid, inferior glenoid, and base of the coracoid. Fail- clavicular osteotomy or morcellization is recommended ure of normal ossification of the inferior glenoid epiphy- to reduce the incidence of neurovascular injury and to sis is a rarely diagnosed entity. The patient has limited provide anterior release allowing greater correction of abduction, mild axillary webbing, and aplasia or hypo- the deformity. plasia of the glenoid. Several cases of familial involve- ment with variable penetrance have been reported. The Woodward procedure is the most common sur- Lack of ossification of the inferior glenoid appears to gical technique used for correction of a moderate or se- cause such minimal disability that this condition is often vere Sprengel’s deformity. A recent report has con- undiagnosed, and is most commonly seen as an asymp- firmed previous findings of cosmetic and functional tomatic incidental finding or as part of other congenital improvement with this procedure. The age of the patient deficiencies. and the presence of an omovertebral bone did not influ- ence the results. Associated cervical spine anomalies Birth Brachial Plexus Palsy were indicative of a negative prognosis. The most common pattern of birth brachial plexus in- Pseudarthrosis of the Clavicle jury involves C5 and C6 neurologic injury with complete or partial paralysis of the shoulder girdle muscles. Weak- Pseudarthrosis of the clavicle in children usually is ness of the deltoid, biceps, supraspinatus, and infraspina- present at birth, with parents reporting a prominent tus results in an adduction internal rotation deformity bump at the midportion of the clavicle. Physical exami- caused by the unopposed pull of the pectoralis major, nation reveals little or no pain on palpation of mobile subscapularis, teres major, and latissimus dorsi. Second- clavicle segments with a prominence in the midportion. ary skeletal changes include retroversion of the glenoid, Shoulder range of motion is normal or hypermobile. The posterior subluxation and medial flattening of the hu- prominent bump in the midclavicle often becomes more meral head, and elongation with prominence of the ac- apparent with loss of infantile adipose tissue. If the child romion. Early radiographic changes of immature ossifi- is examined at a later age, asymmetry of the shoulder cation of the epiphysis compared with the contralateral with drooping of the affected side caused by fragment side and scapular winging are shown in Figure 1. hypermobility may be present. Difficulties with shoulder function are rare, although the recent literature has re- During infancy, treatment of the shoulder dysfunc- ported the occurrence of thoracic outlet symptoms in tion associated with brachial plexus injury is aimed at adolescence. prevention of both internal rotation contracture and secondary bone deformity during the neurologic recov- Radiologic evaluation shows lack of bone continuity ery period. Brachial plexus exploration with neurolysis, in the middle third of the clavicle without evidence of nerve repair, or nerve grafting may be indicated if bi- reactive bone. The presence of minimal pain and lack of ceps function has not returned by 6 months of age. If callus formation distinguishes this condition from a shoulder muscle weakness persists with external rota- birth fracture. Pseudarthrosis of the clavicle can be dis- tion deficiency, anterior release or lengthening of the tinguished from cleidocraniodysostosis because pseud- tight anterior structures (pectoralis major, subscapularis, arthrosis is more commonly unilateral with absence of anterior capsule) is recommended, coupled with aug- cranial or pelvic involvement. Associated cervical ribs or mentation of the deficient posterior structures (latissi- elevated first ribs may be present in pseudarthrosis of mus dorsi and teres major to rotator cuff tendon trans- the clavicle. The lesion is usually on the right side; left- fer). sided occurrence is usually in association with dextro- cardia. Bilateral occurrences have been reported. Children with a history of upper trunk brachial plexus injury with incomplete return of shoulder exter- Most children with congenital pseudarthrosis of the nal rotation usually should be monitored for develop- clavicle are asymptomatic and do not require surgical ment of skeletal changes of the glenohumeral joint. Ra- intervention. Surgery to establish union is reserved for diographic evaluation for glenohumeral dysplasia has children with an unacceptable bump, pain, or shoulder been described using plain radiographs, ultrasound, dysfunction. Surgical treatment options include resec- MRI, CT (Figure 2), and arthrography. Although the tion of the fibrous pseudarthrosis and sclerotic bone method of radiographic evaluation remains controver- ends with suturing of the bone ends, with bone grafting, sial, the necessity of monitoring children for gleno- and/or internal fixation. humeral dysplasia is not disputed. The natural history of this disease has been well defined; therefore, progressive flattening of the humeral head, posterior subluxation, 698 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 59 Shoulder and Humerus: Pediatrics Figure 1 Early radiographic changes associated with glenohumeral dysplasia in a child with upper trunk birth brachial plexus injury are shown. These changes include immature ossification of the epiphysis compared with the contralateral side with scapular winging. Secondary skeletal changes include retroversion of the glenoid, posterior subluxation, medial flattening of the humeral head, and elongation with prominence of the acromion. eventual dislocation of the joint, and increased retrover- sion of the glenoid is highly probable. Surgical interven- tion should be done using tendon transfer surgery be- fore significant glenohumeral dysplasia develops. Recent studies have shown that loss of passive external rotation with the arm in adduction is an early finding on physical examination that glenohumeral dysplasia is de- veloping. If fixed skeletal deformity of the glenohumeral joint exists, a humeral osteotomy with external rotation of the distal fragment is recommended (Figure 3). Recent studies also have shown that a posterior dis- location can occur in association with birth brachial plexopathy even in infancy (younger than 1 year of age). Whether this condition represents an early mani- festation of a severe muscle imbalance or whether the condition occurred acutely at the time of birth is cur- rently unknown. A high index of suspicion for posterior dislocation is essential in the evaluation of an infant with brachial plexus injury at birth. If diagnosed, an open reduction may be necessary. Clavicle Fractures Figure 2 A CT scan more effectively evaluates glenohumeral dysplasia. Radiographic measurements should include glenoid version and the percent of humeral head cover- A recent study that prospectively screened newborn in- age. fants for clavicle fractures reported the incidence of 5 frac- American Academy of Orthopaedic Surgeons 699

Shoulder and Humerus: Pediatrics Orthopaedic Knowledge Update 8 Figure 3 Severe fixed glenohumeral dysplasia in the skeletally mature adolescent occurs with untreated residual upper trunk dysfunction. Because of the severity of the dysplasia and loss of passive joint motion, a humeral rotation osteotomy was necessary for treatment. A and B, Preoperative radiographs. C, CT scan. D, Postoperative radiograph. tures per 1,000 live births. The fractures occurred equally During the first decade of life, 88% of clavicle frac- on the right and left side and occurred equally in males tures are midshaft and 55% are nondisplaced. A recent and females. All fractures occurred during vaginal deliv- report of surgical treatment of clavicle fractures indi- eries. No clavicle fractures occurred with breech presen- cated that over a 21-year period, only 15 patients with tation. Risk factors for fracture included large birth clavicle fractures required surgical stabilization. Surgical weight, shoulder dystocia, mechanically assisted delivery, treatment was indicated primarily in the older child with and prolonged gestational age. One in 11 newborns with a displaced, unstable fracture pattern. Intramedullary a clavicle fracture had an associated brachial plexus palsy. elastic nails or plates and screws are options for internal 700 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 59 Shoulder and Humerus: Pediatrics fixation. However, surgery is very rarely needed for pe- mentation rate (that may rise above 100 mm/hr) and in- diatric clavicle fractures. creased white blood cell count also may be seen. After an isolated nondisplaced midshaft clavicle The initial radiographs are frequently normal; ultra- fracture, the risks of nonunion, malunion, or neurovas- sonography supports the diagnosis in some patients by cular complications are exceptionally rare; therefore, showing an accumulation of fluid inside the joint space. follow-up beyond the initial diagnostic visit is rarely Aspiration of synovial fluid from the affected gleno- necessary. humeral joint is necessary to evaluate the offending pathogen. In a recent review, false-negative Gram stains Proximal Humerus and Shaft Fractures occurred in approximately 90% of patients, whereas synovial fluid cultures showed the pathogen in 88% of Fractures of the proximal humerus are relatively rare patients. Blood cultures were positive in 90% of pediat- (0.5% of all childhood fractures), compared with the ric patients. The most common isolated pathogen was more common distal radius, supracondylar elbow, and Staphylococcus aureus, which accounted for 41% of in- forearm shaft fractures. Salter-Harris type I injuries are fections. Gram-negative bacilli, which accounted for most common in neonates and children younger than about 20% of infections, are more prevalent in the pedi- age 5 years; metaphyseal fractures are most common in atric population, especially in neonates. children 5 to 11 years old; and Salter-Harris type II frac- tures are most common in those older than 11 years. Pyogenic shoulder arthritis should be treated with intravenous antibiotics after synovial fluid aspiration Diagnosis of proximal humeral fractures in the new- and joint irrigation. Irrigation (using a wrist arthro- born may be difficult because these fractures must be scope) or arthrotomy may be chosen. distinguished from septic arthritis, brachial plexus inju- ries, and clavicle fractures in the infant with pseudopa- The close proximity of the proximal humeral meta- ralysis of the arm. Plain films may not be helpful in the physis to the shoulder joint capsule, as well as the perfo- diagnosis because the proximal humerus epiphysis does rating vessels from the physis to the metaphysis of the not ossifiy until after 6 months of age. MRI, ultrasound, proximal humerus, necessitate investigation to deter- or aspiration/arthrogram may be necessary. As the child mine if septic arthritis of the shoulder joint coexists with approaches skeletal maturity, pain with arm dysfunction, osteomyelitis of the proximal humerus. About half of af- a history of a fall on an outstretched hand, or a direct fected children have both conditions. Treatment of sep- blow to the shoulder region along with positive radio- tic arthritis in these children should include intravenous graphs confirm the diagnosis. antibiotics and drilling of the metaphyseal bone of the proximal humerus at the time of joint washout. The Fractures of the proximal humerus are usually presence of persistent pain, swelling, and fever in chil- treated using closed techniques. The need for a closed dren who have had an arthrotomy or arthroscopy for reduction is determined by the extent of displacement septic arthritis of the shoulder may indicate concurrent and the remodeling remaining, based on the child’s age. osteomyelitis. General guidelines include up to 70° of angulation in the child younger than 5 years old; 40° to 70° of angula- Certain systemic diseases such as sickle cell disease tion in the child 5 to 12 years old; and up to 40° of angu- tend to be more closely associated with the develop- lation in the child older than 12 years. ment of osteomyelitis. Tuberculous osteomyelitis of the proximal humerus has been described, with the diagno- When reduction cannot be achieved, or when reduc- sis confirmed by tissue biopsy and culture. The presence tion is lost as the arm is moved down to the side, percu- of Mycobacterium tuberculosis is confirmed by its taneous pinning is usually recommended. Open reduc- growth at body temperature on the agar in the tions are reserved for special circumstances such as in Löwenstein-Jensen culture medium, or can be seen his- patients with associated injuries, open injuries, concomi- tologically with caseating granulomas. The importance tant glenohumeral dislocation, or significant muscle in- of tissue diagnosis cannot be overemphasized. A high terposition. In patients with open injuries, the use of ex- degree of suspicion in patients from immigrant popula- ternal fixation has been used with good results. tions is appropriate, as osteomyelitis is more common in this patient group. Septic Arthritis and Osteomyelitis Annotated Bibliography Septic arthritis of the shoulder joint remains an uncom- mon and difficult diagnosis that requires a high index of Sprengel’s Deformity suspicion. The disease usually involves very young in- fants and has a high prevalence of associated infections. Chinn DH: Prenatal ultrasonographic diagnosis of In a recent review of the literature, elevated body tem- Sprengel’s deformity. J Ultrasound Med 2001;20:693-697. perature was present in 90% of pediatric patients with septic arthritis and was the most constant finding of the This article describes the use of ultrasound for prenatal di- physical examination. An increased erythrocyte sedi- agnosis of Sprengel’s deformity. American Academy of Orthopaedic Surgeons 701

Shoulder and Humerus: Pediatrics Orthopaedic Knowledge Update 8 Khairouni A, Bensahel H, Csukonyi Z, Desgrippes Y, Clavicle Fractures Pennecot GF: Congenital high scapula. J Pediatr Orthop B 2002;11:85-88. Calder JD, Solan M, Gidwani S, Allen S, Ricketts DM: Management of paediatric clavicle fractures: Is This recent review of the Woodward procedure confirms follow-up necessary? An audit of 346 cases. Ann R Coll the cosmetic and functional improvements achieved. Seventy- Surg Engl 2002;84:331-333. nine percent of patients had good or excellent results. This study recommends that there is no need for follow-up Pseudarthrosis of the Clavicle of children with isolated, uncomplicated midshaft clavicle frac- tures; these fracture patients can be discharged after their first Lorente Molto FJ, Bonete Lluch DJ, Garrido IM: Con- assessment in fracture clinic. genital pseudarthrosis of the clavicle: A proposal for early surgical treatment. J Pediatr Orthop 2001;21:689- Kubiak R, Slongo T: Operative treatment of clavicle 693. fractures in children: a review of 21 years. J Pediatr Or- thop 2002;22:736-739. This article presents a review of six children with congeni- tal pseudarthrosis (ages 18 months to 4 years). The patients This report on the surgical treatment of clavicle fractures were surgically treated with bone graft and internal fixation; showed that, during a 21-year period, only 15 patients with healing of the pseudarthrosis was obtained in all patients in 6 clavicle fractures required surgical stabilization. Surgery was to 8 weeks. indicated primarily in the older child with a displaced, unsta- ble fracture pattern. Intramedullary elastic nails were the pre- Glenoid Hypoplasia ferred method of internal fixation. de Bellis U, Guarino A, Castelli F: Glenoid hypoplasia: Septic Arthritis and Osteomyelitis Description of a clinical case and analysis of the litera- ture. Chir Organi Mov 2001;86:305-309. Forward DP, Hunter JB: Arthroscopic washout of the shoulder for septic arthritis in infants: A new technique. This article discusses the skeletal changes associated with J Bone Joint Surg Br 2002;84:1173-1175. glenoid hypoplasia and describes a case of unilateral glenoid hypoplasia. The use of a wrist arthroscope for arthroscopic washout of septic arthritis of the shoulder in three children younger than Birth Brachial Plexus Palsy 3 years of age is described. Full recovery was achieved with a single intervention. Hoeksma AF, Ter Steeg AM, Dijkstra P, Nelissen GHH, Beelen A, de Jong BA: Shoulder contracture and os- Monach PA, Daily JP, Rodriguez-Herrera G, Solomon seous deformity in obstetrical brachial plexus injuries. DH: Tuberculous osteomyelitis presenting as shoulder J Bone Joint Surg Am 2003;85-A:316-322. pain. J Rheumatol 2003;30:851-856. A high prevalence of glenohumeral dysplasia on plain ra- Tuberculous osteomyelitis of the proximal humerus in chil- diographs is associated with internal rotation contracture of dren is described, along with a review of the relevant litera- the shoulder following birth brachial plexus injury. A loss of ture. passive external rotation of the shoulder was highly associated with osseous deformity of the glenohumeral joint. Classic Bibliography Moukoko D, Ezaki M, Wilkes D, Carter P: Posterior Bennek J: The use of upper limb external fixation in shoulder dislocation in infants with neonatal brachial paediatric trauma. Injury 2000;31(suppl 1):21-26. plexus palsy. J Bone Joint Surg Am 2004;86A:787-793. Cavendish ME: Congenital elevation of the scapula. Of 134 patients with neonatal brachial plexus palsy, the di- J Bone Joint Surg Br 1972;54:395-408. agnosis of posterior shoulder dislocations was made in 11 pa- tients (8%). Diagnosis was made on clinical examination and Sprengel: Die angeborene Verschieburg des Schulterb- confirmed by ultrasonography at an average patient age of 6 lattes nach oben. Arch Klin Chir 1891;42:545. months (range, 3 to 10 months). Pearl ML, Edgerton BW, Kon DS, et al: Comparison of Goddard NJ, Fixsen JA: Rotation osteotomy of the hu- arthroscopic findings with magnetic resonance imaging merus for birth injuries of the brachial plexus. J Bone and arthrography in children with glenohumeral defor- Joint Surg Br 1984;66:257-259. mities secondary to brachial plexus birth palsy. J Bone Joint Surg Am 2003;85-A:890-898. Grogan DP, Love SM, Guider KJ, Ogden JA: Operative treatment of congenital pseudarthrosis of the clavicle. The natural history of brachial plexus injury leading to in- J Pediatr Orthop 1991;11:176-180. ternal rotation contracture, which subsequently leads to gleno- Hoffer M, Wickenden R, Roper B: Brachial plexus birth palsies: Results of tendon transfers to the rotator cuff. humeral dysplasia, is documented within the first 2 years of J Bone Joint Surg Am 1978;60:691-695. life. The glenohumeral dysplasia was evaluated comparatively by MRI, arthrography, and arthroscopy. 702 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 59 Shoulder and Humerus: Pediatrics Lossos IS, Yossepowitch O, Kandel L, Yardeni D, Arber Webb LX, Mooney JF: Fractures and dislocations about N: Septic arthritis of the glenohumeral joint: A report of the shoulder, in Green NE, Swiontkowski MF (eds): 11 cases and review of the literature. Medicine (Balti- Skeletal Trauma in Children, ed 2. Philadelphia, PA, WB more) 1998;77:177-187. Saunders, 1998, pp 319-341. McBride MT, Hennrikus WL, Mologne TS: Newborn Waters PM, Smith GR, Jaramillo D: Glenohumeral de- clavicle fractures. Orthopedics 1998;21:317-320. formity secondary to brachial plexus birth palsy. J Bone Joint Surg Am 1998;80:668-677. Schnall SB, King JD, Marrero G: Congenital pseudart- hrosis of the clavicle: A review of the literature and sur- Woodward JW: Congenital elevation of the scapula: gical results of six cases. J Pediatr Orthop 1988;8:316- Correction by release and transplantation of muscle ori- 321. gins. J Bone Joint Surg Am 1961;43:219-228. American Academy of Orthopaedic Surgeons 703



Chapter 60 Elbow: Pediatrics John M. Flynn, MD Roger Cornwall, MD Pediatric Elbow Fractures Type I fractures are minimally displaced, type II are dis- placed with an intact posterior cortex, and type III frac- Pediatric elbow fractures are common; however, they tures have a completely displaced distal fragment. In are challenging to evaluate and treat even for the expe- posteromedial fractures (occurring in approximately rienced orthopaedist. The elbow of a young child is 75% of patients), the radial nerve is at risk, whereas in composed predominantly of unossified cartilage. In posterolateral fractures, the brachial artery and median older children, multiple centers of ossification make nerve are at risk. About 2% of supracondylar fractures evaluation difficult. Associated neurovascular injuries are flexion injuries with disruption of the posterior peri- frequently occur and may significantly impact the ur- osteum. The flexion pattern is considered much more gency and method of treatment. In general, the pediatric difficult to treat with standard closed pinning tech- elbow has a relatively limited remodeling capacity. The niques. A recent study of 29 flexion-type supracondylar elbow physes grow more slowly than those in the proxi- humerus fractures reported 86% good or excellent re- mal humerus and distal radius. As a hinge joint, the el- sults with casting for minimally displaced fractures, and bow has a poor tolerance for coronal plane deformities with closed reduction and percutaneous pinning for all and has a particular propensity for loss of motion. These type II and III flexion injuries. factors help to explain the disproportionate number of medical liability claims and the anxiety related to pedi- Treatment atric elbow fracture treatment. The goal of treatment of a pediatric supracondylar hu- Initial evaluation of a child with an injured elbow merus fracture is to restore alignment to a position should begin with a general examination and a search where there is no varus malalignment and the anterior for other sites of injury. Next, the involved upper ex- humeral line intersects the capitellar ossification center. tremity should be examined carefully for the point of Reduction and stabilization should be done without maximal tenderness in the area with maximum swelling. causing iatrogenic nerve injury or using elbow hyper- Any upper extremity deformity or a break in the skin flexion to a degree that will compromise distal perfu- integrity should be noted. Because of the high preva- sion. The use of a long arm cast for 3 weeks is satisfac- lence of neurovascular injuries, a careful neurovascular tory treatment for type I fractures, and for type II examination, including a check of the anterior in- fractures in which the anterior humeral line intersects terosseous nerve, is essential. The carrying angle of the the capitellar ossification center and Baumann’s angle is uninjured side should be noted, especially in a child acceptable. Closed reduction and percutaneous pinning with a supracondylar humerus fracture. is indicated for any fracture that does not meet these conditions. The trend toward pinning most type II and Radiographic evaluation should include the bones III supracondylar humerus fractures has dramatically and joints above and below the site of injury. The pres- reduced the incidence of clinically important malunions. ence of a posterior fat pad is an important sign of a pos- Because the technique of reduction and hyperflexion of sible occult elbow fracture. Radiographs should be stud- the elbow is now avoided, Volkmann’s ischemic contrac- ied closely for signs of a secondary injury. ture is rare. Supracondylar Fractures Initial evaluation includes a careful neurologic and vascular examination and AP and lateral radiographs of Supracondylar fractures, which represent 60% of elbow the distal humerus, with separate views of the entire fractures in children, are classified based on the extent forearm to check for associated injuries. The urgency of and direction of the displacement of the distal fragment; surgery was analyzed in a recent study of 158 well- 98% are extension injuries. The modified Gartland clas- sification system is used to describe the extent of injury. American Academy of Orthopaedic Surgeons 705

Elbow: Pediatrics Orthopaedic Knowledge Update 8 Figure 1 Two pinning techniques for displaced supracondylar humerus fractures are chemia is rare. The absence of a palpable pulse is less cross pins (A) and divergent lateral entry pins (B). These techniques both have been important than the integrity of distal perfusion. An ini- shown to be clinically effective and equally stable to extension varus and valgus test- tial angiogram is not warranted because the location of ing. The lateral pins do not put the ulnar nerve at risk for injury. the injury is known to be the fracture site. When treat- ing a supracondylar humerus fracture without a palpa- perfused type III fractures. The authors found no corre- ble pulse, the first step is anatomic closed reduction with lation between delay to surgery and the complication percutaneous pinning. Usually, a pulse that can be de- rate. However, children with a type III supracondylar tected by Doppler ultrasonography will be present fracture that will be pinned should be admitted to the shortly after pinning. If this is the case, the fracture hospital and carefully monitored for signs of neurovas- should be splinted in 40° to 50° of flexion and the child cular compromise or compartment syndrome. should be admitted to the hospital for 24 hours of obser- vation. If the hand remains poorly perfused after ana- Before fracture reduction, any entrapped soft tissue tomic reduction and pinning, a vascular consultation is should be dislodged by gently milking the brachialis warranted. muscle and other soft tissue from the fracture site. The fracture is reduced and held in hyperflexion while per- Volkmann’s ischemic contracture is now a rare com- cutaneous pins are placed. Recent reports of iatrogenic plication. A recent study evaluated forearm compart- ulnar nerve injury from the use of a medial pin have fo- ment pressures in supracondylar humerus fractures in cused attention on using only lateral entry pins. Al- 29 children. Pressures in the deep volar compartment though cadaver models have not shown such a tech- were significantly more elevated than in other compart- nique to be as biomechanically stable as the use of ments and fracture reduction did not have an immediate crossed pins, lateral entry pinning combined with casting effect on pressures. Most importantly, the investigators has been shown to be clinically effective. In a recent found that compartment pressures rose with elbow flex- biomechanical study in a synthetic bone model, diver- ion greater than 90°. Also, deep volar compartment gent lateral pins had similar stability to crossed pins on pressures greater than 30 mm often existed without clin- tests of extension and on tests of varus and valgus align- ical symptoms and without the subsequent development ment, but not for axial stress (Figure 1). If there is con- of compartment syndrome. The orthopaedist should be cern for instability after placing two divergent lateral alert for forearm pain after a supracondylar humerus entry pins, a third lateral pin can be added. The fracture fracture, or for any indication of worsening pain (or an- fixation should be tested for stability after pinning by algesic requirements) in a patient after closed reduction moving the elbow through a range of flexion and exten- and percutaneous pinning. sion, and by carefully stressing the fracture in rotation and varus and valgus, before splinting or casting in 70° A neurologic deficit is noted in about 20% of pa- to 80° of elbow flexion. The percutaneous pins are re- tients with supracondylar humerus fractures. The ante- moved if radiographs show satisfactory callus at 3- to rior interosseous nerve is the most common site of 4-week follow-up. nerve injury in extension injuries. In the flexion supra- condylar pattern, the ulnar nerve is the most likely to be Neurovascular Compromise injured. Most nerve injuries associated with supracondy- lar humerus fractures will resolve within 6 months. If an Vascular compromise has been documented in about iatrogenic ulnar nerve injury is noted after use of a me- 10% to 20% of type III extension supracondylar hu- dial pin, some investigators have noted that no interven- merus fractures. In these injuries, the brachial artery can tion is warranted; satisfactory resolution of the injury sustain an injury ranging from a minor intimal tear to often occurs. However, most investigators believe that complete arterial disruption. Because there is a rich col- upon recognition, the offending medial pin should be lateral circulation around the elbow, complete distal is- removed and replaced to a safe position. Malunion The instability after reduction of severely displaced su- pracondylar fractures results from failure to obtain good apposition of the distal medial and lateral columns. There is posterior rotation of the distal fragment, then a tilt into varus. Although the deformity may become in- creasingly apparent as elbow extension is regained, the deformity does not truly worsen over time. Although cu- bitus varus was considered primarily a cosmetic prob- lem, studies have shown an increased incidence of ulnar neuropathy, late lateral condyle fractures, and postero- 706 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 60 Elbow: Pediatrics Figure 2 Lateral condyle stages of dis- placement. A, Type I: A fracture in which the fracture line does not completely cross the cartilaginous surface of the dis- tal humerus. B, Type II: A complete frac- ture of the cartilaginous surface without displacement from the joint. C, Type III: A complete fracture with displacement of the lateral condylar fragment. (Adapted with permission from Jakob R, Fowles J, Rang M, et al: Observations concerning fractures of the lateral humeral condyle in children. J Bone Joint Surg Br 1975;57: 430-436.) lateral rotatory instability with this condition. Most os- schner wires are placed to stabilize the fracture. The teotomy techniques and fixation strategies have been pins are removed at 4 weeks, followed by 2 additional described in small studies. A recent report describes the weeks of casting. Pins left in for longer than 4 weeks are use of an external fixator to stabilize the fragment after increasingly likely to lead to irritation or infection. A re- an oblique, incomplete medial opening wedge osteot- cent study evaluated the rate of healing in 55 patients omy. The complication rate for all techniques tends to with lateral condyle fractures. The authors found that be quite high. Currently, there is no clear standard tech- radiographic evidence of complete bony healing was not nique for the treatment of cubitus varus after a pediatric present until 6 weeks after injury, even in children be- supracondylar humerus fracture. tween 1 and 5 years of age. Lateral Condyle Fractures Lateral condyle fractures are one of the few types of fractures in children in which delayed union or non- Because lateral humeral condyle fractures in children union is not unusual. If open reduction to an anatomic involve both the joint and growth cartilage, they are as- realignment is done more than 3 weeks after injury, os- sociated with a host of complications including non- teonecrosis may result if extensive soft-tissue stripping union, malunion, loss of motion, osteonecrosis, and cubi- is performed to achieve the reduction. In a recent re- tus valgus. The most clinically valuable classification view of 11 children who had open reduction and inter- system involves stages of displacement (Figure 2). The nal fixation without soft-tissue stripping, none of the oblique radiograph is most helpful in assessing the ex- children had osteonecrosis. The authors recommended tent of displacement. A recently published study of the that nonunions with greater than 1 cm of displacement MRI evaluation of lateral condyle fractures with 0 to be fixed without soft-tissue stripping and without resto- 3 mm of displacement confirmed previous arthrogram ration to the anatomic position. It was found that de- studies and concluded that the stability of the fracture is spite fixation in a nonanatomic position, overall elbow related to the integrity of the cartilage hinge. Lateral alignment and range of motion were good. Late lateral condyle fractures with up to 2 mm of displacement can condyle nonunion is asymptomatic in some patients, be treated with casting and close observation. An AP, whereas others develop cubitus valgus and a delayed ul- lateral, and oblique radiograph of the distal humerus nar nerve palsy. Some authors have recommended a su- with the cast removed should be obtained after about pracondylar medial closing wedge osteotomy and trans- 5 days and again at about 2 weeks to ensure that there position of the ulnar nerve for symptomatic patients. is no progressive displacement. If displacement is seen, reduction and pinning is the recommended treatment. Medial Epicondyle Fractures Closed reduction and percutaneous pinning is the Fractures of the medial epicondyle account for 7% to preferred treatment for fresh fractures that are only dis- 11% of all pediatric elbow fractures. These fractures re- placed from 2 to 5 mm, are relatively stable, and can be sult from avulsion of the epicondyle by the flexor- reduced to the anatomic position. Open reduction and pronator muscles and medial collateral ligament during internal fixation is usually required in the treatment of valgus stress or elbow dislocation. In patients with el- lateral condyle fractures. The technique involves a stan- bow dislocation where spontaneous or manipulative re- dard lateral approach to the distal humerus with no pos- duction entraps the medial epicondyle in the joint, the terior dissection (the blood supply to the lateral condyle medial epicondyle ossification center may be obscured is posterior). An anatomic reduction is ensured both vi- by the distal humerus or mistaken as the trochlear ossi- sually and radiographically and two percutaneous Kir- fication center. Careful evaluation of radiographs is im- American Academy of Orthopaedic Surgeons 707

Elbow: Pediatrics Orthopaedic Knowledge Update 8 portant whenever a medial elbow injury is suspected nique was biomechanically equivalent to tension band in a child. wiring without requiring exposure of the fracture site. A recent review of 39 patients with pediatric olecranon Treatment recomendations for medial epicondyle fractures with a mean follow-up of 32 years found en- fractures are somewhat controversial. Reduction and couraging results. Poor results were seen in only three pin or screw fixation of fractures displaced more than 2 patients, two of whom had associated radial head frac- to 5 mm is recommended in three circumstances: if a tures. The presence of associated injury may be more medial epicondyle is entrapped in the joint; in a fracture important than the degree of displacement of the ole- with associated ulnar nerve dysfunction; or for displaced cranon fracture in determining outcome. fractures in children who place high physical demands on their elbow. The latter group is difficult to define; Proximal Radius Fractures however, gymnasts and throwing athletes are included. A recent study retrospectively reviewed the results (at Although not a common injury, fractures of the proxi- more than 30-year follow-up) of 42 patients with medial mal radius in children result in many complications. In epicondyle fractures displaced more than 5 mm. Pa- contrast to similar fractures in adults, however, fractures tients treated with cast immobilization had similar func- through the neck of the radius are more common than tional results to those treated surgically, although radio- radial head fractures. A variety of treatment algorithms graphic union was much more common in the group exist for radial neck fractures based on the degree of treated surgically. Those treated with excision did displacement. Radial neck fractures with less than 3 mm poorly. Based on these findings, the authors questioned of translation and less than 30° of angulation can be surgical treatment of fractures displaced as much as 15 treated with a brief period of immobilization for com- mm, and did not recommend primary surgical excision. fort, followed by early motion. More displaced or angu- lated fractures should be reduced. Closed reduction is Medial Condyle Fractures often successful; if it fails, reduction with the use of a percutaneous Kirschner wire manipulation can be done. True medial condyle fractures are rare, accounting for If these methods of reduction fail, and angulation is only 1% to 2% of pediatric elbow fractures. Diagnosis greater than 60°, open reduction should be performed. may be difficult in the young child, especially before the Fixation is usually achieved with the use of Kirschner appearance of the trochlear ossification center. How- wires across the fracture but not the joint. A similar al- ever, the fracture typically involves a metaphyseal bony gorithm was used to treat 24 patients in a recent study. fragment, clearly differentiating it from a medial epi- All of the fractures were reduced to less than 15° of an- condyle fracture. Treatment principles for medial gulation, and all patients had excellent functional and condyle fractures are similar to those for lateral condyle radiographic results at 14- to 25-year follow-up. fractures. Nondisplaced fractures may be treated with cast immobilization, whereas displaced fractures should Radial head fractures, unlike radial neck fractures, undergo closed or open reduction with internal fixation. are intra-articular and deserve anatomic alignment. Arthrography or MRI may be helpful in determining ar- Open reduction is often required to achieve this goal. ticular displacement and guiding the choice of treat- ment. A recent study of 21 patients with medial condyle Monteggia Fractures fractures showed that such fractures are associated with a high rate of complications, including delayed or Monteggia lesions include a fracture of the proximal missed diagnosis, osteonecrosis of the trochlea, non- ulna with a radial head dislocation. The ulnar fracture union, fixation failure, and significant elbow stiffness. also may be a plastic deformation. A Monteggia fracture should be suspected whenever an “isolated” ulna frac- Olecranon Fractures ture or radial head dislocation is seen. In a child, closed reduction of the ulna usually reduces the radial head, Olecranon fractures account for approximately 4% to and the fracture often can be treated with a long arm 6% of pediatric elbow fractures and are associated with cast. However, open reduction and internal fixation of other elbow fractures in up to 41% of patients. Olecra- the ulna is required when an anatomic reduction of the non fractures in children are similar to those in adults, ulna, radiocapitellar joint, and proximal radioulnar joint in that they are usually intra-articular and metaphyseal. cannot be obtained or maintained by closed methods. However, unlike in adults, many olecranon fractures in children are minimally displaced and suitable for closed Previous reports have discouraged attempted open immobilization. Fractures with more than 2 mm of artic- reduction of a chronic radial head dislocation with or ular displacement should be reduced and stabilized with without annular ligament reconstruction because of the internal fixation. A recent report described a new fixa- high rate of redislocation and other complications. A re- tion technique using a pin with a threaded tip and an cent study reviewed 22 patients treated for chronic post- adjustable locking device at the opposite end. This tech- traumatic radial head dislocation. The authors con- cluded that ulnar osteotomy to correct the malunion 708 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 60 Elbow: Pediatrics Figure 3 A schematic drawing of the distal humeral proximal radius and ulnar relationship in various pediatric elbow injuries. A, Normal elbow. B, Elbow dislocation. C, Lateral condyle fracture. D, Supracondylar fracture. E, Distal humeral epiphyseal separation. (Adapted with permission from Delee JC, Wilkins KE, Rogers LF, Rockwood CA: Fracture- separation of the distal humeral epiphysis. J Bone Joint Surg Am 1980;62:46-51.) was essential in treating missed Monteggia fractures, if a injuries. Noninvasive measures such as splinting and normal radial head contour remained. A similar report physical therapy are successful in many patients. The of 15 patients who underwent open reduction of chronic technique of open capsular release has been used exten- radial head dislocations and ulnar osteotomies found sively in adults; some authors have reported its use in good to excellent functional results in 12 patients, al- children. A report on elbow release in 13 adolescent pa- though most lost some degree of pronation postopera- tients with posttraumatic stiffness showed than an aver- tively. age increase of 54° was produced in the flexion exten- sion arc. Only one patient lost motion. Nine patients Transphyseal Distal Humerus Fractures (69%) achieved at least a 25° to 120° arc of motion. A recent review of 37 patients receiving similar treatment Displaced fractures through the distal humeral physis showed only a 25° to 30° improvement in arc of motion; can be difficult to diagnose. In the infant, the only sign a useful (30° to 130°) arc was achieved only in 46% of may be malalignment of the radial and ulnar shafts rela- patients. After an extended period of observation, surgi- tive to the distal humerus. This injury is often associated cal release can be a valuable tool in the treatment of with battered child syndrome (Figure 3). Ultrasound, stiffness after complex pediatric elbow injuries. The pa- MRI, arthrography, and stress radiographs can help clar- tient and family should be counseled regarding expected ify the diagnosis of a transphyseal fracture. Treatment is improvements in arc of motion. similar to that for supracondylar fractures. Floating Elbow Annotated Bibliography Ipsilateral fractures of the distal humerus and distal Supracondylar Fractures forearm are called pediatric floating elbow. Commensu- rate with the severity of the trauma is an increased risk Battaglia TC, Armstrong DG, Schwend RM: Factors af- of clinically significant swelling, neurovascular compro- fecting forearm compartment pressures in children with mise, and forearm compartment syndrome. In a recent supracondylar fractures of the humerus. J Pediatr study of 16 patients with a supracondylar humerus frac- Orthop 2002;22:431-439. ture and a displaced distal radius fracture, surgical fixation of both fractures to avoid the high rate of po- The authors measured the forearm compartment pressures tentially devastating complications (particularly com- of 29 children with a type II or III supracondylar humerus partment syndrome) was recommended. fracture. Pressures in the deep volar compartment were signif- icantly elevated compared with the pressure in other compart- Elbow Contractures ments. There were also significantly higher pressures closer to the elbow within each compartment. Fracture reduction did Although children are generally less prone to posttrau- not have an immediate effect on pressures. Most importantly, matic joint stiffness than adults, not all children develop flexion beyond 90° produced significant pressure elevation. normal or even functional range of motion after elbow The authors also found that pressures greater than 30 mm Hg may exist without clinical evidence of compartment syndrome. American Academy of Orthopaedic Surgeons 709

Elbow: Pediatrics Orthopaedic Knowledge Update 8 They concluded that to avoid unnecessary elevation of pres- The authors report on 25 instances of cubitus varus defor- sures, elbows should not be immobilized in greater than 90° of mity (average 15°) subsequent to a pediatric distal humeral flexion. fracture or congenital anomaly in 24 patients who developed posterolateral rotatory instability of the elbow two to three De Boeck H: Flexion-type supracondylar elbow frac- decades afterward. Surgery was performed on 22 limbs, and tures in children. J Pediatr Orthop 2001;21:460-463. only 3 limbs had persistent instability at 3-year follow-up. The authors propose that the repetitive external rotation torque on Twenty-nine children with a flexion-type supracondylar the ulna, resulting from the medial displacment of the me- humerus fracture were reevaluated with an average follow-up chanical axis, the olecranon, and the triceps line of pull, can of 6.3 years. Seven children with a flexion-type supracondylar stretch the lateral collateral ligament complex and lead to pos- humerus fracture were treated in a cast and 22 children with a terolateral rotatory instability in patients with cubitus varus displaced flexion-type fracture were treated with closed reduc- deformity. Surgical correction can relieve symptoms of insta- tion and percutaneous pinning. Good or excellent results were bility. noted in 86.2% of the patients. All patients were satisfied with the end result and had normal use of the elbow. This article re- Skaggs DL, Cluck MW, Mostofi A, Flynn JM, Kay RM: ports on a large number of relatively rare flexion-type supra- Lateral-entry pin fixation in the management of supra- condylar fractures and highlights the good results that can be condylar fractures in children. J Bone Joint Surg Am obtained without an open reduction, even in patients with dis- 2004;86:702-707. placed and unstable fractures. The authors reported on 124 consecutive Gartland types II Koch PP, Exner GU: Supracondylar medial open wedge and III supracondylar humerus fractures treated with two or osteotomy with external fixation for cubitus varus defor- three lateral entry pins. The only complication reported was a mity. J Pediatr Orthop B 2003;12:116-122. pin tract infection. There was no loss of reduction, cubitus varus, hyperextension, loss of motion, or iatrogenic nerve pal- The authors describe a technique in which an anterome- sies, and no additional surgeries. The authors concluded that dial approach and a medial opening wedge osteotomy with ex- the most important technical points for assuring fixation with ternal fixation are used to treat cubitus varus in children after lateral-entry pins were: separating the pins at the fracture site; a malunion and following a supracondylar humerus fracture. engaging the medial and lateral columns proximal to the frac- The mean valgus correction was 21.75°. At 2-year follow-up, ture and sufficient bone in both the proximal segment and the three of the four children had symmetric elbow alignment and distal fragment; and using three pins to provide additional sta- one had slight residual varus deformity. The authors concluded bility when necessary. that this is a good technique for treating cubitus varus defor- mity allowing correction of both valgus and flexion. Lateral Condyle Fractures Lee ST, Mahar AT, Meisen D, Newton PO: Displaced Cardona JI, Riddle E, Kumar SJ: Displaced fractures of pediatric supracondylar humerus fractures: Biomechani- the lateral humeral condyle: Criteria for implant re- cal analysis of percutaneous pinning techniques. moval. J Pediatr Orthop 2002;22:194-197. J Pediatr Orthop 2002;22:440-443. The authors reviewed 55 lateral condylar fractures treated This biomechanical study of different supracondylar pin- at their institution over a 10-year period, with special attention ning techniques used a pediatric synthetic bone model. The to the rate of healing of the fracture. They concluded that in authors concluded that divergent lateral pins had similar sta- 50 patients, the fracture was clinically and radiographically bility compared with cross pins in extension, varus, and valgus healed at 6 weeks. Four patients showed radiographic healing testing. In axial testing, cross pins were more stable. Divergent at 5 weeks and one patient at 4 weeks. lateral pins also had statistically greater stability than parallel lateral pins under varus and valgus loading. Horn DH, Herman MJ, Crisci K, Pizzutillo PD, MacEwan GD: Fracture of the lateral humeral fracture Leet AI, Frisancho J, Ebramzadeh, E: Delayed treat- condyle: Role of the cartilage hinge in fracture stability. ment of type 3 supracondylar humerus fractures in chil- J Pediatr Orthop 2002;22:8-11. dren. J Pediatr Orthop 2002;22:203-207. The authors studied 16 patients with a lateral condyle frac- A retrospective review of 158 patients with well-profused ture who had both radiographs and MRI. All unstable frac- type III supracondylar humerus fractures showed no correla- tures had complete fractures on MRI scans. Ten of the 12 pa- tion between an increase in time to surgical intervention and tients with radiographically stable injuries had incomplete the complication rate. The average time from injury to surgical fractures on MRI scans. The authors concluded that the stabil- treatment was 21.3 hours. ity of the lateral humeral condyle fractures is related to the in- tegrity of the cartilage hinge. O’Driscoll SW, Spinner RJ, McKee MD, et al: Tardy pos- Wattenbarger JM, Gerardi J, Johnston CE: Late open terolateral rotatory instability of the elbow due to cubi- reduction internal fixation of lateral condyle fractures. tus varus. J Bone Joint Surg Am 2001;83:1358-1369. J Pediatr Orthop 2002;22:394-398. 710 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 60 Elbow: Pediatrics The authors reviewed the records of 11 children who had a The authors describe a novel fixation technique for olecra- malunion or nonunion of a lateral condyle fracture treated non fractures in children. A pin with a threaded tip is inserted more than 3 weeks after injury and found no patients with os- antegrade across the fracture site, without opening the frac- teonecrosis. In fractures with greater than 1 cm of displace- ture. A locking device is placed proximally on the pin to pro- ment, the fragment position was minimally improved by surgi- vide compression. A biomechanical analysis found this tech- cal treatment, but final alignment and range of motion were nique as strong as tension band wiring. The authors good. The authors concluded that the risk of osteonecrosis recommended this new technique over tension band wiring with open reduction of lateral condyle fractures at greater because it obviates the need to expose the fracture site. than 3 weeks is reduced if no tissue is stripped off the fracture fragment posteriorly. Even children without an anatomic re- Proximal Radius Fractures duction had functional arms and little or no pain. Malmvik J, Herbertsson P, Josefsson PO, Hasserius R, Medial Epicondyle Fractures Besjakov J, Karlsson MK: Fracture of the radial head and neck of Mason types II and III during growth: A Farsetti P, Potenza V, Caterini R, Ippolito E: Long-term 14-25 year follow-up. J Pediatr Orthop B 2003;12:63-83. results of treatment of fractures of the medial humeral epicondyle in children. J Bone Joint Surg Am 2001;83-A: Twenty-four patients with angulated radial head and neck 1299-1305. fractures during childhood were evaluated at a mean follow-up of 19 years. Two patients ultimately required radial The authors retrospectively reviewed 42 patients with me- head excision. Of the remainder, all but three patients had re- dial epicondyle fractures that were displaced more than 5 mm. ceived closed treatment. All patients had less than 15° of an- Nineteen patients were treated with cast immobilization with- gulation after primary treatment. Nineteen patients had no out reduction, 17 underwent open reduction and internal fixa- pain at follow-up, although elbow flexion was typically limited tion, and 6 patients had fragment excision. The functional re- compared with the uninjured side. sults at 30-year follow-up were identical for the first two groups, but worse for the excision group. The authors argue Waters PM, Stewart SL: Radial neck fracture nonunion that nonsurgical treatment is as effective as open reduction in children. J Pediatr Orthop 2001;21:570-576. and internal fixation for fractures with displacement of more than 5 mm. The authors describe nine children with radial neck non- unions; eight had associated elbow injuries. Eight children un- Medial Condyle Fractures derwent open reduction and fixation, and one had repeated closed reduction attempts with percutaneous fixation. In each Leet AI, Young C, Hoffer MM: Medial condyle fractures case, fixation failed and led to loss of reduction. Four patients of the humerus in children. J Pediatr Orthop 2002;22:2-7. were pain free, but all had restriction of motion. Secondary open repair of the nonunion did not guarantee good func- The authors reviewed a series of 21 children with medial tional outcome. condyle fractures. MRI was used to make the diagnosis or as- sess displacement in four children. Of the nine patients with Monteggia Fractures displaced fractures that were treated surgically, four had com- plications, including two patients who lost reduction and re- Horii E, Nakamura R, Koh S, Inagaki H, Yajima H, Na- quired revision with open reduction and internal fixation. Of kao E: Surgical treatment for chronic radial head dislo- the 12 patients who were treated in a cast, 2 developed non- cation. J Bone Joint Surg Am 2002;84-A:1183-1188. unions and 1 developed osteonecrosis of the trochlea. Almost half of the children had some impairment in range of motion. The authors reviewed 22 patients treated for chronic post- traumatic radial head dislocation. Thirteen patients underwent Olecranon Fractures open reduction without ulnar osteotomy, and seven had redis- location of the radial head. In a subsequent group of nine pa- Caterini R, Farsetti P, D’Arrigo C, Ippolito E: Fractures tients who had an ulnar osteotomy, the radial heads of two pa- of the olecranon in children: Long-term follow-up of 39 tients were subluxated at follow-up. Both patients had radial cases. J Pediatr Orthop B 2002;11:320-328. head abnormalities preoperatively. The authors concluded that ulnar osteotomy to correct malunion is essential in treating Thirty-nine patients with olecranon fractures in childhood missed Monteggia fractures if a normal radial head contour were followed at a mean of 32 years. Thirty-four patients had remains. good results and three had poor results. All had minimally dis- placed olecranon fractures and other associated fractures. Ar- Kim HT, Park BG, Suh JT, Yoo CI: Chronic radial head thritis was rare. The authors concluded that associated injuries dislocation in children: Part 2. Results of open treatment may be a stronger predictor of outcome than the degree of and factors affecting final outcome. J Pediatr Orthop displacement in patients with olecranon fractures. 2002;22:591-597. Gicquel P, Maximin MC, Boutemy P, et al: Biomechani- The authors describe 15 cases (14 patients) of open reduc- cal analysis of olecranon fracture fixation in children. tion and reconstruction of chronic radial head dislocations, 12 J Pediatr Orthop 2002;22:17-21. of which were posttraumatic. Results were classified as excel- lent in 10 elbows, good in 2, fair in 2, and poor in 1. One pa- American Academy of Orthopaedic Surgeons 711

Elbow: Pediatrics Orthopaedic Knowledge Update 8 tient developed a radioulnar synostosis, and 10 lost some de- Bernstein SM, McKeever P, Bernstein L: Percutaneous gree of pronation postoperatively. All radial heads in the reduction of displaced radial neck fractures in children. posttraumatic patients remained reduced at follow-up. The au- J Pediatr Orthop 1993;13:85-88. thors argue that the results of their series should encourage at- tempts at reducing chronically dislocated radial heads, espe- Cramer KE, Green NE, Devito DP: Incidence of ante- cially in posttraumatic patients. rior interosseous nerve palsy in supracondylar humerus fractures in children. J Pediatr Orthop 1993;13:502-505. Floating Elbow Culp RW, Ostermann AL, Davidson RS, Skirven T, Bora Ring D, Waters PM, Hotchkiss RN, Kasser JR: Pediatric FW Jr: Neural injuries associated with supracondylar floating elbow. J Pediatr Orthop 2001;21:456-459. fractures of the humerus in children. J Bone Joint Surg Am 1990;72:1211-1215. The authors reviewed a series of 16 patients with pediatric floating elbow injuries. All but one patient’s supracondylar hu- Flynn JC: Nonunion of slightly displaced fractures merus fracture was treated with pin fixation. In 10 patients, the of the lateral humeral condyle in children: An update. distal forearm fractures were treated with closed reduction J Pediatr Orthop 1989;9:691-696. and cast immobilization. Of these 10 patients, 2 developed compartment syndrome with 1 patient having a subsequent Foster DE, Sullivan JA, Gross RH: Lateral humeral Volkmann ischemic contracture. An additional 4 of these 10 condylar fractures in children. J Pediatr Orthop 1985;5: patients required cast removal because of excessive swelling 16-22. and impending compartment syndrome. The remaining six pa- tients were treated with pin fixation of their distal forearm Fowles JV, Slimane N, Kassab MT: Elbow dislocation fractures, and were not placed in circumferential casts. None with avulsion of the medial humeral epicondyle. J Bone developed compartment syndrome. The authors recommended Joint Surg Br 1990;72:102-104. surgical treatment of all fractures in this injury pattern to avoid the high rate of potentially devastating complications as- France J, Strong M: Deformity and function in supra- sociated with cast immobilization. condylar fractures of the humerus in children variously treated by closed reduction and splinting, traction, and Elbow Contractures percutaneous pinning. J Pediatr Orthop 1992;12:494-498. Bae DS, Waters PM: Surgical treatment of posttraumatic Gaddy BC, Strecker WB, Schoenecker PL: Surgical elbow contracture in adolescents. J Pediatr Orthop 2001; treatment of displaced olecranon fractures in children. 21:580-584. J Pediatr Orthop 1997;17:321-324. The authors describe 13 adolescents who had elbow capsu- Garbuz DS, Leitch K, Wright JG: The treatment of su- lar release for posttraumatic stiffness. An average increase of pracondylar fractures in children with an absent radial 54° was achieved in the flexion-extension arc. Nine patients pulse. J Pediatr Orthop 1996;16:594-596. (69%) achieved at least a 25° to 120° arc of motion; one pa- tient lost motion. The authors expressed enthusiasm for surgi- Keenan WN, Clegg J: Variation of Baumann’s angle with cal release of elbow contractures in adolescents. age, sex and side: Implications for its use in radiological monitoring of supracondylar fracture of the humerus in Stans AA, Maritz NG, O’Driscoll SW, Morrey BF: Oper- children. J Pediatr Orthop 1996;16:97-98. ative treatment of elbow contracture in patients 21- years of age or younger. J Bone Joint Surg Am 2002;84- Kissoon N, Gapin R, Gayle M, Chacon D, Brown T: A:382-387. Evaluation of the role of comparison radiographs in the diagnosis of traumatic elbow injuries. J Pediatr Orthop The authors describe surgical elbow releases in 37 patients 1995;15:449-453. younger than 21 years of age. Twenty-eight elbow contractures were posttraumatic. An average increase of only 25° to 30° of Lincoln TL, Mubarek SJ: Isolated traumatic radial head motion was obtained in the flexion-extension arc, regardless of dislocation. J Pediatr Orthop 1994;14:454-457. the etiology of the contracture. Fewer than half of the patients achieved a flexion extension arc of greater than 30° to 130°. Pirone AM, Graham HK, Krajbich JI: Management of The authors warn of the limited gains that can be expected displaced extension-type supracondylar fractures of the from elbow releases in children compared with those in adults. humerus in children. J Bone Joint Surg Am 1988;70:641- 650. Classic Bibliography Roye DP Jr, Bini SA, Infosino A: Late surgical treat- Archibeck MJ, Scott SM, Peters CL: Brachialis muscle ment of lateral condylar fractures in children. J Pediatr entrapment in displaced supracondylar humerus frac- Orthop 1991;11:195-199. tures: A technique of closed reduction and report of ini- tial results. J Pediatr Orthop 1997;17:298-302. 712 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 60 Elbow: Pediatrics Sabharwal S, Tredwell SJ, Beauchamp RD, et al: Man- angle: An aid in assessment of supracondylar fractures. agement of pulseless pink hand in pediatric supracondy- J Pediatr Orthop 1992;12:636-639. lar fractures of the humerus. J Pediatr Orthop 1997;17: 303-310. Zionts LE, McKellop HA, Hathaway R: Torsional strength of pin configuration used to fix supracondylar Williamson DM, Coates CJ, Miller RK, Cole WG: Nor- fractures of the humerus in children. J Bone Joint Surg mal characteristics of the Baumann (humerocapitellar) Am 1994;76:253-256. American Academy of Orthopaedic Surgeons 713



Chapter 61 Forearm, Wrist, and Hand: Pediatrics Peter M. Waters, MD Alexander D. Mih, MD Cerebral Palsy muscular blockade injection. Injections into the prona- tor, flexor carpi ulnaris, and adductor pollicis muscles Deformities of the forearm, wrist, and hand, limited are most often performed. Aggressive therapy should be function, and decreased sensibility are common in pa- used to stretch agonistic muscle-tendon units and tients with cerebral palsy. Limited motor function occurs strengthen antagonists. Antibody formation to botuli- with poor release and grasp function resulting from num toxin will limit its effectiveness in certain patients. flexor spasticity and contractures, combined with the ef- fects of weak extension of the fingers and wrist. Limited In patients with cerebral palsy, surgery improves pinch from thumb-in-palm deformity occurs because of level of function and cosmesis in the hemiplegic patient, intrinsic adductor and flexor spasticity and contractures. and ease of nursing care in the patient with quadripare- Discriminatory sensibility is deficient in more than 50% sis while lessening the risk of skin breakdown. The best of these children. Poor voluntary control of the upper surgical candidates are patients with hemiplegia and extremity limits functional placement of the hand in good voluntary control, sensibility, and motivation. The space; many of these children have visual and cognitive principle of surgery is to correct muscle imbalance by abnormalities that further impair hand function. At best, lengthening or releasing tight, spastic muscles and aug- most patients with cerebral palsy have assistive hand menting weak, stretched muscles by tendon transfers function. and tenodesis procedures. Unstable joints need to be stabilized by soft-tissue or arthrodesis procedures to Upper extremity classification systems for patients maximize outcome of tendon reconstruction. The pa- with cerebral palsy have been used to assess function. tient and family must understand that surgery will not The House classification of function has nine levels ex- alleviate all functional deficiency or repair all cosmetic tending from 0 (no use of the extremity) to 8 (complete defects of the hand. Even the best outcome will still re- spontaneous use). In this schema, the nine levels are fur- sult in deficiencies of function, cosmesis, and sensibility. ther classified into four subgroups based on patient However, in properly selected patients, surgery will function: no use (level 0), passive assist (levels 1 to 3), clearly improve function and patient satisfaction. active assist (levels 4 to 6), and spontaneous use (levels 7 and 8) (Table 1). Because spasticity varies with stress, Forearm hyperpronation significantly limits hand growth, and central nervous system changes, it may be function in patients with hemiplegia. Release or rerout- difficult to accurately define a patient’s level of function ing of the pronator teres through the interosseous mem- based on any single observation. Surgical planning and brane is effective in improving function. Transfer of the outcome assessment should be based on the level of flexor carpi ulnaris to the dorsal wrist by rerouting function determined preoperatively and postoperatively. around the ulna also has been shown to provide some Surgery will not create a normal hand but will improve degree of active supination. By improving voluntary assistive function and cosmesis. The goals of surgery control of forearm rotation, hand function increases. need to be realistic and obtainable. Wrist and finger flexion deformity is common in pa- Treatment tients with hemiplegia. The flexor carpi ulnaris is usually the major deforming force resulting in wrist flexion. In broad terms, treatment options include observation Transfer of the flexor carpi ulnaris to the wrist extensors of the patient’s growth and development, use of therapy alleviates the deformity and improves wrist extension (including splints), consideration of the need for injec- and finger tenodesis into flexion. Simultaneous muscu- tions (such as phenol or botulinum toxin), and surgical lotendinous lengthening of the finger flexors are neces- reconstruction of the forearm, wrist, and hand. Botuli- sary if the extrinsic finger flexors are tight in neutral num toxin is currently the most common form of neuro- wrist position; otherwise, the patient will develop a dis- abling clenched fist postoperatively. Z-lengthenings, su- American Academy of Orthopaedic Surgeons 715

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 Table 1 | House Classification for Hand Function in struction, and resection of the motor branch of the ulnar Patients With Cerebral Palsy nerve. The lateral band rerouting procedure provides both intrinsic and extrinsic rebalancing and is effective Level Designation Activity Level in correcting swan neck deformities. 0 Does not use Does not use Patients with cerebral palsy who have disabling dy- namic spasticity and fixed contractures of the wrist and 1 Poor passive assist Uses as stabilizing weight only hand benefit from surgical reconstruction. Often the more severely affected patients (House level 0 through 2 Fair passive assist Can hold onto object placed 2) respond best to musculotendinous lengthenings, teno- desis, and joint stabilization procedures. Patients with in hand more functional ability (House levels 3 through 6) im- prove with dynamic tendon transfers and releases. 3 Good passive assist Can hold onto object and Arthrogryposis stabilize it for use by other Infants with classic arthrogryposis (amyoplasia) often hand have stiffness and weakness of all joints and muscles of the upper extremity. Elbow extension, forearm prona- 4 Poor active assist Can actively grasp object and tion, wrist palmar flexion, ulnar deviation, finger flexion, and thumb-in-palm contractures are typical. Absence of hold it weakly biceps antigravity strength is common and limits the ability to place the hand near the face. Adaptive mecha- 5 Fair active assist Can actively grasp object and nisms are necessary for function. Children with arthro- gryposis often have incomplete syndactyly of all web stabilize it well spaces. Contracture of the first web space is usually functionally significant. Patients usually have marked in- 6 Good active assist Can actively grasp object and trinsic muscle weakness. manipulate it against other hand 7 Spontaneous use, partial Can perform bimanual activi- ties easily and occasionally uses the hand spontaneously 8 Spontaneous use, complete Uses hand completely inde- pendently without reference to the other hand (Reproduced with permission from Waters PM, Van Hest A: Spastic hemiplegia of the upper extremity in children. Hand Clin 1998;14:119-134.) perficialis to profundus flexor tendon transfers, and Treatment bony procedures are reserved for patients with severe contractures and limited function (usually found in the Initial treatment involves passive range-of-motion ther- patient with quadriparesis). apy and nighttime splinting to improve joint motion and digital strength. The condition of many children im- Thumb-in-palm deformity limits dynamic pinch and proves with growth and therapy over the first several grasp and makes hygiene difficult because of severe years of life. At the elbow, triceps V-Y lengthening and contractures. Static contractures are corrected with web posterior capsulectomy are performed at 18 months to 3 space Z-plasty and adductor releases. At times, the static years of age if passive elbow flexion of approximately contractures include the flexor pollicis longus and 90° does not occur. The wrist palmar flexion contracture brevis; these muscles will need to be appropriately is treated with both soft-tissue and bony procedures. A lengthened or released. Dynamic rebalancing is per- flexor carpi ulnaris release with lengthening or transfer formed with tendon transfers to weak abductors and ex- to the wrist extensors is performed in conjunction with a tensors of the thumb. There are many possible donor dorsal carpal closing wedge osteotomy. muscles including the palmaris longus, flexor carpi radi- alis, and brachioradialis. The recipient tendons include The thumb-in-palm contracture is treated with a the extensor pollicis brevis and longus and the abductor Z-plasty syndactyly release. Care must be taken not to pollicis longus. The metacarpophalangeal joint needs to overrelease the adductor. Transfers for thumb abduction be stable postoperatively. In most patients, stability is and extension are predominantly tenodesis procedures achieved by muscle rebalancing. On occasion, a capsul- because of the limited strength of the donor muscles. odesis or arthrodesis procedure will be needed. Children with arthrogryposis will have permanent Some patients with cerebral palsy have disabling limited motion and strength in their arms and hands. swan neck deformities. If the fingers at the proximal in- Because of their high level of intelligence, these children terphalangeal joint lock and hyperextend more than 40° often are quite functionally adaptive. and lock, limited grasp and pain may result. Multiple surgical procedures have been advised, including flexor Forearm and Wrist Trauma digitorum superficialis tenodesis, intrinsic muscle slide, lateral band rerouting, spiral oblique ligament recon- Epidemiology and Prevention Updates In a longitudinal study from New Zealand, it was deter- mined that 51% of boys and 40% of girls will experi- ence a single fracture by 18 years of age. The most com- 716 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics mon fracture sites, the wrist and forearm, accounted for Figure 1 A radiograph showing intramedullary fixation of a diaphyseal radius and 24% of all fractures. It was also found that 23% of boys ulna fracture. The ulnar pin is inserted proximally and the radial pin is inserted distally. and 16% of girls had more than one fracture before age 18 years. In a population-based study from Wales, it was bones in children are much less common. Scaphoid frac- noted that there was a seasonal variation in forearm and ture is the most common carpal bone fracture; however, wrist fractures in children and adolescents. The inci- it accounts for only 0.45% of all upper extremity frac- dence of such fractures markedly increased in spring tures in children. and summer, as did the severity of fracture. Twenty- three percent of patients with fractures required hospi- Fractures of the Diaphyseal Radius and Ulna tal admission in the spring and summer compared with only 10% of patients who had fractures during the win- Diaphyseal fractures are classified as plastic deforma- ter months. In a population-based, case control study tion, buckle or torus, greenstick or incomplete, and com- from Wales, a significant decrease in bone mass (mea- plete. Approximately 50% of diaphyseal fractures are sured by dual-energy x-ray absorptiometry and metacar- greenstick and most occur in children younger than 8 pal morphometry) was found in children age 9 to 16 years of age. The purpose of closed reduction is to cor- years, with wrist and forearm fractures compared with a rect the malrotation first, then the malangulation. control group. Postural balance scores were noted to be significantly poorer in patients with high body weight Complete fractures are more common in preadoles- and a history of previous forearm fracture compared cent and adolescent patients and tend to be unstable; with a control group with normal body weight. The in- these fractures often require internal fixation. There is creased body mass index and poor balance appear to an increased incidence of loss of reduction. More re- contribute to the increased risk of forearm fracture in cently, unstable diaphyseal forearm fractures have been these patients. treated with intramedullary fixation. Elastic nails or Kir- schner wires can be placed percutaneously after success- Participants in specific sports such as snowboarding, ful closed reduction. The ulnar pin is passed from proxi- horseback riding, and soccer (goal keeping) were noted mal to distal, while the radial pin is placed from distal to to have an increased risk of wrist fractures. In a retro- proximal with the entry site proximal to the distal radial spective review of skiers and snowboarders from Japan, physis (Figure 1). Open reduction is indicated for irre- there was an increased incidence of upper limb injuries, ducible fractures; unstable fractures, especially in the ad- particularly elbow dislocations and wrist fractures, in olescent patient; displaced segmental fractures; fractures those who participated in snowboarding. In a random- associated with unstable Monteggia, Galeazzi, or supra- ized controlled study of snowboarders in Norway, it was condylar fractures; refracture; and for patients with a noted that wrist guards significantly lowered the inci- dysvascular limb. dence of wrist injuries without increasing the risks for more proximal fractures or dislocations. Because of the Fractures of the Distal Radius and Ulna increased risk of head and wrist injuries in horseback riding, and the decrease in severity and number of head Metaphyseal Fractures injuries with the use of protective headgear, it has been Seventy-five percent to 84% of pediatric forearm frac- proposed that wrist protectors may be of benefit in this tures involve the distal radius. Most of these radial frac- sport as well. tures are metaphyseal and are associated with metaphy- seal fractures of the ulna. Nondisplaced metaphyseal Ligamentous laxity correlates with the site of the torus fractures can be treated with brief immobilization. fracture. Patients with hyperlaxity are more likely to Studies indicate that removal of the splint at home was have a supracondylar humerus fracture after a fall, more satisfactory for families than return for doctor- whereas children with less laxity are more likely to sus- supervised removal; the clinical outcome was the same. tain distal radius fractures. In a study of distal radius fractures in young soccer goalkeepers, the size of the ball correlated with the risk of a distal radius fracture. Forearm and Wrist Fractures Fractures of the forearm are the most common long bone fractures in children, accounting for 45% of all childhood fractures and 62% of upper extremity frac- tures. Approximately 75% to 84% of these forearm fractures occur in the distal third of the bone; 15% to 18% in the middle third; and less than 5% in the proxi- mal third. Injuries to the distal radioulnar joint or carpal American Academy of Orthopaedic Surgeons 717

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 Although closed reduction and long arm cast immo- Figure 2 A displaced distal radius metaphyseal fracture treated with percutaneous bilization is indicated for fractures with greater than 10° fixation. Care must be taken to avoid the radial sensory nerve and, if possible, the of malalignment, several studies indicate a high inci- distal radial physis, with the radial pin. Care must be taken to avoid the extensor dence (up to 34%) of loss of reduction. Percutaneous tendons with the ulnar pin. pin fixation avoids the need for rereduction of difficult distal radius fractures but does carry the risks associated with anesthesia, pin placement, possible infection, and limited scarring. Two separate randomized trials of pin- ning compared with cast immobilization indicated that pinning significantly reduced the risk of loss of reduc- tion requiring remanipulaton; however, long-term clini- cal outcome was the same for both groups of patients. Pinning is reasonable for fractures with initial angula- tion greater than 30° and displacement more than 50% of the diameter of the radius. Remodeling of malunited fractures in the flexion/extension plane will occur and, to a lesser extent, remodeling will also occur in the ra- dial deviation/ulnar deviation plane if sufficient gravity remains. Rotational malunion will not remodel. Percutaneous pinning is clearly indicated for frac- tures associated with neurovascular compromise and significant soft-tissue swelling, and with concomitant fractures of the elbow (floating elbow) because of the increased risk for development of compartment syn- drome in these patients. A smooth Kirschner wire is in- serted obliquely from distal to proximal, starting in the radial metaphysis just proximal to the physis. Care must be taken to avoid the radial sensory nerve with inser- tion. This procedure may be done with a 5- to 10-mm in- cision and clearing of the pin tract. A second, crossing Kirschner wire can be inserted from between the fourth and fifth dorsal extensor compartments while avoiding the extensor tendons (Figure 2). Distal Radius Physeal Fractures patients with distal radius fractures and 50% of patients Most distal radius physeal fractures are Salter-Harris with distal ulna fractures had a symptomatic growth dis- type II injuries that occur in adolescents. Displacement crepancy greater than 1 cm. In addition, 38 asymptomatic is typically dorsal with apex volar angulation. An atrau- patients had growth discrepancies between 2 to 9 mm. Pa- matic closed reduction and long arm cast immobiliza- tients with redisplacement or late presentation should not tion is indicated for fractures with greater than 10° of undergo a repeat reduction after 7 days to avoid iatro- malangulation. The most significant complications are genic physeal arrest. Late open reduction should be associated with future growth arrest and acute neu- avoided for the same reason. Because these fractures dis- rovascular compromise. The incidence of associated place in the plane of motion of the wrist joint and are jux- nerve injuries is approximately 8%. Studies indicate that taphyseal, there is tremendous potential for remodeling patients with signs or symptoms of median nerve injury of a malunion in the younger adolescent patient. If the at the time of presentation would be best treated by malunion does not remodel with growth, a dorsal opening percutaneous pin fixation rather than cast immobiliza- wedge osteotomy with bone graft and internal fixation tion to lessen the risk of forearm compartment syn- may be needed for the skeletally mature patient with drome, acute carpal tunnel syndrome, or median neu- greater than 10° apex dorsal malangulation. Patients with ropathy. There is limited evidence of a significant risk of displaced physeal fractures should be examined for 1 to 2 growth arrest with the use of smooth, small diameter years after the fracture occurrence to rule out a growth pins. The pins should be removed at 3 to 4 weeks post- disturbance. If a radial growth arrest occurs, the contin- operatively to lessen the risk of growth arrest. ued ulnar growth can lead to distal radioulnar joint incon- gruity, ulnocarpal impaction, and a triangular fibrocarti- Long-term follow-up (average, 25.5 years) of 157 pa- lage tear (Figure 3). tients with distal radius and ulna physeal fractures who were treated with closed reduction showed that 4.4% of 718 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics Figure 3 A, Radiograph shows distal radial physeal arrest after repetitive closed reductions of a Salter-Harris type II fracture. Note the ulnar overgrowth with open physis and the radial growth arrest. B, Clinical photograph of the patient showing the deformity resulting in ulnar-carpal impaction. Hand Trauma displaced in extension and often malrotates. The sub- condylar fossa is obliterated, blocking interphalangeal Fractures to the pediatric hand account for approxi- flexion. If not properly recognized and treated, compli- mately one quarter of all childhood fractures and have cations of malunion and loss of motion occur. The sever- two peak periods of occurrence—in adolescence (from ity of this fracture is often underappreciated in the ur- sport-related activities) and in infancy (from crush inju- gent care setting. Treatment is with either closed ries). Most of these fractures are nondisplaced, nonphy- reduction and percutaneous pinning or by open reduc- seal injuries that do not have long-term consequences. tion and internal fixation. If open reduction is necessary, Physeal injuries account for up to 40% of finger frac- the collateral ligaments should not be dissected from tures. A Salter-Harris type II fracture of the small finger the distal fragment. This action increases the risk of os- proximal phalanx is the most common physeal injury. teonecrosis. Treatment for a late malunion includes os- Distal tuft and phalanx fractures are the most common teotomy, subchondral fossa reconstruction, or remodel- fractures in infants and children up to age 8 years; prox- ing. Remodeling of phalangeal neck malunions rarely imal phalanx fractures of the small finger are most com- occurs because of the significant distance from the phy- mon in the 9- to 12-year age group; and fifth metacarpal sis. neck fractures have the highest incidence in patients age 13 to 16 years. Most pediatric hand fractures heal within Osteochondral fractures in young children are often 2 to 3 weeks and have excellent functional outcomes re- challenging to treat. These fractures have a high risk of gardless of the type of treatment used. Malunions or nonunion, malunion, and osteonecrosis, which is particu- growth disturbances are rare. However, there is a subset larly true in crush injuries to the middle phalanx that al- of pediatric hand fractures with comminution, severe ter the local blood supply. The fracture is intra-articular, displacement, and intra-articular and condylar involve- generally displaced, and requires anatomic reduction for ment, which will heal poorly if not recognized and ap- a successful outcome. Most often, the fracture needs to propriately treated. These fractures account for 12% to be treated aggressively with open reduction. Bone grafts 20% of pediatric fractures in most studies. may be necessary to maintain articular congruity and prevent collapse. Even with a well-performed open re- Problematic Hand Fractures duction, complications from osteochondral fractures can occur in young children. Phalangeal neck fractures are usually caused by crush injuries. As the child attempts to extract the affected In the adolescent, treatment of intercondylar frac- digit, the condyles become entrapped and a fracture oc- tures is similar to that given to adults. Anatomic reduc- curs in the subcondylar region. The condylar fragment is tion and pin fixation is necessary to restore the joint sur- face and to prevent loss of reduction. Open reduction is American Academy of Orthopaedic Surgeons 719

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 appropriate for fractures that are not suitable for closed excursion with wrist tenodesis serve as the basis for di- reduction, and can be performed with a volar, midaxial, agnosis of a flexor tendon laceration. If doubt exits, the or dorsal approach. Restoration of an anatomic joint wound should be explored with the patient under anes- lessens the risk of long-term arthritis, malalignment, and thesia. Repair of the tendon lacerations in zones I and loss of motion. II requires meticulous technique with fine sutures. Post- operative cast immobilization for 4 weeks is effective. The major complication of diaphyseal-level pha- langeal fractures is malrotation. Frequently, children will No differences have been found in total active mo- refuse to actively move the affected finger in the acute set- tion (TAM) between patients treated with early mobili- ting, thus preventing accurate assessment of digital align- zation protocols and those treated with cast immobiliza- ment. However, possible tenodesis of the wrist enables the tion for 4 weeks. If cast immobilization continues physician to assess malrotation and should be performed beyond 4 weeks, TAM may decrease by up to 40% by 6 on all phalangeal and metacarpal fractures regardless of weeks. There was no difference in the results in groups radiographic appearance. If closed treatment is chosen, a from 0 to 15 years of age. solitary finger should never be immobilized; it should be secured to the adjacent digits to prevent subsequent loss Two-stage reconstruction of unrecognized zone II of reduction. If the fracture is malrotated and unstable, a lacerations in children has poorer results than in adults, reduction pin or screw is necessary for stabilization. Al- with a higher rate of complications and a mean TAM of though malrotation is uncommon, it can result in a major only 140°. Better results are achieved with supervised complication if it is not discovered until after union takes rehabilitation. In a study on uncomplicated flexor polli- place. The malrotated digit impairs the function of the ad- cis longus tendon laceration repairs, long-term limited jacent digits secondary to overlap, and can only be cor- motion (> 30°) of the interphalangeal joint occurred in rected with osteotomy. one third of the patients. Short splint immobilization had a negative effect on outcome; however, zone of in- Scaphoid Fractures jury, an early mobilization program, or concurrent digi- tal nerve injury had no significant effect on long-term Distal pole scaphoid fractures in the skeletally imma- outcome. ture patient heal readily with cast immobilization with- out risk of nonunion or osteonecrosis. Scaphoid waist Amputations fractures are common in the adolescent age group. Re- cent studies have indicated that both adults and children The treatment of proximal, complete digital amputa- with clinical pain in the region of the scaphoid and nor- tions with replantation in children as young as 1 year of mal radiographs may benefit from MRI, the results of age is now standard. In children, the indication for re- which will alter treatment choices in a high percentage plantation is more liberal than in adult patients and in- of patients. Waist fractures carry the same risks of non- cludes cases of multiple digit, thumb, midpalm, hand, union and osteonecrosis in the child as they do in an and distal forearm amputations, as well as single digit adult. Open reduction, bone grafting, and internal fixa- amputations in zones I and II. Crush amputations tion should be used to treat an established nonunion in caused by compression from doors, heavy objects, or bi- a child. The epidemiology of scaphoid fractures contin- cycle chains have a peak incidence in children 5 years of ues to change; proximal pole fractures, nonunions, and age, whereas amputations caused by sharp objects occur osteonecrosis now have been described in adolescents. more commonly in adolescents. Digital survival rates Treatment with distal radial vascularized bone graft has from replantation range from 69% to 89% in pediatric been recommended for these unique complications. The studies. Indications that favor digital survival are ampu- treatment of acute scaphoid fractures, even nondis- tations resulting from sharp objects, patient body weight placed fractures, with percutaneous screw fixation is greater than 11 kg, more than one vein repaired, bone controversial. The complication rates in patients with shortening, interosseous wire fixation, and vein grafting acute scaphoid fractures who were treated with casting of arteries and veins. Vessel size generally exceeds 0.8 compared with those treated with screw fixation have mm in digital replants in children and is not a technical been statistically equivalent. problem for the skilled microvascular surgeon. Index and long finger replants have been more successful than Flexor Tendon Injuries small finger replants in children. A digital survival rate of 95% occurred in children if prompt reperfusion was Tendon Lacerations seen after arterial repair with at least one successful The diagnosis, surgical care, and postoperative rehabili- venous anastomosis. Neural recovery rates far exceed tation of a flexor tendon injury may be more difficult in those found in adult patients; return of two-point dis- a child than in an adult. Treatment is especially difficult crimination of less than 5 mm often occurs. Tenolysis in a toddler or preschool-age child who offers limited may be necessary after tendon repair. Growth arrest or cooperation. The presenting digital cascade and digital deformity is more common if there is a crush compo- 720 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics Table 2 | Classification of Congenital Upper Limb eries of more than 12,000 children have not found this Malformations condition to be present at birth, supporting the belief that it is not a true congenital condition. The child will I Failure of formation have a flexion deformity of the interphalangeal joint A Transverse arrest that may not be passively correctable. A compensatory B Longitudinal arrest hyperextension deformity at the metacarpophalangeal joint may also develop. A palpable nodule at the level of II Failure of differentiation (separation) the A1 pulley of the thumb, which appears to be caused III Congenital tumorous conditions by edema within the tendon, will also be present. IV Duplication V Overgrowth Spontaneous resolution occurs in a small number of VI Undergrowth patients. Nonsurgical treatment has been most popular VII Congenital constriction ring syndrome in Asia where a combination of splinting and passive VIII Generalized skeletal abnormalities motion has been shown to allow for correction in up to two thirds of affected patients. When the thumb does nent to the amputation. Microvascular toe to thumb not show any sign of spontaneous correction, A1 pulley transfer is a successful alternative to pollicization as release is indicated. This procedure may be performed treatment for a failed replant in a young child. by either transverse incision or a chevron type incision centered over the metacarpophalangeal joint. Longitudi- Congenital Upper Extremity Malformations nal incisions over this site have been shown to adversely affect range of motion and appearance. Long-term stud- The prevalence of congenital upper limb anomalies is 2 ies of trigger thumb release have found that although per 1,000 live births. Forty-six percent of these infants also recurrence of triggering is extremely rare, approxi- have another nonhand anomaly; bilateral hand anomalies mately 25% of the patients show some limitation in in- are found in more than 50% of these patients. Overall, terphalangeal joint motion compared with the unaf- boys are affected more than girls by a ratio of 3:2. Ad- fected thumb. No long-term functional deficits have vanced maternal age significantly increases the prevalence been noted with trigger thumb release. of congenital upper extremity malformations. Trigger Finger Recent advances in embryology have greatly im- proved the understanding of human limb development. Based on large population studies, trigger finger, like Growth factors influence the apical ectodermal ridge trigger thumb, has not been found at birth. Patients with and numerous genes influence the zone of polarizing ac- trigger fingers have a higher rate of spontaneous resolu- tivity and polarity. Genes responsible for specific defor- tion and an earlier age of onset than patients with trig- mities such as triphalangeal thumb have been identified ger thumbs. For those digits not showing spontaneous on specific chromosomes. Modern ultrasound tech- correction, abnormalities are found well beyond the A1 niques also have increased the rate of prenatal diagnosis pulley and may include abnormalities of the flexor digi- of these disorders and may lead to parental consultation torum sublimis tendon insertion and the A3 pulley. Sur- before birth. gical treatment of a trigger finger requires exploration of the digit well beyond the A1 pulley because almost During embryologic growth, the limb bud appears 26 50% of patients undergoing simple A1 pulley release days after fertilization. The final stage of upper extrem- will have residual triggering. ity development, separation of the ring and small digits, is completed by day 56. Events occurring at various Polydactyly stages of embryologic growth may have profound ef- fects on the ultimate appearance of the limb. Polydactyly occurs as an isolated disorder, in association with other malformations of the extremities, or as part Classification of a syndrome. It usually occurs sporadically but may be inherited with a mainly autosomal dominant inherit- The most commonly used classification system is that ance. Polydactyly is categorized as radial, central, or ul- proposed by the American Society for Surgery of the nar with the small finger the most commonly duplicated Hand and the International Federation of Societies for digit. Surgery of the Hand. This system includes eight catego- ries that are based on the proposed etiologic pathways Small finger duplication may occur as either a skin and are found in Table 2. tag or a fully developed digit including a fully formed metacarpal bone (Figure 4). The incidence of this disor- Trigger Thumb der has been reported as high as 1 in 300 births in the African American population and 1 in 3,000 in the Trigger thumb is one of the most common malforma- white population. In the African American population, tions in children. Two large studies of consecutive deliv- American Academy of Orthopaedic Surgeons 721

Forearm, Wrist, and Hand: Pediatrics Orthopaedic Knowledge Update 8 Table 3 | Thumb Duplication Level Description I Bifid distal phalanx II Complete duplication distal phalanx III Complete duplication distal phalanx, bifid proximal phalanx IV Complete duplication distal and proximal phalanges V Complete duplication distal and proximal phalanges, bifid metacarpal VI Complete duplication distal, proximal phalanges, and meta- carpal VII Triphalangeal thumb Figure 4 Small finger duplication, complete. this condition is rarely associated with any other type of Figure 5 Type IV thumb duplication, converging. malformation, whereas up to 30% of white children with small finger polydactyly will have underlying organ eral ligament, the preferred treatment is preservation of system disorders such as gastrointestinal or genitouri- the more ulnar digit, which in most patients is more nary malformations. Most patients with ulnar polydac- completely developed. Late deformities have been ob- tyly are treated with either ligation in the nursery or served as a result of instability of the interphalangeal simple excision. One recent study found a 23% compli- joints and eccentric insertions of the flexor and/or ex- cation rate following suture ligation; infection and in- tensor tendon. These deformities may have a radial in- complete removal were the most common complica- tions. Patients with ulnar polydactyly involving neurovascular structures in bone will require more so- phisticated reconstruction, which may include transfer- ence of hypothenar tendons and collateral ligament re- construction. Radial side polydactyly involving the thumb is classi- fied based on the level of duplication (Table 3) and ranges from a bifid distal phalanx to complete duplica- tion of metacarpals (Figure 5). Patients with malforma- tions involving the thumb tips may benefit from a combination type procedure with more proximal dupli- cations treated by excision of the radial digit and recon- struction of the retained ulnar digit. Simple excision produces significant complications of instability and stiffness; formal reconstruction of the duplicated digit including advancement of the thenar tendon and collat- eral ligament reconstruction should be performed. Be- cause of the difficulty in reconstructing the ulnar collat- 722 American Academy of Orthopaedic Surgeons

Orthopaedic Knowledge Update 8 Chapter 61 Forearm, Wrist, and Hand: Pediatrics sertion along the retained digit, allowing for a zigzag type of deformity later in life. Although long-term stud- ies show few functional problems with duplicate thumb reconstruction, a large percentage of patients report stiffness and/or instability at the interphalangeal joints. The triphalangeal thumb falls within the category of thumb duplication and is an autosomal dominant form of an inherited radial abnormality (Figure 6). It may ex- ist in combination with syndactyly. Complications asso- ciated with multiple level joint instability have led some physicians to recommend ablation of this digit when it is part of a radial side polydactyly. When seen in isolation, the triphalangeal thumb is best treated by deletion of the middle phalanx and temporary pin fixation of the resulting interphalangeal joint. Central polydactyly is a rare condition involving du- plication of the index, long, or ring digits. These digits often show incomplete duplication with frequent over- lapping of the duplicated digits. Most patients are best treated by deletion of these digits, which are often un- derdeveloped. Radial Head Dislocation Figure 6 Duplicate thumb, triphalangeal ulnar component. Congenital radial head dislocation is often asympto- may not be readily apparent until 18 months of age. In matic and may go undiagnosed until radiographs have patients with a deviation caused by this abnormal epi- been obtained for an injury. True congenital dislocations physeal plate, a portion of the plate should be removed may have a late diagnosis because of the frequency of and replaced by fat or other material. This technique bilateral involvement. Recent reports have suggested has been shown to successfully stop the abnormal devia- that open reduction and ligament repair or reconstruc- tion of the digit. In patients in whom treatment is de- tion may successfully reduce the radial head. Longer layed, treatment may require reversed wedge osteotomy term studies are needed to determine if the bony as a method to both correct deformity and arrest the ab- changes that include capitellar undergrowth, radial head normal epiphyseal growth. enlargement, and bowing may be prevented by open re- duction. Radial head reduction has not been as success- Constriction Ring Syndrome ful in patients with either radial or ulnar dysplasia and in patients older than 5 years of age at the time of sur- Constriction ring syndrome has been reported in up to 1 gery. in 10,000 births. Although the etiology of this disorder is not completely known, a similar disorder has been pro- In patients who are not evaluated until secondary duced in laboratory animals by creating a vascular insult bone changes have occurred, open reduction has not late in limb development. In these experiments, the loss been recommended. Radial head resection at adoles- of the epidermal layer causes coalescence of digits much cence remains a mainstay of treatment and has been like that seen in an untreated burn. Involvement of the shown to improve range of motion. Regrowth of the digits ranges from mild skin dimpling to complete ab- proximal radius has been reported after radial head re- sence of digits. Acral syndactyly is noted with coales- section and may cause secondary impingement and loss cence of digits at the tip combined with separation at of motion. Longitudinal Epiphyseal Bracket (Delta Phalanx) Delta phalanx may be found in isolation or within a digit affected by other disorders such as syndactyly (Fig- ure 7). In this condition the epiphyseal plate is oriented both transversely and longitudinally, forming a “C” shape. This abnormal epiphyseal plate may cause a sig- nificant deviation in digits that are operated on for other conditions, and may be undetected at the time of initial surgery. Studies have shown that this condition American Academy of Orthopaedic Surgeons 723