Netter Concise Orthopaedic Anatomy 2nd Edition

6 Hand • TENDONS Extensor zones of hand Flexor zones of hand I DIP joint T-I IP joint II Middle phalanx T-II Proximal phalanx III T-III MP joint III PIP joint T-IV Metacarpal I II II II T-I IV Proximal phalanx T-V CMC joint radial styloid II V MP joint III VI Metacarpal T-III VII Dorsal retinaculum IV VIII Distal forearm T-II V IX Mid and proximal forearm ZONE BOUNDARIES COMMENT FLEXOR TENDON ZONES I Distal to FDS Single tendon (FDP) injury. Primary repair. DIPJ contracture results if tendon short- insertion ened Ͼ1cm. Quadriga effect can also result II Finger flexor “No man’s land.” Both tendons(FDS, FDP) require early repair (within 7 days) and mo- retinaculum bilization. Lacerations may be at different locations on each tendon and away from III skin laceration. Preserve A2 & A4 pulleys during repair IV Palm Primary repair. Arterial arch & median nerve injuries common. V Carpal tunnel Must release & repair the transverse carpal ligament during tendon repair. Thumb I Wrist & forearm Primary repair (ϩ any neurovascular injury). Results are usually favorable. Distal to FPL Primary tendon repair. Rerupture rate is high. Thumb II insertion Primary tendon repair. Preserve either A1 or oblique pulley. Thumb III Thumb flexor Do not operate in this zone. Recurrent motor branch is at risk of injury. I retinaculum EXTENSOR TENDON ZONES II Thenar eminence III “Mallet finger.” Splint in extension for 6 wk continuously. DIP joint Complete lacerations: primary repair and extension splint. IV Middle phalanx Central slip injury. Splint in extension for 6 wk. If triangular ligament is also disrupted, V PIP joint lateral bands migrate volarly, resulting in “boutonniere finger” VI Primary repair of tendon (and lateral bands if needed), then extension splint VII Proximal phalanx Often from “fight bite.” Repair tendon and sagittal bands as needed. VIII MCP joint Primary repair and early mobilization/dynamic splinting. IX Metacarpal Retinaculum likely injured. Primary tendon repair, early mobilization. Wrist At musculotendinous jxn. Primary repair of tendinous tissue & immobilize Distal forearm Often muscle injury. Neurovascular injury high. Repair muscle & immobilize. Proximal forearm 190 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

A1 C1 TENDONS • Hand 6 Tendons of flex- Pulleys or digitorum A2 C2 A3 C3 A4 C4 A5 superficialis and profundus Volar plates (palmar ligaments) muscles (Synovial) tendinous sheath Anterior (palmar) views Superficial palmar Proper palmar digital nerves of thumb branch of radial artery and recurrent Common palmar digital artery branch of median Proper palmar digital arteries and nerves nerve to thenar Annular and cruciform parts of fibrous sheath muscles over (synovial) flexor tendon sheaths Ulnar artery and nerve Common palmar digital branches of median nerve (cut) Hypothenar muscles Common flexor sheath (ulnar bursa) 5th finger (synovial) tendinous sheath Insertion of flexor digitorum superficialis tendon Insertion of flexor digitorum profundus tendon STRUCTURE DESCRIPTION COMMENT Flexor tendon FLEXOR TENDON SHEATH sheath Pulleys Fibroosseous tunnel lined with tenosynovium Site of possible infection; check for Kanavel Protects, lubricates, and nourishes the tendon signs (see Disorders table) Vincula Volar plate (palmar Thickenings of sheath to stabilize tendons 5 A2 & A4 (over P1 & P2) most important; must be ligament) annular (A1[MCPJ], A3[PIPJ], A5[DIPJ] over intact to prevent “bowstringing” of tendons joints; A2, A4 over phalanges) 3 or 4 cruci- Tight A1 can cause a trigger finger ate pulleys A3 covers PIPJ volar plate: incise to access Within sheath, give vascular supply to ten- Vincula torn in type 1 FDP rupture (dysvascular), dons: 2 vincula (longa and brevia) preserved in types 2 & 3 rupture Thickening of volar capsule of interphalan- FDS & FDP tendons insert here to flex the PIP & geal joints DIP joints, respectively. Prevent hyperextension. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 191

6 Hand • JOINTS Posterior (dorsal) view Scaphoid Triquetrum Capitate Hamate Trapezium Capsule of 1st carpo- Dorsal carpometacarpal ligaments metacarpal joint Dorsal metacarpal ligaments Trapezoid 5 1 4 32 Metacarpal bones LIGAMENT ATTACHMENTS COMMENTS CARPOMETACARPAL Thumb • Saddle joint. Highly mobile, has both inherent bony and ligamentous stability. Prone to develop osteoarthritis • Primary movements: flexion, extension, adduction, abduction • Complex (combined) movements: opposition, retropulsion, palmar abduction, radial abduction/adduction Capsule Base of metacarpal to trapezium Surrounds joint and is a secondary stabilizer Anterior (volar) oblique Ulnar side of 1st metacarpal base to “Beak” ligament. Holds fragment in Bennett’s fx. tubercle of trapezium Primary restraint to subluxation. Injury can lead to osteoarthritis. Dorsal radial Dorsal trapezium to dorsal MC base Strongest. Dorsal and radial support. Torn in dorsal dislocation. 1st intermetacarpal Ulnar 1st MC base to radial 2nd MC Prevents 1st metacarpal from translating radially base Posterior oblique Trapezium to dorsal ulnar MC base Secondary stabilizer Ulnar collateral Volar ulnar trapezium to ulnar MC Limits abduction and extension base Radial lateral Radially on trapezium and MC base Under the APL tendon/insertion Finger • Gliding joints. 2nd & 3rd CMC have little motion, so minimal metacarpal fx angulation is acceptable b/c of immobility. 4th & 5th CMC have more anteroposterior motion, so more metacarpal fx angulation is acceptable b/c of mobility. Capsule Base of metacarpal to carpus Adds stability CMC ligaments Base of metacarpal to carpus Dorsal (strongest), volar, interosseous ligaments Intermetacarpal Between adjacent metacarpal bases Adds ulnar and radial stability to CMC joint 192 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Anterior (palmar) view JOINTS • Hand 6 Trapezium Pisiform Joint capsule Hook of hamate Collateral ligaments Palmar carpometacarpal ligaments Palmar metacarpal ligaments Cut margins of digital fibrous sheaths Deep transverse Flexor digitorum metacarpal ligaments superficialis tendons (cut) Volar plates (palmar ligaments) Flexor digitorum profundus tendons LIGAMENT ATTACHMENTS COMMENTS METACARPOPHALANGEAL Thumb • Diarthrodial joint. Motion: primary ϭ flexion & extension; secondary ϭ rotation, adduction, abduction Capsule Surrounds joint Secondary stabilizer dorsally. Taut in flexion Proper collateral Center of metacarpal head to Primary stabilizer. Taut in flexion, test in 30° flexion palmar proximal phalanx Ulnar collateral injured in “gamekeeper’s/skier’s” thumb Accessory collateral Palmar to proper collateral lig. Taut in extension. Test integrity in extension. Volar (palmar) plate Palmar metacarpal head to pal- Primary stabilizer in extension. Laxity in extension indi- mar proximal phalanx base cates injury to volar plate (ϩ/Ϫ accessory collateral lig.) Finger • Diarthrodial joint. Motion: primary ϭ flexion & extension (ROM 0-90°); secondary ϭ radial & ulnar deviation • Asymmetry of metacarpal head & collateral ligament origin result in “cam effect” (tight in flexion, loose in extension) Capsule Surrounds joint Secondary stabilizer; synovial reflections volar & dorsal Proper collateral Dorsal MC head to palmar P1 Primary stabilizer; tight in flexion, loose in extension base Accessory collateral Palmar MC head to volar plate Palmar to proper collaterals; stabilizes the volar plate Volar (palmar) plate Palmar MC head to palmar P1 Limits extension; volar support base Deep transverse Between adjacent metacarpal Interconnects the volar plates, MCPJs, and metacarpals. (inter)metacarpal bases and MCPJ volar plates Can prevent shortening of isolated metacarpal fractures. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 193

6 Hand • JOINTS Dorsal Flexor digitorum Cleland’s lig. Palmar profundus (FDP) tendon Lateral digital sheet Volar plate of PIPJ Neurovascular bundle Flexor digitorum Digital a. superficialis (FDS) Digital n. tendon Proximal Grayson’s lig. phalanx (P1) Extensor tendon Accessory collateral ligament Proper collateral ligament Accessory collateral ligament Metacarpophalangeal (MP) joint Proper Proximal interphalangeal Volar plates Metacarpal bone collateral (palmar ligament) ligament (PIP) joint Dorsal surface Distal interphalangeal (DIP) joint Palmar Proximal Middle Distal Note: Ligaments of surface metacarpophalangeal and interphalangeal In extension: Phalanges joints are similar medial view Volar plates (palmar ligament) In flexion: medial view LIGAMENT ATTACHMENTS COMMENTS PROXIMAL INTERPHALANGEAL • Hinge joints: Primary motion ϭ flexion & extension (PIPJ: ROM 0-110°, DIPJ: ROM 0-60°). Minimal rotation or devia- tion motion. No “cam effect” in this joint. PIPJ is prone to stiffness/contracture after injury and/or immobilization. Capsule Surrounds joint Weak stabilizer esp. dorsally (central slip adds most support) Proper collateral Center of P1 head to volar P2 Primary stabilizer to deviation. Constant tension through ROM Accessory collateral Volar proximal phalanx head Origin volar to axis of rotation: tight in ext., loose in flexion to volar plate (not bone) This can result in a contracture (do not immobilize in flexion) Volar (palmar) Volar middle phalanx to volar Primary restraint to hyperextension. Firm distal attachment, plate proximal phalanx (via check- looser proximal attachment (more prone to injury). rein ligaments) Checkrein ligaments often contract after injury: contracture OTHER INTERPHALANGEAL • Thumb interphalangeal (IPJ) and finger distal interphalangeal joints (DIPJ) • Hinge joints: Primary motion ϭ flexion & extension (IPJ: ROM 0-90°; DIPJ: ROM 0-60°). Minimal rotation or deviation. Capsule Surrounds joints Weak stabilizer Proper collateral B/w adjacent phalanges Similar to PIPJ, constant tension, no “cam effect” Accessory collateral Volar to collateral ligaments Similar to PIPJ, less prone to contracture than PIPJ Volar (palmar) Volarly b/w phalanges Primary restraint to hyperextension; can be injured plate OTHER STRUCTURES Grayson’s ligament From flexor sheath to skin; volar Stabilizes skin & neurovascular bundle to neurovascular bundle Involved in Dupuytren’s disease/nodules Cleland’s ligament From periosteum to skin Stabilizes skin during flexion/extension; dorsal to NV bundle 194 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

JOINTS • Hand 6 Insertion of small deep slip of extensor tendon Collateral lig. to proximal phalanx and joint capsule Extensor Extensor expansion (hood) tendon Sagittal band Attachment of interosseous m. Volar plate Lumbrical m. Interosseous mm. to base of proximal phalanx (palmar ligament) and joint capsule Flexor digitorum Insertion of lumbrical superficialis tendon (cut) m. to extensor tendon Central band slip Collateral ligs. Note: Black arrows indicate Conjoined lateral band pull of long extensor tendon; Flexor digitorum red arrows indicate pull Finger in flexion: profundus tendon (cut) of interosseous and lateral view lumbrical muscles; dots Volar plate indicate axis of (palmar ligament) rotation of joints. Terminal extensor tendon insertion MOTION STRUCTURE COMMENT Flexion Extension JOINT MOTION Flexion Metacarpophalangeal Joint Extension Flexion Interosseous muscles Insert on proximal phalanx and lateral band (volar to Extension Lumbricals rotation axis) Inserts on radial lateral band (volar to axis of rotation of MCPJ) EDC via sagittal bands Sagittal bands insert on volar plate, creating a “lasso” around proximal phalanx base and extend joint through the lasso. EDC has minimal attachment to P1 (which does not extend the joint) but extends joints via the sagittal bands. Proximal Interphalangeal Joint Flexor digitorum superficialis Primary PIPJ flexor via insertion on middle phalanx volar (FDS) base Flexor digitorum profundus Secondary PIPJ flexor (FDP) EDC via the central slip (band) Central slip of EDC inserts on dorsal P2 base to extend PIPJ Lumbricals via lateral bands Has attachment to radial lateral band (dorsal to rotation axis) Distal Interphalangeal Joint Flexor digitorum profundus Tendon attaches at P3 volar base, pulls through tendon (FDP) sheath EDC via terminal extensor Lateral bands converge at terminal insertion on dorsal tendon P3 base Oblique retinacular ligament Links PIPJ & DIPJ extension; extends DIPJ as PIPJ is (ORL) extended NETTER’S CONCISE ORTHOPAEDIC ANATOMY 195

6 Hand • OTHER STRUCTURES Insertion of central slip of extensor Oblique Lateral Extensor Sagittal Long extensor tendon tendon to base of middle phalanx fibers bands expansion bands Interosseous muscles (hood) Triangular (aponeurosis) ligament Posterior Metacarpal bone (dorsal) view Conjoined Interosseous Part of interosseous lateral bands tendon slip to tendon passes to base Insertion on terminal extensor lateral band of proximal phalanx tendon to base of distal phalanx Lateral slips of and joint capsule long extensor tendon to lateral bands Lumbrical muscle Conjoined Central Oblique Extensor expansion (hood) Insertion of extensor tendon lateral bands slip Lateral fiber to base of middle phalanx Sagittal bands slip Long extensor tendon Insertion of terminal extensor tendon to base of distal phalanx Metacarpal bone Finger in Vincula Interosseous muscles extension: longa Lumbrical muscle lateral view Flexor digitorum profundus tendon Collateral Vinculum Flexor digitorum superficialis tendon ligaments breve Lateral bands STRUCTURE DESCRIPTION COMMENT INTRINSIC APPARATUS • Dorsal Extensor Aponeurosis (also called dorsal expansion, dorsal hood, extensor hood) ‫ ؠ‬Sagittal band Inserts on volar plate (P1); extensor tendon Extends MCPJ via “lasso” around P1 base; (EDC) glides under it radial sagittal bands are weaker, may rupture ‫ ؠ‬Oblique fibers Covers MCPJ and base of proximal phalanx Holds EDC centered over MCPJ ‫ ؠ‬Lateral bands Lateral hood fibers join tendinous portion of Volar to MCPJ axis: flexes MCPJ interossei/lumbricals to form lateral bands Dorsal to PIPJ axis: extends PIPJ • Extrinsic Extensor Tendon (EDC) glides under the dorsal hood (to extend MCP) before trifurcating at prox. phalanx ‫ ؠ‬Lateral slip EDC trifurcates over P1 giving two lateral slips These slips conjoin with lateral bands ‫ ؠ‬Central slip Central slip of trifurcation; inserts base of P2 Extends PIPJ; torn in boutonniere injury ‫ ؠ‬Terminal extensor Confluence of two conjoined lateral bands on Extends DIPJ via insertion on dorsal base of tendon dorsal base of distal phalanx (P3) P3; avulsed in mallet finger injury • Conjoined lateral Confluence of EDC lateral slips and lateral Both join distally to make terminal extensor band bands from extensor aponeurosis tendon • Transverse retinacular From PIPJ volar plate and flexor sheath to Prevents conjoined lateral band dorsal sub- luxation during PIPJ extension ligaments both conjoined lateral bands • Triangular ligament Transverse bands over P2, connects both Prevents lateral band volar subluxation in (aponeurosis) conjoined lateral bands and terminal tendon PIPJ flexion; torn in boutonniere injury • Oblique retinacular From volar P1 to dorsal P3/terminal tendon Extends DIPJ when PIPJ is extended ligament (ORL) OTHER STRUCTURES Junctura tendinae Tendinous connections between ECD ten- Prevents full extension of finger when adja- dons to adjacent fingers proximal to MCPJ cent digit is flexed (see page 155) 196 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OTHER STRUCTURES • Hand 6 Tendinous sheath Tendinous sheath of Common of flexor pollicis flexor pollicis longus flexor sheath longus (radial bursa) (radial bursa) (ulnar bursa) Common flexor sheath (ulnar bursa) Flexor digitorum Flexor digitorum profundus superficialis tendons Thenar space tendons Midpalmar Tendinous space sheath of flexor pollicis longus Lumbrical muscles (radial bursa) (in fascial sheaths) Synovial tendon sheaths of fingers Fascia of adductor pollicis muscle Common flexor sheath Thenar space (ulnar bursa) (opened) (deep to flexor tendon Lumbrical muscles in and 1st lumbrical muscle) fascial sheaths (Synovial) tendinous sheath of finger Midpalmar space Lumbrical muscles in fascial (deep to flexor tendons sheaths (cut and reflected) and lumbrical muscles) Fibrous and synovial (tendon) Midpalmar space sheaths of finger (opened) Palmar aponeurosis Flexor digitorum superficialis Common palmar digital tendon (FDS) artery and nerve Flexor digitorum profundus Lumbrical muscle tendon (FPS) in its fascial sheath Flexor tendons to 5th Profundus and superficialis flexor tendons to 3rd digit digit in common flexor Septum between midpalmar and thenar spaces sheath (ulnar bursa) Thenar space Hypothenar muscles Flexor pollicis longus ten- don in tendon sheath (radial bursa) Extensor pollicis longus tendon Adductor pollicis muscle Palmar interosseous fascia Dorsal interosseous fascia Palmar interosseous muscles Dorsal interosseous muscles Extensor tendons STRUCTURE HAND SPACES COMMENT Thenar space Potential space: site of possible infection Midpalmar space CHARACTERISTICS Potential space: site of possible infection Parona’s space Potential space: “horseshoe” abscess can Between flexor tendons and adductor pollicis Radial bursa occur here as infection tracks proximally Ulnar bursa Between flexor tendons and metacarpals Infection can track proximally Between flexor tendons and pronator quadra- Flexor sheath infection can track proximally tus. Thumb and SF flexor sheaths communi- into bursa cate here Proximal extension of FPL sheath Communicates with SF FDS/FDP flexor tendon sheath NETTER’S CONCISE ORTHOPAEDIC ANATOMY 197

6 Hand • OTHER STRUCTURES Epiphysis Synovial membrane Extensor digitorum tendon Articular cartilage Sagittal section Nail matrix Middle phalanx (germinal matrix) Nail root Eponychium (cuticle) Nail bed Lunula Flexor digitorum superficialis tendo (sterile matrix) Body of nail Distal phalanx Nerves Arteries Septa Fibrous tendon Distal anterior closed space (pulp) sheath finger Cross section through distal Synovial (flexor tendon) sheath phalanx of finger Flexor digitorum profundus tendon Palmar ligament (plate) Articular cavity Subungual space Body of nail Nail bed Minute arteries Distal phalanx Fine nerves Fibrous septa and areolar tissue in anterior to neighboring digit closed space (pulp) Dorsal branches of proper palmar Dorsal digital artery and nerve digital arteries and nerves to dorsum of middle and terminal phalanges Arteries and nerves Nutrient branch to epiphysis Proper palmar digital artery Nutrient branches to metaphysis Proper palmar digital artery and nerve STRUCTURE CHARACTERISTICS COMMENT FINGERTIP Nail Cornified epithelium If completely avulsed, consider replacing to pre- vent eponychium and matrix adhesions Nail bed/matrix Under eponychium and nail to edge of lunula Where nail grows (1mm a week), must be intact Germinal Under nail, distal to lunula (repaired) for normal nail growth Adheres to nail. Repair may prevent nail deformity. Sterile Pulp Multiple septa, nerves, arteries Felon is an infection of the pulp Paronychia Radial and ulnar nail folds Common site of infection Eponychia Proximal nail fold Common site of infection • The digital artery is superficial/volar to the nerve proximally but runs dorsal to the nerve in the finger. • Volar neurovascular bundle supplies the distal finger and fingertip. 198 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MINOR PROCEDURES • Hand 6 Thumb CMC Injection Digital Block Digital block, both 1st metacarpal bone sides of base of finger Trapezium Flexor Sheath Injection Flexor tendon sheath FDS tendon FDP tendon Metacarpal STEPS INJECTION OF THUMB CMC JOINT 1. Ask patient about allergies 2. Palpate thumb CMC joint on volar radial aspect 3. Prepare skin over CMC joint (iodine/antiseptic soap) 4. Anesthetize skin locally (quarter size spot) 5. Palpate base of thumb MC, pull axial distraction on thumb with slight flexion to open joint. Use 22 gauge or smaller needle, and insert into joint (if available use an image intensifier to confirm needle is in joint). Aspirate to ensure nee- dle is not in a vessel. Inject 1-2 ml of 1:1 local (without epinephrine) /corticosteroid preparation into CMC joint. (The fluid should flow easily if needle is in joint) 6. Dress injection site FLEXOR TENDON SHEATH BLOCK 1. Ask patient about allergies 2. Palpate the flexor tendon at the distal palmar crease over metacarpal head/A1 pulley. 3. Prepare skin over palm (iodine/antiseptic soap) 4. Insert 25 gauge needle into flexor tendon at the level of the distal palmar crease. Withdraw needle very slightly so that it is just outside tendon, but inside sheath. Inject 2-3ml of local anesthetic without epinephrine. (Add corticoste- roid if injecting for trigger finger). 5. Dress injection site DIGITAL/METACARPAL BLOCK 1. Prepare skin over dorsal proximal finger web space (iodine/antiseptic soap) 2. Insert 25 gauge needle between metacarpal necks (metacarpal block) or on either side of proximal phalanx (digital block) in digital web space. Aspirate to ensure that needle is not in a vessel. Inject 1-2ml of local anesthetic (without epinephrine) on both sides of the bones. Consider injecting local anesthetic dorsally over the bone as well. 3. Care should be taken not to inject too much fluid into the closed space of the proximal digit. 4. Dress injection site NETTER’S CONCISE ORTHOPAEDIC ANATOMY 199

6 Hand • HISTORY Boxer fracture Fractures and dislocations of thumb Fractures of metacarpal Injury to proximal phalanx or neck commonly result metacarpophalangeal joint of thumb from end-on blow of fist. caused by fall with outstretched Often called street-fighter hand on ski pole or boxer fractures Fight bite Mallet finger Penetration of metacarpophalangeal joint by tooth in fist fight Usually caused by direct blow on extended distal phalanx, as in baseball, volleyball QUESTION ANSWER CLINICAL APPLICATION 1. Hand dominance Right or left 2. Age Young Dominant hand injured more often Middle age-elderly 3. Pain Trauma, infection a. Onset Acute Arthritis, nerve entrapments b. Location Chronic CMC (thumb) Trauma, infection 4. Stiffness Joints (MCPs, IPs) Arthritis Volar (fingers) Arthritis (OA) especially in women 5. Swelling In AM, “catching” Arthritis (osteoarthritis, rheumatoid) Catching/clicking Purulent tenosynovitis (ϩ Kanavel signs) 6. Mass After trauma 7. Trauma No trauma Rheumatoid arthritis Trigger finger 8. Activity Fall, sports injury 9. Neurologic symptoms Open wound Infection (e.g., purulent tenosynovitis, felon, paronychia) Sports, mechanical Trigger finger, arthritides, gout, tendinitis Pain, numbness, tingling Ganglion, Dupuytren’s contracture, giant cell tumor 10. History of arthritides Weakness Multiple joints involved Fracture, dislocation, tendon avulsion, ligament injury Infection Trauma (e.g., fracture, dislocation, tendon or ligament injury) Nerve entrapment (e.g., carpal tunnel), thoracic outlet syndrome, radiculopathy (cervical) Nerve entrapment (usually in wrist or more proximal) Rheumatoid arthritis, Reiter’s syndrome, etc. 200 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Rheumatoid arthritis PHYSICAL EXAM • Hand 6 Boutonniere deformity of index finger with swan-neck deformity Osteoarthritis of other fingers Heberden’s nodes seen in index and middle finger distal interphalangeal joints. Bouchards nodes seen in proximal interphlangeal joints of the ring and small finger. Scaphoid Median nerve compression Ulnar nerve compression Atrophy of thenar muscles Interosseous muscle wasting due to compression of median from ulnar nerve compression nerve Rotation displacement of ring finger. All fingers should point toward scaphoid when clenched EXAMINATION TECHNIQUE CLINICAL APPLICATION Gross deformity Finger position INSPECTION Rheumatoid arthritis Skin, hair, nail changes Fracture Swelling Ulnar drift/swan neck, boutonniere Rotational or angular deformity Dupuytren’s contracture, purulent tenosynovitis Muscle wasting Fracture (acute), fracture malunion Flexion Rotation of digit Neurovascular disorders: Raynaud’s, diabetes, nerve injury Cool, hairless, spoon, etc Osteoarthritis: Heberden’s nodes (at DIPs: #1), DIPs Bouchard’s nodes (at PIPs) PIPs Rheumatoid arthritis MCPs Purulent tenosynovitis Fusiform shape finger Median nerve injury, CTS, C8/T1 pathology Thenar eminence Ulnar nerve injury (e.g., cubital tunnel syndrome) Hypothenar eminence/intrinsics NETTER’S CONCISE ORTHOPAEDIC ANATOMY 201

6 Hand • PHYSICAL EXAM Stenosing tenosynovitis (trigger finger) Infections of the fingers Paronychia Felon Dupuytren’s contracture Patient unable to extend affected finger. It can be extended passively, and extension occurs with distinct and painful snapping action. Circle indicates point of tenderness where nodular enlargement of tendons and sheath is usually palpable Purulent tenosynovitis. Four cardinal signs of Kanavel Flexion contracture of 4th and 5th fingers (most common). 2. Fusiform swelling Dimpling and puckering of skin. Palpable fascial nodules near flexion crease of palm at base of involved fingers 1. Pain on 3. Slight flexion with cordlike formations extending to proximal palm extension 4. Tenderness along tendon sheath EXAMINATION TECHNIQUE CLINICAL APPLICATION Skin PALPATION Metacarpals Phalanges and finger joints Warm, red Infection Soft tissues Cool, dry Neurovascular compromise Each along its length Tenderness may indicate fracture Each separately Tenderness: fracture, arthritis Swelling: arthritis Thenar eminence Wasting indicates median nerve injury Hypothenar eminence Wasting indicates ulnar nerve injury Palm (palmar fascia) Nodules: Dupuytren’s contracture; snapping A1 pulley with finger extension: trigger finger Flexor tendons: along volar finger Tenderness suggests purulent tenosynovitis All aspects of finger tip Tenderness: paronychia or felon 202 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Hand 6 90˚ 75˚ Radial 0˚ Ulnar 20˚ rotation deviation Extension 30˚ 0˚ Flexion 90˚ 75˚ 90˚ 90˚ Range of finger flexion Distal palmar crease Range of thumb opposition MP joint CMC joint MP joint PIP joint DIP joint IP joint Normal finger flexion is Normal thumb composite of flexion of opposition is composite MP, PIP, and DIP joints of movements of CMC, and allows fingertip to MP, and IP joints. touch distal palmar crease. Normal range is to base of little finger. Distal palmar crease EXAMINATION TECHNIQUE CLINICAL APPLICATION MCP joint RANGE OF MOTION PIP joint DIP joint Finger CMC joint Flex 90°, extend 0°, adduct/abduct 0-20° Decreased flexion if casted in extension (collateral MCP joint ligaments shorten) IP joint Flex 110°, extend 0° Hyperextension leads to swan neck Opposition Flex 80°, extend 10° All fingers should point to scaphoid at full flexion Thumb Radial abduction: flex 50°, extend 50° Motion is in plane of palm Palmar abduction: abduct 70, adduct 0° Motion is perpendicular to plane of the palm In plane of palm: flex 50°, extend 0° In plane of palm: flex 75°, extend 10° Motion is mostly at CMC joint Touch thumb to small finger base NETTER’S CONCISE ORTHOPAEDIC ANATOMY 203

6 Hand • PHYSICAL EXAM Sensory testing Median nerve C5-T1 Ulnar nerve C8-T1 Radial nerve C5-C8 Sensory distribution Sensory distribution Sensory distribution Two-point discrimination Finger flexion. Motor testing FDS & FDP. Normal Abnormal Median nerve. C8 Thumb extension. Finger extension. Finger abduction. Anterior interosseous nerve dysfunction (paresis of flexor EPL. Radial nerve EDC. Radial nerve Interosseous m. digitorum profundus and flexor pollicis longus muscles). (PIN). C7 (PIN). C7 Ulnar n. T1 EXAMINATION TECHNIQUE CLINICAL APPLICATION Radial nerve (C6) NEUROVASCULAR Median nerve (C6-7) Ulnar nerve (C8) Sensory Radial nerve/PIN (C7) Dorsal thumb, web space Deficit indicates corresponding nerve/root lesion Median nerve (C8) Radial border, index finger Deficit indicates corresponding nerve/root lesion AIN Motor recurrent branch Ulnar border, small finger Deficit indicates corresponding nerve/root lesion Ulnar nerve (deep branch) (T1) Motor Hoffman’s Finger MCP extension Weakness ϭ Extensor digitorum or nerve lesion Capillary refill Thumb abduction/extension Weakness ϭ APL/EPL or nerve/root lesion Allen’s test Doppler Finger PIP flexion Weakness ϭ FDS or corresponding nerve/root lesion Index finger DIP flexion Weakness ϭ FDP or AIN nerve lesion Thumb IP flexion Weakness ϭ FPL or corresponding nerve/root lesion Thumb opposition Weakness ϭ APB, OP, 1/2 FPB or nerve lesion; (CTS) Finger abduction Weakness ϭ Dorsal/volar interosseous or nerve lesion Thumb adduction Weakness ϭ Adductor pollicis or nerve/root lesion Reflex Flick MF DIPJ into flexion Pathologic if thumb IPJ flexes: myelopathy Vascular Squeeze finger tip Color (blood) should return in less than 2 seconds Occlude both radial & ulnar Hand should “pink up” if artery that was released AND arteries, then release one arches are patent. Failure to “pink up” ϭ arterial injury Arches, digital borders Use if presence of pulses/patent vessels is in question 204 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Positive Froment’s sign PHYSICAL EXAM • Hand 6 When pinching a piece Elson test of paper between thumb Normal intact central slip and index finger, the thumb IP joint will flex PIP joint if the adductor pollicis muscle is weak (ulnar Abnormal ruptured central slip nerve paralysis). Thumb instability test Stress test for ruptur- ed ulnar collateral ligament of thumb (gamekeeper thumb) EXAMINATION TECHNIQUE CLINICAL APPLICATION Profundus test SPECIAL TESTS Sublimus test Stabilize PIPJ in extension, flex DIPJ only Inability to flex DIP alone indicates FDP pathology Froment’s sign Extend all fingers, flex a single finger at PIPJ Inability to flex PIP of isolated finger indicates FDS CMC grind test pathology Finger instabil- ity test Hold paper with thumb and index finger, pull If thumb IP flexion is positive, suggest adductor Thumb paper pollicis weakness and/or ulnar nerve palsy instability test Axial compress and rotate CMC joint Pain indicates arthritis at CMC joint of thumb Bunnell-Littler Stabilize proximal joint, apply varus and valgus Laxity indicates collateral ligament injury test stress Elson test Stabilize MCP, apply valgus stress in extension Laxity at 30°: ulnar collateral ligament injury and 30° of flexion Laxity in extension: accessory collateral ligament and/or volar plate injury Extend MCPJ, passively flex PIPJ Tight or inability to flex PIPJ, improved with MCPJ flexion indicates tight intrinsic muscles Flex PIPJ 90° over table edge, resist P2 exten- DIPJ rigidly extending (via lateral bands) indicates sion central slip injury (boutonnière) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 205

6 Hand • ORIGINS AND INSERTIONS Abductor pollicis brevis Flexor pollicis brevis Muscle attachments Abductor pollicis longus Flexor carpi ulnaris Origins Opponens pollicis Abductor digiti minimi Insertions Flexor carpi radialis Flexor digiti minimi brevis Abductor pollicis Flexor carpi ulnaris brevis Opponens digiti minimi Flexor pollicis brevis Volar interossei Flexor pollicis Abductor digiti minimi longus Flexor digiti minimi brevis Adductor pollicis Extensor carpi Extensor carpi Oblique head ulnaris radialis brevis Transverse head Flexor digitorum superficialis Extensor carpi radialis brevis Flexor digitorum profundus Abductor pollicis Palmar view longus Dorsal interossei Extensor pollicis Abductor digiti brevis minimi Extensor Extensor digitorum pollicis communis (central slip) longus Extensor digitorum communis (terminal tendons) Dorsal view CARPUS METACARPAL PHALANGES—DORSAL PHALANGES—PLANTAR Trapezium Dorsal interosseous Proximal phalanx Proximal phalanx Abductor pollicis brevis Palmar interosseous Ext. pollicis brevis (thumb) Abductor pollicis brevis (thumb) Flexor pollicis brevis Adductor pollicis Dorsal interossei Flexor pollicis brevis (thumb) Opponens pollicis Abd. pollicis longus Abductor digiti minimi Adductor pollicis (thumb) Capitate Opponens pollicis Middle phalanx Palmar interossei Adductor pollicis Opp. digiti minimi Extensor digitorum com- Flexor digiti minimi brevis Hamate Flexor carpi radialis munis (central slip) Abductor digiti minimi Flex. digiti minimi brevis Flexor carpi ulnaris Distal phalanx Opponens digiti minimi Ext. carpi rad. longus Ext. pollicis longus Middle phalanx Pisiform Ext. carpi rad. brevis (thumb) Flexor digitorum superficialis Abductor digiti minimi Extensor carpi ulnaris Extensor digitorum com- munis (terminal tendon) Distal phalanx Flexor pollicis longus (thumb) Flexor digitorum profundus Lumbricals originate on flexor digitorum profundus [FDP] tendon and insert on the radial lateral bands 206 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Hand 6 Anterior (palmar) view Radial artery and palmar carpal branch Pronator quadratus muscle Radius Ulnar nerve Ulnar artery and palmar carpal branch Superficial palmar branch of radial artery Flexor carpi ulnaris tendon Transverse carpal ligament Palmar carpal arterial arch (flexor retinaculum) (reflected) Pisiform Median nerve Opponens pollicis muscle Abductor digiti minimi muscle (cut) Branches of median nerve Deep palmar branch of ulnar artery to thenar muscles and to 1st and deep branch of ulnar nerve and 2nd lumbrical muscles Flexor digiti minimi brevis muscle (cut) Abductor pollicis Opponens digiti minimi muscle brevis muscle (cut) Deep palmar (arterial) arch Palmar metacarpal arteries Flexor pollicis Common palmar digital arteries brevis muscle Deep transverse metacarpal ligaments Adductor pollicis muscle 1st dorsal interosseous muscle Branches from deep Lumbrical muscles (reflected) branch of ulnar nerve to 3rd and 4th lumbrical muscles and to all interosseous muscles MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT THENAR COMPARTMENT Abductor pollicis Scaphoid, Lateral prox. Median Palmar pronation Primary muscle in brevis (APB) trapezium phalanx (thumb) opposition Flexor pollicis brevis 1. Superficial head Trans. carpal lig. Base of thumb Median Thumb MPC Muscle has dual Proximal phalanx Ulnar flexion innervations 2. Deep head Trapezium Opponens pollicis Trapezium Lateral thumb Median Oppose (flex/ Pronates/stabilizes MC abduct) thumb thumb MC ADDUCTOR COMPARTMENT Adductor pollicis 1. Capitate, 2nd Ulnar base of Ulnar Thumb adduc- Test function with tion and thumb Froment’s test 1. Oblique head and 3rd MC proximal pha- MCP flexion 2. Transverse head 2. 3rd metacarpal lanx of thumb HYPOTHENAR COMPARTMENT Palmaris brevis [PB] Transverse carpal Skin on medial Ulnar Wrinkles skin Protects ulnar nerve ligament [TCL] palm Abductor digiti Pisiform (FCU Ulnar base of Ulnar SF abduction Ulnar nerve and minimi [ADQ] tendon) prox. phalanx artery under it Flexor digiti minimi Hamate, TCL Base of proximal Ulnar SF MCP flexion Deep to ADQ and brevis [FDMB] phalanx of SF nerve Opponens digiti min- Hamate, TCL Ulnar side 5th Ulnar Oppose (flex and Deep to other imi [ODQ] metacarpal supinate) SF muscles • Abductor muscles are superficial; opponens muscles are deep • Motor recurrent branch of median innervates thenar muscle and radial 2 lumbricals • Deep branch at ulnar nerve innervates hypothenar, adductor pollicis, interossei, and ulnar 2 lumbricals NETTER’S CONCISE ORTHOPAEDIC ANATOMY 207

6 Hand • MUSCLES Lumbrical muscles Flexor digitorum profundus tendons 1st and 2nd lumbrical muscles 3rd and 4th lumbrical muscles (unipennate) (bipennate) Camper chiasm Flexor digitorum superficialis tendons (cut) Interosseous muscles Ulna Posterior Radius Anterior (dorsal) view (palmar) Radius Palmar interosseous view Ulna muscles (unipennate) 23 Abductor digiti Radial artery Deep transverse 1 minimi muscle metacarpal Abductor pollicis ligaments brevis muscle 43 2 Dorsal interosseous 1 muscles (bipennate) Tendinous slips to extensor expansions (hoods) MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT INTRINSICS Extend PIP, flex Only muscles in body MCP to insert on their own Lumbricals 1 & 2 FDP tendons Radial lateral Median Extend PIP, flex antagonist (FDP). Pal- (radial 2) bands MCP mar to deep trans- Lumbricals 3 & 4 verse MC ligaments. FDP tendons Radial lateral Ulnar Interosseous: (medial 3) bands DAB: Dorsal ABduct dorsal (DIO) Bipennate: each belly Adjacent Proximal phalanx Ulnar Digit abduction has separate insertion metacarpals and extensor Ulnar MCP flexion expansion (lat- PAD: Palmar ADduct Interosseous: Adjacent eral bands) Digit adduction Unipennate palmar (PIO) metacarpals Extensor expan- sion (lateral bands) 208 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Hand 6 Carpal tunnel release Thenar compartment Dorsal interosseous Dorsal incision 2 compartments Adductor Hypothenar compartment compartment Dorsal incision 1 Palmar interosseous Carpal tunnel compartments release Transverse carpal ligament CONTENTS COMPARTMENT COMPARTMENTS (10) Thenar Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis Hypothenar Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi Adductor Adductor pollicis Palmar interosseous (3) Palmar interosseous muscles Dorsal interosseous (4) Dorsal interosseous muscles Incisions FASCIOTOMIES Dorsal (1) 3 incisions (2 dorsal and 1 carpal tunnel release) can release all compartments. Dorsal (2) Over 2nd metacarpal, dissect on both sides: release radial 2 interosseous (2 dorsal, 1 palmar) Medial Over 4th metacarpal, dissect on both sides: release ulnar 4 interosseous (2 dorsal, 2 palmar) Release transverse carpal ligament, then thenar, hypothenar, & adductor compartments NETTER’S CONCISE ORTHOPAEDIC ANATOMY 209

6 Hand • NERVES Cutaneous innervation of the hand Anterior (palmar) view Medial cutaneous nerve of forearm Musculo- Lateral Flexor pollicis brevis muscle cutaneous cutaneous Palmar (deep head only; superficial Palmar nerve nerve of cutaneous head and other thenar mus- cutaneous forearm branch cles supplied by median nerve) branch Superficial branch Radial Superficial Palmar Ulnar nerve branch digital nerve Deep branch branches Median Palmar Palmaris brevis Hypothenar nerve branch muscles Abductor Palmar digiti minimi digital branches Flexor digiti minimi brevis Adductor Opponens pollicis digiti minimi muscle Common palmar digital nerve Communicating branch of median nerve with ulnar nerve Proper palmar digital nerves (dorsal digital nerves are from dorsal branch) Palmar and dorsal Dorsal branches to dorsum of interosseous muscles middle and distal phalanges 3rd and 4th lumbrical muscles (turned down) BRACHIAL PLEXUS Medial Cord Ulnar (C[7]8-T1): Runs in forearm under FCU, on FDP. Dorsal cutaneous branch divides 5cm proximal to wrist. This nerve continues into the dorsal aspect of the ulnar digits as dorsal digital nerves. Ulnar nerve enters Guyon’s canal, then divides into superficial (sensory) and deep (motor) branches. The deep branch bends around the hook of the ha- mate and runs with the deep arterial arch. The superficial branch continues into the palmar aspect of the fingers as the palmar digital nerves. Sensory: Dorsal ulnar hand: via dorsal cutaneous branch Dorsal small & ring fingers: via dorsal digital branches Ulnar proximal palm: via palmar cutaneous branch Ulnar distal palm: via common palmar digital branches Palmar small & ring fingers: via proper palmar digital branches Motor: Superficial (sensory) branch ‫ ؠ‬Palmaris brevis—only muscle innervated by this branch Deep (motor) branch: travels with deep arterial arch • Hypothenar compartment ‫ ؠ‬Abductor digiti minimi (ADM) ‫ ؠ‬Flexor digiti minimi brevis (FDMB) ‫ ؠ‬Opponens digiti minimi (ODM) • Adductor compartment ‫ ؠ‬Adductor pollicis • Intrinsic muscles ‫ ؠ‬Lumbricals (ulnar two [3,4]) ‫ ؠ‬Dorsal interossei (DIO) ‫ ؠ‬Palmar (volar) interossei (VIO) • Thenar compartment ‫ ؠ‬Flexor pollicis brevis (FPB)—deep head only 210 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Hand 6 Posterior (dorsal) view Lateral cutaneous Musculo- Wrist and Hand: Superficial nerve of forearm cutaneous Radial Dissection Medial cutaneous nerve nerve of forearm Lateral (radial) view Posterior cutaneous Radial Division between ulnar nerve of forearm nerve Superficial branch and radial nerve innerva- of radial nerve tion on dorsum of hand is Superficial branch variable; it often aligns with and dorsal digital Medial branch middle or 3rd digit instead branches Lateral branch of 4th digit as shown Dorsal digital Ulnar Dorsal cutaneous Proper palmar Median branches of nerve branch and dorsal digital branches nerve radial nerve digital branches Proper palmar Scaphoid digital branches Thenar Abductor pollicis brevis Palmar Dorsal muscles cutaneous carpal Opponens pollicis branch branch of radial Superficial head Communicating artery of flexor pollicis branch of median brevis (deep nerve with head supplied ulnar nerve by ulnar nerve) Common 1st and 2nd palmar lumbrical digital muscles nerves Dorsal branches to Proper dorsum of middle palmar and distal phalanges digital nerves BRACHIAL PLEXUS Medial and Lateral Cords Median (C[5]8-T1): Runs in forearm on FDP. Palmar cutaneous branch branches proximal to the carpal tunnel. The median nerve enters the carpal tunnel. The motor recurrent branch exits distal to transverse carpal ligament (TCL) and supplies the thenar muscles. Anatomic variants include exit through (at risk in carpal tunnel release) or under the TCL. The remainder of the nerve is sensory and supplies the palmar radial 31⁄2 digits. Sensory: Palm of hand: via palmar cutaneous branch Volar thumb, IF, MF, radial RF: via palmar digital branches Dorsal distal thumb, IF, MF, radial RF: via proper palmar digital branch Motor: Motor (recurrent) branch • Thenar compartment ‫ ؠ‬Abductor pollicis brevis (APB) ‫ ؠ‬Opponens pollicis ‫ ؠ‬Flexor pollicis brevis (FPB)—superficial head only • Intrinsic muscles ‫ ؠ‬Lumbricals (radial two [1,2]) Posterior Cord Radial (C5-T1): Superficial branch runs under brachioradialis to wrist, then bifurcates in medial & lateral branches that supply the dorsal hand & thumb web space. They continue as dorsal digital branches to the dorsal fingers. Sensory: Dorsal radial hand: via superficial branch Dorsal proximal thumb, IF, MF, radial RF: via dorsal digital branches Motor: None (in hand) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 211

6 Hand • ARTERIES Radial artery Ulnar artery and nerve Superficial palmar Transverse carpal ligament branch of radial artery (flexor retinaculum) Recurrent (motor) Deep palmar branch of ulnar artery branch of median and deep branch of ulnar nerve nerve to thenar muscles Superficial branch of ulnar nerve Adductor pollicis muscle Common flexor sheath (ulnar bursa) Proper digital Superficial palmar (arterial) arch nerves and arteries to Common palmar digital nerves thumb and arteries Branches of median Communicating branch of nerve to 1st and 2nd median nerve with ulnar nerve lumbrical muscles Proper palmar digital nerves and arteries Branches of proper palmar digital nerves and arteries to dorsum of middle and distal phalanges Radial artery Ulnar artery and nerve Superficial palmar branch of radial artery Palmar carpal branches of radial and ulnar arteries Deep palmar (arterial) arch Deep palmar branch of Princeps pollicis artery ulnar artery and deep branch of ulnar nerve Proper digital arteries and nerves of thumb Branches to Distal limit of superficial hypothenar muscles palmar arch (Kaplan’s line) Superficial branch Radialis indicis artery of ulnar nerve Palmar metacarpal arteries Deep palmar branch of Common palmar digital arteries ulnar nerve to 3rd and 4th lumbrical, all inter- Proper palmar digital arteries osseous, adductor pollicis, Proper palmar digital nerves from and deep head of flexor median nerve pollicis brevis muscles Proper palmar digital nerves from ulnar nerve COURSE BRANCHES COMMENT/SUPPLY • Radial artery: divides at wrist into superficial branch, which anastomoses with the superficial palmar arch. The deep branch runs thru the bellies of the 1st dorsal interosseous muscle & terminates as the deep palmar arch. • Ulnar artery: divides at wrist into a deep branch, which anastomoses with the deep palmar arch. The superficial branch terminates as the superficial palmar arch. DEEP PALMAR ARCH Runs volar to the bases Princeps pollicis Continuation of deep branch of radial artery of the metacarpals. It is Radialis indicis Supplies radial IF; may branch from deep arch proximal to the superfi- Proper digital arteries of thumb (2) Two terminal branches of bifurcated princeps pollicis cial arch. Anastomoses with common digital arteries Palmar metacarpal (3) SUPERFICIAL PALMAR ARCH Located at Kaplan’s line; Proper palmar digital artery to SF First branch off arch; supplies ulnar small finger distal to the deep arch Common palmar digital (3) In 2nd-4th web spaces, each bifurcates Runs on radial & ulnar borders of digits Proper palmar digital • Superficial arch supplies most of the hand/fingers. It is dominant 2⁄3 of the time. This arch is complete 80% of the time. • Deep arch supplies the thumb (& radial IF). It is usually the nondominant arch. This arch is complete 98% of the time. • The arches are codominant 1⁄3 of the time. Allen’s test determines if arch is complete (but not which is dominant). • Arteries are volar to the nerves in the palm, but cross to become dorsal to the nerves in the fingers. 212 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Osteoarthritis DISORDERS • Hand 6 Rheumatoid arthritis Section through distal interphal- Radiograph of distal interphalangeal Radiograph shows cartilage thinning at proximal angeal joint shows irregular, hyper- joint reveals late-stage degenerative interphalangeal joints, erosion of carpus and plastic bony nodules (Heberden’s changes. Cartilage destruction and wrist joint, osteoporosis, and finger deformities nodes) at articular margins of distal marginal osteophytes (Heberden’s phalanx. Cartilage eroded and joint nodes) space narrowed Late-stage degenerative changes in Boutonniere deformity of index finger with carpometacarpal articulation of thumb swan-neck deformity of other fingers DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT OSTEOARTHRITIS • Loss of articular cartilage Hx: Elderly or hx of injury XR: OA findings: 1. NSAIDs • Due to wear or posttraumatic Pain: worse w/activity joint space loss, 2. Steroid injection • DIPJ #1 (Heberden’s nodes) PE: Nodule/deformity, tender- osteophytes, scle- 3. Arthrodesis/fusion • PIPJ #2 (Bouchard’s nodes) ness, decreased ROM rosis, subchondral 4. Arthroplasty cysts MUCOUS CYST • Ganglion cyst from arthritic Hx: Mass near a joint XR: Joint arthritis 1. Excision of cyst and joint (DIPJ #1) PE: Mass, ϩ/Ϫ tenderness associated osteophyte RHEUMATOID ARTHRITIS • Autoimmune disease attacks HX: Pain and stiffness (worse XR: Joint destruc- 1. Medical management synovium and destroys joints in AM) tion 2. Synovectomy (1 joint) PE: Deformities (ulnar drift, LABS: RF, ANA, ESR, 3. Tendon transfer/repair • MCPJ #1 swan neck, boutonniere) CBC, uric acid 4. Arthrodesis/arthroplasty • Multiple deformities develop SWAN NECK DEFORMITY • FDS insertion/volar plate injury Hx: Injury or RA XR: Shows bony 1. Early: splint • Traumatic or assoc. with RA PE: Deformity: flexed DIPJ, deformity 2. Late: surgical release • Lateral bands subluxate dor- injury hyperextended PIPJ and reconstruction sally, hyperextends PIPJ 3. Arthrodesis BOUTONNIERE DEFORMITY • Central slip (EDC) and triangu- Hx: Traumatic injury or RA XR: Shows bony 1. Early: splint PIPJ in lar ligament injury PE: Deformity: flexed PIPJ, ϩ deformity extension Elson’s test (inability to ex- • Traumatic or assoc. with RA tend the flexed PIPJ) 2. Reconstruct lateral • Lateral bands subluxate volarly, bands and central slip hyperflexes PIPJ 3. Arthrodesis/arthroplasty NETTER’S CONCISE ORTHOPAEDIC ANATOMY 213

6 Hand • DISORDERS Tenosynovitis Paronychia infection A A A A B Eponychium elevated BB from nail surface C Sporotrichosis Horseshoe abscess Tenosynovitis of the middle finger. Treated with zigzag volar incision. Tendon sheath opened by reflecting cruciate pulleys. Fine plastic catheter inserted for irrigation. Lines of incision indicated for tendon sheaths of other fingers (A); radial and ulnar bursae (B); and Parona’s subtendinous space (C) Felon Cross section shows division Begins as small nodule and From focus in thumb spreads of septum in finger pulp spreads to hand, wrist, fore- through radial and ulnar bursae arm (even systemically). and tendon sheath of little finger, with rupture into Parona’s sub- tendinous space DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Tendon sheath infection PURULENT FLEXOR TENOSYNOVITIS 1. Diagnosis Ͻ24hr: IV anti- • Usu. from puncture/bite biotics, close observation • May spread proximally Hx: Pain and swelling XR: Plain films. r/o (I&D if no improvement) PE: Kanaval signs (4): foreign body, air into deep spaces or 1. Flexed position LABS: CBC, ESR, CRP 2. Diagnosis Ͼ24hr: irriga- Parona’s space (horse- 2. Fusiform swelling tion and debridement of shoe abscess) 3. Pain w/passive extension sheath ϩ IV antibiotics 4. Flexor sheath tenderness • Deep infection/abscess 1. Incise and drain (must re- in pulp of finger FELON lease septum in pulp) • Staph. aureus #1 Hx: Pain & swelling XR: Usually not needed 2. Antibiotics (IV vs oral) PE: Pointing abscess, edema, • Infection of nail fold erythema, ϩ/Ϫ drainage 1. Early: warm soaks • #1 hand infection 2. I&D and oral antibiotics • Etiology: nail biting, hang PARONYCHIA / EPONYCHIA 3. Partial nail excision nails Hx: Pain & swelling XR: Usually not needed 1. Incise & drain, IV abx PE: Erythema, tenderness, 2. Wound care/dressing • Infection in deep spaces ϩ/Ϫ drainage or tissues (e.g., thenar, changes as needed hypothenar, Parona’s DEEP SPACE INFECTIONS [horseshoe]) Potassium iodine solution Hx: Pain & swelling XR: Usually normal • Fungal (Sporothrix s.) in- PE: Edema, erythema, tender- MR/CT: May help if fection from plants/roses ness, fluctuance, ϩ/Ϫ drain- diagnosis is unclear age • Spreads via lymphatics SPOROTRICHOSIS Hx: Rash/discoloration XR: Usually not needed PE: Early: single nodule Late: multiple nodules/rash 214 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

DISORDERS • Hand 6 Deep space infections Infection of midpalmar space secondary to tenosynovitis of middle finger. Focus is infected puncture wound at distal crease. Line of incision indicated Infection of thenar space from tenosynovitis of index finger due to puncture wound. Dupuytren’s Stenosing Tenosynovitis (Trigger Finger) Disease Partial excision Inflammatory thickening of fibrous sheath (pulley) of of palmar fascia flexor tendons with fusiform nodular enlargement of with care to avoid both tendons. Broken line indicates line for incision neurovascular bundles. of lateral aspect of pulley DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Usually dominant hand BITES: HUMAN/ANIMAL 1. Td & rabies prophylaxis • “Fight bite”ϭ fist to mouth #1 if indicated • Bacteria: Strep., Staph. a. Hx: Bite, pain & swelling XR: Hand series: rule PE: Puncture wound or out foreign body 2. I&D, wound care Human: Eikenella corr. laceration, edema, ϩ/Ϫ (e.g., tooth) or air 3. IV antibiotics (ampicillin/ Animal: Pasteurella mult. drainage, erythema (local in tissues/joint or tracking proximally) LABS: CBC, ESR, CRP sulbactam) • Tight/thickened A1 pulley en- traps flexor tendon STENOSING TENOSYNOVITIS (TRIGGER FINGER) 1. Splint, occupational rx 2. Corticosteroid injection • Associated with DM, RA, age Hx: 40ϩ, pain, snapping XR: Usually normal • Congenital form in pediatrics or locking (esp. in AM) MR: Not needed, PE into tendon sheath PE: Tender flexor sheath, is diagnostic 3. A1 pulley release • Contracture of palmar fascia snapping with flex./ext. • Myofibroblasts create thick 1. Early (mass, no contrac- DUPUYTREN’S DISEASE ture): reassurance cords of type III collagen • Associated with northern Euro- Hx: Usually male, 40ϩ, XR: Usually normal 2. Late (contracture): surgi- c/o hand mass MR: Not needed if di- cal excision of cords peans (AD), DM, EtOH PE: Nodule in palm, ϩ/Ϫ agnosis is clear. May contracture of MCPJ or be useful if etiology 1. Aspiration/puncture • Ganglion-type cyst of the PIPJ of mass is unclear. 2. Surgical excision if flexor tendon sheath RETINACULAR CYST recurrent • Most common hand mass Hx: Small volar mass XR: Usually normal PE: Firm, “pea”-size nod- MR: Not needed ule, does not move w/tendon NETTER’S CONCISE ORTHOPAEDIC ANATOMY 215

6 Hand • PEDIATRIC DISORDERS Syndactyly Incision lines (preferred method) Dorsal aspect Palmar aspect H G D C F B AE DH G C F B Full-thickness A graft E Suture lines DESCRIPTION EVALUATION TREATMENT • Failure of differentiation of finger tissue SYNDACTYLY 1. Should wait approximately 1yr, then • Most common congenital hand surgically separate fingers Hx: Fingers are connected anomaly PE: Fingers are connected either 2. Careful incision planning and skin • Complete (to finger tip) vs incomplete to tip or incompletely down the grafts improve results • Simple (soft tissue) vs complex (bone) finger XR: Will determine if bones are 1. Nonoperative: stretching, splint • Congenital finger flexion anomaly fused (complex) 2. Functionally debilitating contrac- • Usually PIPJ of small finger • Type 1 (infants), type 2 (adolescents) CAMPTODACTYLY ture: surgical release/tendon • Etiology: abnormal lumbrical or FDS transfer Hx: Finger flexed. Noticed at birth insertion or during adolescent growth 1. Mild: no treatment PE: Inability to fully extend joint 2. Functional deficit: surgical • Deviation of finger in coronal plane XR: Shows flexion, bones typi- • Radial deviation of small finger #1 cally normal correction/realignment osteotomy • Etio: delta-shaped middle phalanx CLINODACTYLY Hx/PE: Deviation of finger, cos- metic and functional complaints XR: Shows delta-shaped middle phalanx 216 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PEDIATRIC DISORDERS • Hand 6 Polydactyly Postaxial Preaxial Congenital constriction band syndrome DESCRIPTION EVALUATION TREATMENT DUPLICATE THUMB (PREAXIAL POLYDACTYLY) 1. Surgical reconstruction to obtain stable thumb. Gener- • An extra thumb or portion thereof Hx/PE: Extra thumb or portion of thumb ally, retain ulnar thumb/ • Wassel classification (7 types): XR: Will show bifid or extra phalanges de- structures & reconstruct pending on which type of duplication radial side (e.g., type 4) Type 4 is most common • Autosomal dominant or sporadic 1. Type I: Small thumb: no • Associated with some syndromes treatment THUMB HYPOPLASIA 2. Types II-IIIA: Reconstruction 3. Types IIIB-V (no CMCJ): am- • Partial or complete absence of Hx/PE: Small to completely absent thumb thumb XR: Range of small, shortened, or absent putation & pollicization bones (phalanges, metacarpal, trapezium). • Blauth classification: Types I– V 1. Complete amputations if • Treatment based on presence of Evaluate for presence of the CMC joint needed CMC joint 2. Release/excise bands, • Associated with some syndromes Z-plasty as needed for skin coverage CONSTRICTION BAND SYNDROME • Constrictive bands lead to digit Hx/PE: Short/truncated fingers with bands at necrosis or diminished growth/ level of diminished growth development. XR: Small, shortened, or absent phalanges • Nonhereditary NETTER’S CONCISE ORTHOPAEDIC ANATOMY 217

6 Hand • SURGICAL APPROACHES Incision Volar approach to finger site Incision may be extended A1 C1 A2 C2 Digital nerve Flexor Digital artery tendons Flexor A3 Grayson’s sheath C3 ligament A4 Cleland’s ligament Digital Midlateral approach to finger nerve Incision Digital site artery Flexor sheath Joint ligaments Flexor digitorum superficialis Flexor digitorum profundus Flexor tendons Digital nerve Digital artery USES INTERNERVOUS DANGERS COMMENT PLANE • Flexor tendons (repair/explore) • Digital nerves FINGER: VOLAR APPROACH • Soft tissue releases • Infection drainage No planes • Digital artery • Make a “zigzag” incision connecting • Digital nerve finger creases • Phalangeal fractures • Flexor tendon • Neurovascular bundle is lateral to the tendon sheath. FINGER: MID-LATERAL APPROACH No planes • Digital nerve • Soft tissues are thin; capsule can be • Digital artery incised if care is not taken. 218 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Topographic Anatomy CHAPTER 7 Osteology Radiology Pelvis Trauma Joints 220 History 221 Physical Exam 225 Origins and Insertions 227 Muscles 232 Nerves 234 Arteries 235 Disorders 237 Surgical Approaches 238 241 244 246 247

7 Pelvis • TOPOGRAPHIC ANATOMY External oblique muscle Linea alba Rectus abdominis muscle Semilunar line Iliac crest Anterior superior Umbilicus iliac spine (ASIS) Inguinal ligament Superficial circumflex iliac vein Hip joint Pubic tubercle Superficial epigastric veins Greater trochanter of femur Pubic symphysis Iliac crest Gluteus medius muscle Erector spinae muscle Sacrum Posterior superior iliac spine Gluteus maximus muscle Greater trochanter of femur Sacroiliac joint Gluteal fold Intergluteal (natal) cleft Ischial tuberosity STRUCTURE CLINICAL APPLICATION Iliac crest Site for contusion of lilac crest (“hip pointers”) Anterior superior iliac spine Common site for autologous bone graft harvest Symphysis pubis Origin of sartorius muscle. An avulsion fracture can occur here. Inguinal ligament Lateral femoral cutaneous nerve (LFCN) courses here and can be entrapped. Landmark used for measuring the “Q” angle of the knee Greater trochanter Erector spinae muscles Site of osteitis pubis; uncommon cause of anterior pelvic pain Posterior superior iliac spine Sacroiliac joint External iliac artery becomes femoral artery here; femoral pulse can be palpated just Ischial tuberosity inferior to the ligament in the femoral triangle. Tenderness can indicate trochanteric bursitis. Overuse and spasm are common causes of lower back pain (LBP). Site of bone graft harvest in posterior spinal procedures. Degeneration of joint can cause lower back pain (LBP). Avulsion fracture (hamstring muscles) or bursitis can occur here. 220 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Pelvis 7 Base of sacrum Superior articular Sacral canal process Ala (lateral Lumbosacral part) articular surface Superior articular process Dorsal surface Ala (wing) Pelvic surface Promontory Promontory Sacral part of pelvic brim (linea terminalis) Sacral hiatus Transverse Anterior (pelvic) Median sagittal section ridges sacral foramina Apex of sacrum Facets of superior articular processes Anterior Transverse process of coccyx inferior Coccyx Auricular surface view Pelvic surface Sacral tuberosity Median sacral crest Posterior Lateral sacral crest Posterior sacral foramen Median sacral crest sacral Sacral canal foramina Intervertebral Intermediate sacral crest foramen Sacral cornu Sacral hiatus (horn) Anterior (pelvic) Coccygeal cornu sacral foramen (horn) Coronal section Dorsal surface Transverse process through S1 foramina of coccyx Posterior superior view CHARACTERISTICS OSSIFY FUSE COMMENTS PELVIS • Combination of 3 bones (two innominate bones & sacrum) and 3 joints (two sacroiliac joints & symphysis pubis) • The pelvis has no inherent stability. It requires ligamentous support for its stability. • Two portions of pelvis divided by pelvic brim/iliopectineal line ‫ ؠ‬False (greater) pelvis—above the brim, bordered by the sacral ala and iliac wings ‫ ؠ‬True (lesser) pelvis—below the brim, bordered by the ischium and pubis SACRUM • 5 vertebra are fused Primary 8wk (fetal) 2-8yr • Transmits weight from spine to pelvis • 4 pairs of foramina Body • Nerves exit through the sacral foramina 2-8yr (left and right) Arches 2-8yr (anterior & posterior) • Ala (wing) expands laterally Costal elements • Ala is common site for sacral fractures • Sacral canal opens to hiatus 20yr • Sacral canal narrows distally before Secondary 11-14yr distally opening to sacral hiatus • Kyphotic (approx. 25°), • Segments fuse to each other at puberty the apex is at S3 COCCYX • 4 vertebrae are fused Primary arch 7-8wk 1-2yr • Is attached to gluteus maximus and • Lack features of typical (fetal) 7-10yr coccygeal m. vertebrae Body • Common site for “tailbone” fracture NETTER’S CONCISE ORTHOPAEDIC ANATOMY 221

7 Pelvis • OSTEOLOGY Lateral view Intermediate zone Tuberculum Anterior Iliac crest Outer lip Gluteal Inferior Ilium lines Wing (ala) of ilium (gluteal surface) Ischium Posterior Pubis Anterior superior iliac spine Posterior superior Anterior inferior iliac spine iliac spine Posterior inferior Acetabulum iliac spine Lunate surface Margin (limbus) of acetabulum Greater sciatic notch Acetabular notch/condyloid fossa Body of ilium Superior pubic ramus Ischial spine Pubic tubercle Lesser sciatic notch Obturator crest Intermediate zone Iliac crest Body of ischium Ischial tuberosity Inferior pubic Inner lip ramus Obturator foramen Coxal Ilium Ramus of ischium Iliac tuberosity bone (8th week) Ischium Anterior superior Posterior (16th week) iliac spine superior Pubis iliac spine (16th week) Wing (ala) of ilium (iliac fossa) Auricular surface Anterior inferior iliac spine (for sacrum) Posterior Arcuate line inferior Iliopubic eminence iliac spine Superior pubic ramus Greater sciatic notch Pecten pubis Ischial spine (pectineal line) Pubic tubercle Body of ilium Lesser sciatic notch Symphyseal surface Body of ischium Obturator groove Ischial tuberosity Inferior pubic ramus Ramus of ischium Obturator foramen Triradiate cartilage CHARACTERISTICS OSSIFY FUSE COMMENTS • 3 bones (ilium, ischium, INNOMINATE BONE • Iliac crest is common site for both pubis) fuse to become one tricortical and cancellous bone bone at triradiate cartilage Primary 2-6mo to acetabulum graft harvest in acetabulum (one in each 15yr body) • Contusion to iliac crest known as • Ilium: body, ala (wing) “hip pointer” • Pubis: inferior & superior Secondary 15yr All fuse 20yr Iliac crest • Iliac crest ossification used to de- rami Triradiate termine skeletal maturity (Risser • Ischium: body & tuberosity Ischial tuberosity stage) • Acetabulum: “socket” of hip AIIS Pubis • Multiple iliac spines serve as ana- joint, has 2 walls (anterior & tomic landmarks & muscle inser- posterior) & notch/condyloid tion sites (ASIS, AIIS, PSIS, PIIS) fossa inferiorly. Articular car- tilage is horseshoe shaped • Acetabulum: 45° oblique orienta- tion, 15° anteverted 222 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Pelvis 7 Iliac crest Inner lip Sacral L3 Transverse processes of lumbar vertebrae Intermediate zone promontory L4 Outer lip L5 Iliac tuberosity Tuberculum Iliac crest Anterior superior iliac spine Coccyx Wing (ala) of ilium Anterior inferior iliac spine Pubic arch Sacrum Iliopubic eminence Superior pubic ramus Greater sciatic notch Obturator foramen Pubic tubercle Arcuate line Inferior pubic ramus Ischial spine Inferior pubic ligament Lesser sciatic notch Greater trochanter of femur Pecten pubis (pectineal line) Pubic symphysis Ischial tuberosity Lesser trochanter of femur STRUCTURE ATTACHMENTS/RELATED STRUCTURES COMMENT Anterior superior LANDMARKS AND OTHER STRUCTURES OF THE PELVIS iliac spine (ASIS) Sartorius • LFCN crosses the ASIS & can be compressed there Anterior inferior Inguinal ligament • Sartorius can avulse from it (avulsion fx) iliac spine (AIIS) Transverse & int. oblique abdominal m. • Landmark to measure Q angle of the knee Posterior superior Rectus femoris • Rectus femoris can avulse from it (avulsion fx) iliac spine (PSIS) Tensor fasciae latae Arcuate line Iliofemoral ligament (hip capsule) Gluteal lines Gtr. trochanter Posterior SI ligaments • Excellent bone graft site Lesser trochanter Marked by skin dimple Ischial tuberosity Pectineus • Aka pectineal line. Strong, weight-bearing region Ischial spine 3 lines: anterior, inferior, posterior • Separate origins of gluteal muscles Lesser sciatic foramen SEE ORIGINS/INSERTIONS • Tender with trochanteric bursitis Greater sciatic Iliacus/psoas muscle • Tendon can snap over trochanter (“snapping hip”) foramen SEE ORIGINS/INSERTIONS • Excessive friction ϭ bursitis (weaver’s bottom) Sacrotuberous ligaments • Hamstrings can avulse (avulsion fx) Coccygeus & levator ani attach Sacrospinous ligaments Short external rotators exit: • Obturator internus is landmark to posterior column Obturator externus • Obt. externus not seen in posterior approach Obturator internus Structures that exit: • Piriformis muscle is the reference point 1. Superior gluteal nerve • Superior gluteal nerve and artery exit superior to the 2. Superior gluteal artery 3. Piriformis muscle piriformis 4. Pudendal nerve • POP’S IQ is a mnemonic for the nerves (structures) 5. Inferior pudendal artery 6. Nerve to the Obturator internus that exit inferior to the piriformis (medial to lateral) 7. Posterior Cutaneous nerve of thigh (see page 243) 8. Sciatic nerve • Sciatic nerve (especially peroneal division) may exit 9. Inferior gluteal nerve pelvis above or through the piriformis as an anatomic 10. Inferior gluteal artery variation 11. Nerve to Quadratus femoris NETTER’S CONCISE ORTHOPAEDIC ANATOMY 223

7 Pelvis • OSTEOLOGY Lateral view Iliac wing Medial view Greater sciatic Posterior column notch Anterior column Lesser sciatic notch Acetabulum Greater sciatic notch Ischial Anterior wall Ischial spine tuberosity Superior pubic ramus Lesser sciatic notch Obturator Pecten pubis Ischial tuberosity foramen (pectineal line) Pubic tubercle Inferior Obturator pubic ramus foramen Posterior superior quadrant (“safe zone”) ASIS Anterior superior quadrant Center of acetabulum Posterior inferior quadrant Anterior inferior quadrant STRUCTURE RELATED STRUCTURES COMMENT ACETABULAR COLUMNS Anterior (iliopubic) 1. Superior pubic ramus Involved in several different fracture patterns 2. Anterior acetabular wall 3. Anterior iliac wing 4. Pelvic brim Posterior (ilioischial) 1. Ischial tuberosity Involved in several different fracture patterns 2. Posterior acetabular wall 3. Greater & lesser sciatic notches ACETABULAR ZONES Zones defined by 2 lines: 1. ASIS to center of acetabulum, 2. perpendicular to line 1 Structures can be injured when screws are placed in these zones (e.g., acetabular cups) Anterior superior External iliac artery & vein Do not put screws in this zone Anterior inferior Obturator nerve, artery, vein Do not put screws in this zone Posterior superior Sciatic nerve This is the safe zone Superior gluteal nerve, artery, vein Posterior inferior Sciatic nerve This is a secondary safe zone. Safe screw placement Inferior gluteal nerve, artery, vein can be achieved with care if necessary. Internal pudendal nerve, artery, vein 224 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Sacroiliac joint RADIOLOGY • Pelvis 7 Ilioishial line Radiograph, AP pelvis (posterior column) Sacrum Anterior wall Iliopectineal line (of acetabulum) (anterior column) Teardrop Pubic symphysis Roof (of acetabulum) Posterior wall (of acetabulum) RADIOGRAPH TECHNIQUE FINDINGS CLINICAL APPLICATION AP (anteroposterior) Screening for fractures (sacral, AP, IR feet 15°, beam 6 radiographic lines: directed at midpelvis 1. Iliopectineal (ant. column) pelvic acetabular, proximal fe- 2. Ilioischial (post. column) mur), use ATLS protocol; dys- Pelvic inlet view AP, beam 45° caudal 3. Radiographic “teardrop” plasia, degenerative joint 4. Acetabular roof (“dome”) disease/arthritis 5. Ant. acetabulum rim/wall 6. Post. acetabulum rim/wall Pelvic ring fractures: shows posterior displacement or Sacroiliac joints, pelvic brim/ symphysis widening pubic rami, sacrum Pelvic ring fractures: shows su- perior displacement of hemi- Pelvic outlet view AP, beam 45° cephalad Iliac crest, symphysis pubis, pelvis sacral foramina Acetabulum fx: anterior column, Oblique/Judet views Beam at affected hip: posterior wall Obturator oblique Elevate affected hip 45° Obturator foramen Acetabulum fx: posterior column, anterior wall Iliac oblique Elevate unaffected hip Iliac crest, sciatic notches CT 45° Fractures, especially sacrum OTHER STUDIES & acetabulum Axial, coronal, & sagittal Articular congruity, fx fragments Labral tears, tumors, stress fx Tumors, infection MRI Sequence protocols Soft tissues: muscles, cartilage Bone scan All bones evaluated NETTER’S CONCISE ORTHOPAEDIC ANATOMY 225

7 Pelvis • RADIOLOGY Sacrum Inlet view Outlet view Iliac crest Iliac oblique (Judet) Obturator oblique (Judet) Sacroiliac L5 joint Sacrum Femoral head Sacro- Superior iliac pubic joint ramus Femoral Pubic head symphysis Inferior Inferior pubic pubic ramus ramus Iliac crest Posterior wall (acetabulum) Posterior column Anterior column Anterior wall (acetabulum) Obturator foramen CT pelvis CT pelvis Iliac crest Sacrum Sacroiliac Fovea Posterior wall Femoral head joint (acetabulum) Acetabulum Anterior wall (acetabulum) 226 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7 Vertical sacral fracture, Denis classification Zone Zone Zone 1 2 3 Ala (wing) Promontory Sacral part of pelvic brim (linea terminalis) Anterior Pelvic surface inferior view Sacral fractures Coccyx fracture Transverse fracture of the sacrum that is minimally displaced Fracture usually requires no treatment other than care in sitting; inflatable ring helpful. Pain may persist for a long time. DESCRIPTION EVALUATION CLASSIFICATION TREATMENT SACRAL FRACTURE • Mechanism: elderly—fall; Hx: Trauma (fall or By direction of fracture • Minimally displaced/stable: young—high energy (e.g., accident), pain ϩրϪ • Vertical. Denis: ‫ ؠ‬Nonoperative MVA) neurologic sx PE: Palpate spine & sa- ‫ ؠ‬Zone 1: lateral to • Displaced/unstable: • Isolated injuries rare, usually crum. Complete neuro foramina ‫ ؠ‬Closed reduction and per- assoc. w/pelvis or spine fx exam including rectal cutaneous fixation exam. ‫ ؠ‬Zone 2: through ‫ ؠ‬Open reduction, internal • Nerve root injury very com- XR: AP pelvis, lateral foramina fixation mon sacrum CT: Necessary for ‫ ؠ‬Zone 3: medial to • Nerve injury: decompression • Plain XR identifies Ͻ50% of diagnosis & preop foramina fractures planning • II. Transverse • Easily missed & difficult to • III. Oblique treat, can lead to chronic • Complex: “U” or “H” pain shape COMPLICATIONS: Nerve root injury & cauda equina syndrome, esp. zone 3 fractures; nonunion/malunion, chronic pain NETTER’S CONCISE ORTHOPAEDIC ANATOMY 227

7 Pelvis • TRAUMA Classification of pelvic fractures (Young and Burgess) Anteroposterior Compression Type I Anteroposterior Compression Type II (APC-I) (APC-II) Anteroposterior Compression Type III (APC-III) DESCRIPTION EVALUATION CLASSIFICATION TREATMENT PELVIC RING FRACTURE • Mechanism: high-energy Hx: High-energy Young & Burgess: • ATLS protocol. Treat blunt trauma (e.g., MVA) trauma, pain ϩ/Ϫ AP Compression (APC) life-threatening injuries neurologic sx I. Ͻ2.5cm pubic diastasis • Multiple associated injuries: PE: Inspect perineum • Pelvic hemorrhage: pel- GI, GU, extremity fxs, neuro- for open injury. LE ϩ 1 or 2 pubic rami vis compression (e.g., logic, vascular, head (LC) may be malrotated. fractures sheet) or external fixa- Pelvic “rock.” Rectal II. Ͼ2.5cm diastasis ϩ an- tion to reduce pelvic • Very high morbidity, usually & vaginal exams for terior SI injury, but verti- volume due to uncontrolled hemor- associated injuries. cally stable rhage (venousϾarterial Complete neuro exam III. Complete ant. (symphy- • Diverting colostomy for bleeding) esp. w/ APC3 incl. rectal tone & bul- sis) & post. (SIJ) disrup- open injury or any (“open book”) fxs bocavernosus re- tion. Unstable communication flexes. Lateral Compression (LC) w/open bowel • Open fracture has higher XR: AP pelvis, inlet and I. Sacral compression ϩ morbidity and complication outlet views are es- ipsilateral rami fracture • Nonoperative: WBAT rate. sential. II. LC1 ϩ iliac wing fx or for LC1, APC1, ramus CT: Especially useful to post. SIJ injury. Vertically fx • Stability of fx based on liga- define sacral/SIJ in- stable ment disruption (esp. ST, SS, jury III. LC 2 with contralateral • Operative for LC2 & 3; posterior SI) AGRAM: If hemody- APC3 (“windswept” APC 2 & 3, vertical namically unstable af- pelvis) stress • Avulsion of iliolumbar ter pelvic stabilization; Vertical Shear ‫ ؠ‬Anterior: ORIF of ligament/L5 transverse consider embolization SIJ & ST/SS ligament dis- symphysis process suggests unstable fx of artery ruption ϩ rami fxs. ‫ ؠ‬Post: 1. ORIF of iliac Vertically unstable wing and sacral frac- • Lateral compression most tures; 2. SI screws common for dislocated SIJ ‫ ؠ‬LC1: posterior-directed force ‫ ؠ‬LC2: anterior-directed force COMPLICATIONS: Hemorrhage (venousϾarterial [internal pudendal a. Ͼ superior gluteal a.]), neurologic injuries (L5 root at risk w/SI screws), malunion/nonunion, chronic pain (esp. at SIJ) and functional disability, infection, thromboembolism 228 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7 Classification of Pelvic Fractures (Young and Burgess) Lateral Compression Type I Lateral Compression Type II Lateral Compression Type III (LC-I) (LC-II) (LC-III) Pelvic rami fractures Vertical shear Fracture of pelvis without Fracture of ipsilateral pubic and ischial ramus disruption of pelvic ring requires only symptomatic treatment with short- term bed rest and limited activity with walker- Avulsions or crutch-assisted ambulation for 4 to 6 weeks. Avulsion of anterior superior iliac spine due to pull of sartorius muscle Avulsion of ischial Avulsion of anterior tuberosity due to inferior iliac spine pull of hamstring due to pull of rectus muscles femoris muscle DESCRIPTION EVALUATION CLASSIFICATION TREATMENT PELVIC FRACTURE—OTHER • Isolated fxs: treat with limited rest, WBAT • Mechanism: Low-energy Hx: Pain, esp. with WB Isolated fxs: Inferior or supe- trauma (fall, sports injury, PE: TTP at bony site rior pubic rami, iliac wing/ • Avulsion fx: most treated etc) XR: AP, inlet/outlet crest nonoperatively. Reattach views Avulsions: ASIS (sartorius), if widely displaced. • Stable isolated fractures, CT: Often not needed, AIIS (rectus femoris), ischial pelvic ring not disrupted can determine dis- tuberosity (hamstrings) placement • Can occur in osteopenic bone COMPLICATIONS: Malunion/nonunion, chronic pain/disability, thromboembolism NETTER’S CONCISE ORTHOPAEDIC ANATOMY 229

7 Pelvis • TRAUMA Acetabulum—Elementary Fractures Fracture of posterior wall Fracture of posterior column Wedge fracture of anterior wall Fracture of anterior column Transverse fracture DESCRIPTION EVALUATION CLASSIFICATION TREATMENT ACETABULAR FRACTURE • Mechanism: high- Hx: High-energy trauma, Letournel & Judet: • Reduce hip if dislocated energy blunt trauma pain, inability to WB (e.g., MVA); fem. head PE: LE may be malrotated. • Elementary fractures (traction if necessary to into acetabulum Inspect skin for Morel- ‫ ؠ‬Posterior wall Lavalle lesion. Neuro ‫ ؠ‬Posterior column maintain reduction) • Fracture pattern deter- exam. ‫ ؠ‬Anterior wall mined by force vector XR: AP pelvis, obturator & ‫ ؠ‬Anterior column • Nonoperative: NWB for & position of femoral iliac obliques (Judet ‫ ؠ‬Transverse head at impact views) are essential. Roof 12wk arc angle: center of head • Associated fractures ‫ ؠ‬Ͻ2mm articular dis- • Multiple associated in- to fx (Ͻ45° is WB ) ‫ ؠ‬Post. column & post. juries: GI, GU, extrem- CT: Essential to accurately placement ity fractures define fx (size, impaction, wall ‫ ؠ‬Roof arc angle Ͼ45° articular involvement, LB ) ‫ ؠ‬Transverse & post. wall ‫ ؠ‬Posterior wall fx Ͻ20- • Surgical approaches: & do preop planning ‫ ؠ‬T type ‫ ؠ‬Kocher-Langenbeck: ‫ ؠ‬Ant. column and post. 30% posterior fxs (PW, PC, transverse, T type) hemitransverse • Operative: ORIF, NWB 12wk ‫ ؠ‬Ilioinguinal: anterior ‫ ؠ‬Both columns ‫ ؠ‬2mm articular displace- fxs (AW, AC/HT, both ment columns) ‫ ؠ‬Posterior wall Ͼ40% ‫ ؠ‬Irreducible fx/dx ‫ ؠ‬Marginal impaction ‫ ؠ‬Loose bodies in hip joint • XRT for HO prophylaxis COMPLICATIONS: Posttraumatic arthritis, nerve injury (sciatic nerve), postsurgical (heterotopic ossification [HO], sciatic nerve injury, bleeding), malunion/nonunion, infection (assoc. with Morel-Lavalle lesion), thromboembolism 230 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7 Acetabulum—Associated Fractures Posterior column/posterior wall Transverse/posterior wall T-shaped fracture Anterior column/posterior hemi transverse Both columns Open reduction internal fixation acetabular fracture Posterior column fracture. Anterior column fracture. Transverse fracture. Repair with plate and lag screw Repair with plate and long screws Repair with plate and lag screw NETTER’S CONCISE ORTHOPAEDIC ANATOMY 231

7 Pelvis • JOINTS Iliolumbar ligament Iliac crest Supraspinous ligament Posterior superior iliac spine Posterior sacroiliac ligaments Posterior (dorsal) sacral foramina Greater sciatic foramen Anterior longitudinal Anterior superior iliac spine ligament Sacrospinous ligament Sacrotuberous ligament Lesser sciatic foramen Iliac Iliolumbar Acetabular margin fossa ligament Ischial tuberosity Tendon of long head of biceps femoris muscle Iliac crest Anterior sacroiliac ligament Deep Posterior Sacral promontory sacrococcygeal Superficial ligaments Greater sciatic foramen Anterior superior iliac spine Lateral sacrococcygeal Linea Sacrotuberous ligament ligament terminalis Sacrospinous ligament Posterior view Anterior inferior iliac spine Ischial spine Arcuate line Lesser sciatic foramen Iliopectineal Iliopubic eminence line Superior pubic ramus Pecten pubis (pectineal line) Anterior view Anterior sacral (pelvic) foramina Obturator foramen Pubic Inferior pubic ramus tubercle Coccyx Anterior sacrococcygeal ligaments Pubic symphysis LIGAMENTS ATTACHMENTS COMMENTS SACROILIAC • This is a gliding joint. It has minimal rotational motion during gait. There should be no vertical motion in the normal joint. • Vertical stability is essential; the body weight is transmitted through this joint. • Articular surface (located inferiorly in articulation) covered with: sacrum (articular cartilage), ilium (fibrocartilage) Posterior sacroiliac Posterolateral sacrum to posteromedial ilium Strongest in pelvis: key to vertical stability ‫ ؠ‬Short sacroiliac Oblique orientation: sacrum to PSIS & PIIS Resists rotational forces ‫ ؠ‬Long sacroiliac Vertical orientation: sacrum to PSIS Resists vertical forces. Blends with sacrotuberous ligament Anterior sacroiliac Anterior sacrum to anterior ilium Weaker than posterior; resists rotational forces Interosseous Sacrum to ilium Adds support to anterior & posterior ligaments PELVIC STABILITY Rotational stability Tranverse/horizontal orientation Short posterior SI, anterior SI, sacrospinous, iliolumbar ligaments Vertical stability Longitudinal/vertical orientation Long posterior SI, sacrotuberous, lumbosacral ligaments 232 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

JOINTS • Pelvis 7 Median (sagittal) section Body of L5 vertebra False pelvis Iliac Intermediate zone Lumbosacral (L5—S1) intervertebral disc crest Inner lip Sacral promontory Greater sciatic foramen Iliac fossa (wing True pelvis of ilium) Ischial spine Sacrospinous ligament Anterior superior Lesser sciatic foramen iliac spine Sacrotuberous ligament Coccyx Arcuate line Anterior inferior iliac spine Iliopubic eminence Obturator canal Superior pubic ramus Pecten pubis (pectineal line) Pubic tubercle Ischial tuberosity Symphyseal surface Body of L4 vertebra Obturator membrane Iliac crest Lateral view Wing (ala) of ilium Posterior superior iliac spine (gluteal surface) Median sacral crest Body of ilium Anterior superior Posterior inferior iliac spine iliac spine Anterior inferior Posterior sacroiliac ligament iliac spine Greater sciatic foramen Sacrospinous ligament Acetabulum Posterior and lateral Acetabular labrum sacrococcygeal ligaments Lunate (articular) surface Acetabular notch Sacrotuberous ligament Ischial spine Transverse acetabular ligament Superior pubic ramus Lesser sciatic foramen Pubic tubercle Ischial tuberosity Obturator canal Obturator membrane Inferior pubic ramus LIGAMENTS ATTACHMENTS COMMENTS PUBIC SYMPHYSIS • Anterior articulation of two hemipelves. Articulating surfaces are covered with hyaline cartilage. • Fibrocartilage disc between two pubic bones in the joint Superior pubic Both pubic bones superiorly (& anteriorly) Strongest supporting ligament Arcuate pubic Both pubic bones inferiorly Muscle attachments also support inferiorly OTHER LIGAMENTS Sacrospinous Anterolateral sacrum to spinous process Resists rotation, divides sciatic notches Sacrotuberous Posterolateral sacrum to ischial tuberosity Resists vertical forces, provides vertical stability Iliolumbar L4 & L5 transverse process to posterior Avulsion fracture sign of unstable pelvic ring injury iliac crest Lumbosacral L5 transverse process to sacral ala Anterior support, assists in providing vertical stability NETTER’S CONCISE ORTHOPAEDIC ANATOMY 233

7 Pelvis • HISTORY Anteroposterior compression pelvic fracture of pelvis (open book fracture) Forceful frontal impact causes anteroposterior compression of pelvis Lateral compression injury pelvic (overlapping pelvis) Caused by forceful blow to side of pelvis QUESTION ANSWER CLINICAL APPLICATION 1. Age Young Ankylosing spondylitis 2. Pain Middle aged–elderly Sacroiliitis, decreased mobility a. Onset b. Character Acute Trauma: fracture, dislocation, contusion c. Occurrence Chronic Systemic inflammatory, degenerative disorder Deep, non-specific Sacroiliac etiology, infection, tumor 3. PMHx Radiating To thigh or buttock, SI joint, L-spine 4. Trauma In/out of bed, on stairs Sacroiliac etiology Adducting legs Symphysis pubis etiology 5. Activity/work 6. Neurologic symptoms Pregnancy Laxity of ligament in SI joint causes pain 7. History of arthritides Fall on buttock, twist injury Sacroiliac joint injury High velocity: MVA, fall Fracture, pelvic ring disruption Twisting, stand on one-leg Sacroiliac etiology Pain, numbness, tingling Spine etiology, sacroiliac etiology Multiple joints involved SI involvement of RA, Reiter’s syndrome, ankylosing spondylitis, etc 234 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Pelvis 7 With palpation Ischial bursitis (deep pain and tenderness over ischial tuberosity) Hip pointer With palpation Palpate illiac crest for tenderness Sacroiliitis (deep pain and tenderness over sacroiliac joint) EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION INSPECTION Skin Discoloration, wounds Recent trauma ASIS’s/iliac crests Both level (same plane) If on different plane: leg length discrepancy, sacral torsion Lumbar curvature Increased lordosis Flexion contracture Decreased lordosis Paraspinal muscle spasm PALPATION Bony structures Standing: ASIS, pubic & Unequal side to side ϭ pelvic obliquity: leg length discrepancy iliac tubercles, PSIS Lying: iliac crest, “Hip pointer”/contusion, fractures ischial tuberosity Ischial bursitis (“weaver’s bottom”), avulsion fx Soft tissues Sacroiliac joint Sacroiliitis Inguinal ligament Protruding mass: hernia Femoral pulse & nodes Diminished pulse: vascular injury; palpable nodes: infection Muscle groups Each group should be symmetric bilaterally RANGE OF MOTION Forward flexion Standing: bend forward PSISs should elevate slightly (equally) Extension Standing: lean backward PSISs should depress (equally) Hip flexion Standing: knee to chest PSIS should drop but will elevate in hypomobile SI joint Ischial tuberosity should move laterally; will elevate in hypomobile SI joint NETTER’S CONCISE ORTHOPAEDIC ANATOMY 235

7 Pelvis • PHYSICAL EXAM Rectal examination Trendelenburg test Rectal examination for sphincter function and perianal Left: patient demon- sensation. Gross blood indicates pelvic fracture strates negative communicating with colon. Trendelenburg test of normal right hip. Right: positive test of involved left hip. When weight is on affected side, normal hip drops, indicat- ing weakness of left gluteus medius muscle. Trunk shifts left as patient attempts to maintain balance Vaginal examination Bulbcavernosus reflex test EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION Iliohypogastric nerve (L1) NEUROVASCULAR Ilioinguinal nerve (L1) Genitofemoral nerve Sensory Lateral femoral cutane- ous nerve (L2-3) Suprapubic, lat butt/thigh Deficit indicates corresponding nerve/root lesion Pudendal nerve (S2-4) Inguinal region Deficit indicates corresponding nerve/root lesion Femoral (L2-4) Inferior gluteal nerve Scrotum or mons Deficit indicates corresponding nerve/root lesion N. to quad. femoris Superior gluteal nerve Lateral hip/thigh Deficit indicates corresponding nerve/root lesion (e.g., meralgia paresthetica) Reflex Perineum Deficit indicates corresponding nerve/root lesion Pulses Motor Pelvic rock SI stress test Hip flexion Weakness ϭ iliopsoas or corresponding nerve/root lesion Trendelenburg sign External rotation Weakness ϭ gluteus maximus or nerve/root lesion Patrick (FABER) External rotation Weakness ϭ short rotators or corresponding nerve/root lesion Meralgia Rectal and vaginal Abduction Weakness ϭ glut. med./min or nerve/root lesion Other Bulbocavernosus Finger in rectum, squeeze or pull penis (Foley)/clitoris; anal sphincter should contract Femoral pulse Diminished pulse abnormal SPECIAL TESTS Push both iliac crests Instability/motion indicates pelvic ring injury Press ASIS & iliac crests Pain in SI could be SI ligament injury Standing: lift one leg Flexed side: pelvis should elevate; if pelvis falls, abductor or (flex hip) gluteus medius (superior gluteal n.) dysfunction Flex, Abduct, ER hip, Positive if pain or LE will not continue to abduct below other then abduct more leg; SI joint pathology Pressure medial to ASIS Reproduction to pain, burning, numbness ϭ LFCN entrapment Especially after trauma Gross blood indicates trauma communicating with those organs 236 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

ORIGINS AND INSERTIONS • Pelvis 7 Iliacus muscle Origin of psoas major muscle Origins from sides of vertebral bodies, Insertions Sartorius muscle intervertebral discs and transverse processes (T12-L4) Gluteus Rectus femoris medius muscle Direct head Piriformis muscle Indirect head Gluteus Pectineus muscle minimus muscle Obturator internus and superior and Adductor longus muscle Tensor fasciae inferior gemellus latae muscle muscles Adductor brevis muscle Sartorius muscle Piriformis Gracilis muscle muscle Obturator Rectus femoris Gluteus externus muscle minimus muscle muscle Obturator Adductor externus muscle Vastus lateralis magnus muscle muscle Quadratus Gluteus femoris medius muscle Iliopsoas muscle Quadratus muscle Gluteus femoris muscle Iliopsoas muscle Vastus medialis maximus Gluteus muscle muscle maximus muscle Vastus intermedius Superior gemellus muscle Vastus muscle lateralis muscle Inferior gemellus muscle Adductor magnus muscle Quadratus femoris muscle LINEA ASPERA Obturator internus muscle Vastus lateralis Adductor magnus muscle Vastus intermedius Vastus medialis Biceps femoris (long head) Biceps femoris (SH) and semitendinosus muscles Gluteus maximus Semimembranosus muscle Adductor magnus Adductor brevis PUBIC RAMI GREATER TROCHANTER ISCHIAL TUBEROSITY Adductor longus Pectineus Pectineus ORIGINS Adductor longus Adductor brevis Semimembranosus Adductor magnus* Semitendinosus Gracilis Biceps femoris (LH) Obturator internus Adductor magnus* Obturator externus ISCHIUM Quadratus femoris *Has two origins Inferior gemellus INSERTIONS Gluteus medius (posterior) Gluteus minimus (anterior) Quadratus femoris (inferior) Obturator externus (fossa) SHORT EXTERNAL ROTATORS Piriformis Superior gemellus Obturator internus Inferior gemellus NETTER’S CONCISE ORTHOPAEDIC ANATOMY 237

7 Pelvis • MUSCLES L1 Quadratus lumborum L2 muscle L3 Psoas minor muscle L4 Psoas major muscle L5 Transversus abdominis muscle Anterior Internal oblique muscle inferior External oblique muscle iliac spine Iliacus muscle Pubic tubercle Pubic symphysis Urethra Anterior superior iliac spine Piriformis muscle Rectum Coccygeus (ischiococcygeus) muscle Ischial spine Inguinal ligament (Poupart’s) Obturator internus muscle Rectococcygeus muscle Opening for femoral vessels Levator ani muscle Lesser trochanter of femur Abductors Note: Arrows indicate direction (gluteus medius of action of iliopsoas muscle. and minimus muscles) Adductors MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT HIP FLEXORS Psoas major T12-L5 vertebrae Lesser trochanter Femoral Flex hip Covers lumbar plexus Psoas minor T12-L1 vertebrae Iliopubic eminence L1-ventral Assists in hip Weak—present in ramus flexion 50% of people Iliacus Iliac fossa/sacral ala Lesser trochanter Femoral Flex hip Covers ant. ilium Also see muscles of the thigh/hip in Chapter 8. 238 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Superficial dissection Iliac crest MUSCLES • Pelvis 7 Gluteal aponeurosis over Gluteus medius muscle Deeper dissection Gluteus minimus muscle Gluteus maximus muscle Piriformis muscle Sciatic nerve Sacrospinous ligament Superior gemellus muscle Obturator internus muscle Inferior gemellus muscle Sacrotuberous ligament Quadratus femoris muscle Ischial tuberosity Greater trochanter MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Tensor fas- HIP ABDUCTORS A plane in anterior ciae latae approach to hip Gluteus Iliac crest, ASIS Iliotibial band/ Superior Abducts, flex, Trendelenburg gait if medius proximal tibia gluteal IR thigh muscle is out Gluteus Works in conjunction minimus Ilium b/w ant. and Greater trochan- Superior Abducts, IR with medius post. gluteal lines ter (posterior) gluteal thigh Gluteus Must be split in poste- maximus Ilium b/w ant. and Greater trochan- Superior Abducts, IR rior approach to hip Obturator inf. gluteal lines thigh Inserts at start point for externus ter (anterior) gluteal IM nail Piriformis HIP EXTENSORS AND EXTERNAL ROTATORS Used as landmark for sciatic nerve Superior Ilium, dorsal sacrum ITB, gluteal tu- Inferior Extend, ER Detached in posterior gemellus berosity (femur) gluteal thigh approach to hip Obturator Exits through lesser internus Ischiopubic rami, ob- Trochanteric Obturator ER thigh sciatic foramen Inferior ge- Detached in posterior mellus turator membrane fossa approach to hip Quadratus Ascending br. medial femoris Short External Rotators circumflex artery under muscle Anterior sacrum Superior greater N. to ER thigh trochanter piriformis Ischial spine Medial greater N. to obtura- ER thigh trochanter tor internus Ischiopubic rami, ob- Medial greater N. to obtura- ER, abduct tor internus thigh turator mem. trochanter Ischial tuberosity Medial greater N. to quadra- ER thigh trochanter tus femoris Ischial tuberosity Intertrochanteric N. to quadra- ER thigh crest tus femoris NETTER’S CONCISE ORTHOPAEDIC ANATOMY 239