NORMAL ANATOMY Ossification Carpal bones order of ossification (clockwise starting at capitate): capitate, hamate, triquetrum, lunate, scaphoid, trapezium, trapezoid, pisiform Metacarpals Phalanges Osteology & Attachments Palmar/volar view Dorsal view Radial view Arches Arches of the Hand Arch Components Keystone Proximal transverse distal carpal bones capitate Distal transverse MCP joints 2nd and 3rd MCP joints Longitudinal 2nd and 3rd rays 2nd and 3rd MCP joints RADIOGRAPHIC VIEWS PA view Positioning patient shoulder abducted + elbow flexed 90° + hand flat on plate beam aim at 3rd MCP joint Critique 45° oblique view of thumb equal amount of soft tissue on both sides of digits equal spacing of metacarpal heads symmetrical concavity of metacarpal/phalangeal shafts fingernails centered no soft tissue overlap of adjacent digits open CMC + MCP + IP joint spaces Lateral view Positioning patient shoulder abducted + elbow flexed 90° + hand supinated + thumb abducted beam aim at 3rd MCP joint Indications phalanx dislocations = preferred view Critique superimposition of digits + metacarpal shafts can pronate 30° to see 4th/5th CMC Fx/dislocation can supinate 30° to see 2nd/3rd CMC Fx/dislocation ulna located slightly posterior to radius open IP joints Lateral fan view Positioning patient shoulder abducted + elbow flexed 90° + hand supinated + fingers spread out beam aim at 3rd MCP joint Critique minimal superimposition of digits superimposition of metacarpal shafts ulna located slightly posterior to radius open IP joints Oblique view Positioning patient shoulder abducted + elbow flexed 90° + forearm neutral IR oblique = hand pronated 45° ER oblique = hand supinated 45° beam aim at 3rd MCP joint Indications IR oblique = 4th/5th CMC fracture/dislocation ER oblique = 2nd/3rd CMC fracture/dislocation Critique ER oblique asymmetrical concavity of metacarpal shafts + intermetacarpal spaces no superimposition of 2nd + 3rd metacarpal slight superimposition of 3rd-5th metacarpal heads no soft tissue overlap of adjacent digits open IP + MCP joints Ballcatcher's (Norgaard) view Positioning patient hands supinated 45° beam obtain bilateral hands aim between hands at level of MCP joints Indications hand pathology in RA = esp. early erosions in corners of P1 bases Critique no superimposition of metacarpal shafts + bases of phalanges open MCP joints Brewerton view Positioning patient elbow extended + forearm supinated + MCPs flexed 60° beam aim at head of 3rd metacarpal + 20° ulnar-to-radial Indications fixed flexion deformities collateral ligament avulsion Fx metacarpal head Fx Critique symmetrical 2nd-5th metacarpal shafts open IP + MCP joints Roberts view Positioning patient forearm/hand hyperpronated + thumb flat on plate beam aim at MCP joint Indications thumb fractures Critique symmetrical concavity of phalangeal shaft equal amount of soft tissue on both sides of digit fingernail centered soft tissue overlap of palm over midshaft of 1st metacarpal + CMC joint open CMC joint Joint folio (skier's thumb) view Positioning patient hands pronated + thumbs with rubberband around IP joints beam obtain bilateral hands aim between hands at level of MCP joints Indications 1st CMC joint UCL rupture Critique symmetrical concavity of metacarpal + phalangeal shafts open IP + MCP joints NORMAL FINDINGS Normal variants 5th metacarpal pit exaggerated pit-like depression in 5th metacarpal head spade phalanx hypertrophy of terminal phalangeal tufts can be associated with acromegaly or macrodactyly CLINICAL PEARLS Metacarpal fracture Classification head neck shaft Recommended views PA lateral ER oblique best view to see 4th/5th CMC fracture/dislocation IR oblique best view to see 2nd/3rd CMC fracture/dislocation Optional views brewerton best view to see metacarpal head fractures roberts best view to see thumb CMC fracture/dislocation Treatment criteria nonoperative treatment acceptable if Acceptable Shaft Angulation (degrees) Acceptable Shaft Shortening (mm) Acceptable Neck Angulation (degrees) Index & Long Finger 10-20 2-5 10-15 Ring Finger 30 2-5 30-40 Little Finger 40 2-5 50-60 CRPP vs. ORIF if open fracture intra-articular fracture rotational malalignment of digit significantly displaced or angulated fractures (see above criteria) multiple metacarpal shaft fractures loss of inherent stability from border digit during healing process ex-fix vs. MCP arthroplasty if severely comminuted metacarpal head fracture MCP dislocation Classification anatomic volar results from hyperextension or hyperflexion injury dorsal more common results from hyperextension injury complexity simple (subluxation) no interposition of volar plate and/or sesamoids base of proximal phalanx remains in contact with metacarpal head complex (complete) interposition of volar plate and/or sesamoids metacarpal head becomes entrapped by displaced natatory ligaments distally superficial transverse metacarpal ligament proximally Kaplan's lesion (rare) most common in index finger metacarpal head buttonholes into palm (volarly) volar plate is interposed between base of proximal phalanx and metacarpal head Recommended views AP lateral best view to see dislocation oblique Findings complex dislocation joint space widening may indicate interposition of volar plate entrapment of sesamoid in MCP joint is diagnostic of complex dislocation Treatment criteria nonoperative treatment acceptable if simple dislocation open reduction if complex dislocation Phalanx fracture Recommended views PA lateral oblique Findings proximal phalanx apex volar angulation due to proximal fragment pulled into flexion by interossei distal fragment pulled into extension by central slip middle phalanx apex volar angulation if distal to FDS insertion apex dorsal angulation if proximal to FDS insertion Treatment criteria nonoperative treatment acceptable if distal phalanx fracture if no nailbed injury middle or proximal phalanx fracture if extraarticular with < 10° angulation or < 2mm shortening and no rotational deformity nailbed repair if distal phalanx fracture with nailbed injury CRPP vs. ORIF irreducible or unstable fracture pattern transverse fractures with > 10° angulation or 2mm shortening or rotationally deformed long oblique proximal phalanx fracture non-union of distal phalanx fracture Seymour fracture Recommended views PA may appear normal lateral Findings widened physis or displacement between epiphysis/metaphysis flexion deformity at fracture site seen on lateral view Treatment criteria nonoperative treatment acceptable if minimally displaced, closed fracture no interposition of soft tissue at fracture site closed reduction and pinning across DIPJ if displaced, closed fracture no interposition of soft tissue at fracture site antibiotics, open reduction and pinning across DIPJ, nailbed repair if open fracture Phalanx dislocation Classification PIP joint dorsal dislocations simple middle phalanx in contact with condyles of proximal phalanx complex base of middle phalanx not in contact with condyle of proximal phalanx, bayonet appearance volar plate acts as block to reduction with longitudinal traction dorsal fracture-dislocations = Hastings (based on amount of P2 articular surface involvement) type I = < 30% involvement, stable type II = 30-50% involvemen, tenuous type III = > 50% involvement, unstable volar dislocation volar fracture-dislocation rotatory dislocations DIP joint dorsal dislocations & fracture-dislocations Recommended views PA may appear normal lateral oblique Findings V sign Treatment criteria dorsal PIPJ dislocation nonoperative treatment acceptable if simple dislocation open reduction if complex dislocation dorsal PIPJ fracture-dislocation nonoperative treatment acceptable if < 40% joint involvement and stable ORIF vs. CRPP if > 40% joint involvement and unstable dynamic distraction external fixation if highly comminuted "pilon" fracture-dislocations volar plate arthroplasty vs. arthrodesis if chronic injury volar PIPJ dislocation and fracture-dislocation nonoperative treatment acceptable if volar PIPJ dislocation volar PIPJ fracture-dislocation if < 40% joint involvement and stable nonoperative treatment acceptable if volar PIPJ dislocation dorsal PIPJ dislocation if simple volar/dorsal PIPJ fracture-dislocation if < 40% joint involvement and stable dorsal DIPJ dislocation/fracture-dislocation open reduction if dorsal PIPJ dislocation if complex rotatory PIPJ dislocation dorsal DIPJ dislocation/fracture-dislocation if 2 failed attempts at reduction ORIF vs. CRPP if volar/dorsal PIPJ fracture-dislocation if > 40% joint involvement and unstable dynamic distraction external fixation if highly comminuted "pilon" dorsal PIPJ fracture-dislocation volar plate arthroplasty vs. arthrodesis if chronic dorsal PIPJ fracture-dislocation volar PIPJ dislocation Digital collateral ligament injury Classification UCL injury RCL injury Recommended views PA lateral oblique varus/valgus stress views may aid in diagnosis Treatment criteria nonoperative treatment acceptable for most injuries collateral ligament repair if RCL injury of index finger (ligament needed for pinch stability) Base of thumb fracture Classification intra-articular bennett fracture-dislocation with volar lip of metacarpal based attached to volar oblique ligament rolando fracture with intra-articular comminution extra-articular Recommended views PA lateral oblique roberts Findings bennett fractures small fragment of 1st metacarpal base articulating with trapezium rolando fractures Y sign represents spliting of 1st metacarpal base into volar and dorsal fragments Treatment criteria bennettt fractures nonoperative treatment acceptable if non-displaced CRPP if volar fragment is too small to hold a screw anatomic reduction unstable ORIF if large fragment > 2mm displacement rolando fractures nonoperative treatment acceptable if severe comminution and stable CRPP vs. ex-fix if severe comminution and unstable ORIF in most cases extra-articular fractures nonoperative treatment acceptable if < 30° angulation CRPP if > 30° angulation Thumb CMC dislocation Recommended views PA lateral Optional views roberts used to evaluate for base of thumb fractures Findings joint space widening slight dorsoradial shift of metacarpal Treatment criteria nonoperative treatment acceptable if stable after reduction CRPP vs. reconstruction of the dorsal capsuloligamentous complex with tendon autograft + temporary pinning if unstable after reduction Thumb collateral ligament injury Classification radial collateral ligament injury ulnar collateral ligament injury more common may have Stener lesion avulsed ligament with or without bony attachment is displaced above the adductor aponeurosis Recommended views PA lateral oblique Optional views joint folio may aid in diagnosis if a bony avulsion has already been ruled out Findings UCL injury avulsion or condylar fracture supination of proximal phalanx volar subluxation of proximal phalanx seen on lateral view indicates associated dorsal capsular tear or extensor tendon injury RCL injury pronation of proximal phalanx Treatment criteria nonoperative treatment acceptable if RCL tear partial UCL tears with < 20° side to side variation of varus/valgus instability ligament repair if acute injuries with > 20° side to side variation of varus/valgus instability >35° of opening Stener lesion reconstruction of ligament with tendon graft, MCP fusion, or adductor advancement if chronic injury