NORMAL ANATOMY Ossification order of ossification (clockwise in a right hand starting at capitate): capitate, hamate, triquetrum, lunate, scaphoid, trapezium, trapezoid, pisiform Osteology Palmar/volar view Dorsal view Ligaments Palmar/volar view Dorsal view Carpal (Gilula's) arcs Proximal = proximal scaphoid + lunate + triquetrum Middle = distal scaphoid + lunate + triquetrum Distal = proximal capitate + hamate RADIOGRAPHIC VIEWS AP/PA view Positioning patient shoulder abducted 90°+ elbow flexed 90° + forearm/hand supinated (AP) vs. pronated (PA) beam aim at mid-carpus Indications carpal joints = AP view preferred over PA view radiocarpal joint distal radius/ulnar fracture Critique foreshortened scaphoid trapezoidal lunate slight superimposition of distal radius + carpal bones open 2nd-5th CMC joints Lateral view Positioning patient shoulder adducted + elbow flexed 90° + forearm neutral beam aim at mid-carpus + 10° cephalad Indications alignment of bones/joints carpal/lunate instability Critique volar cortex of pisiform + capitate within central 1/3 of volar scaphoid visualization of ulnar styloid posteriorly important to adduct shoulder to achieve adequate rotation of ulna ulna does not rotate with pronation/supination Oblique view Positioning patient shoulder abducted 90°+ elbow flexed 90° IR oblique = forearm pronated 45° ER oblique = forearm supinated 45° beam aim at mid-carpus Indications IR oblique = radial carpal bones ER oblique = ulnar carpal bones Critique IR oblique no superimposition of trapezoid + trapezium slight superimposition of trapezoid + capitate open trapezium-trapezoid + scaphotrapezium + 2nd CMC joints ER oblique no superimposition of triquetrum, lunate, or pisiform Ulnar/radial deviation view Positioning patient shoulder abducted 90° + elbow flexed 90° + forearm pronated + hand ulnarly vs. radially deviated beam aim at scaphoid Indications ulnar deviation = lateral wrist + scaphoid fracture radial deviation = medial wrist Critique characteristic movement of scaphoid/lunate ulnar deviation = extends radial deviation = flexes Carpal bridge/tunnel view Positioning METHOD PATIENT BEAM Original carpal bridge elbow extended + forearm pronated + wrist extended 4cm proximal to bend of wrist 45° caudad Modified carpal bridge elbow flexed + wrist extended 4cm proximal to bend of wrist 45° caudad Carpal tunnel elbow flexed + forearm pronated + wrist extended 2.5cm distal to base of 3rd metacarpal 25-30° cephalad Indications pisiform fracture trapezium fracture hook of hamate fracture Critique visualization of carpal tunnel Clenched fist view Positioning patient elbow flexed 90° + forearm supinated + wrist ulnarly deviated + hand clenched to move capitate proximally beam aim at mid-carpus usually obtain bilateral wrists Indications SL injury Critique if obtaining bilateral wrists, symmetric positioning of bilateral wrists Scaphoid view Positioning patient elbow flexed + forearm pronated + wrist extended 30° and ulnarly deviated 20° beam aim at mid-wrist Indications scaphoid fracture Trapezium (Clements-Nakayama) view Positioning patient elbow flexed + forearm pronated 45° + wrist ulnarly deviated beam aim at snuffbox/trapezium if unable to ulnarly deviate wrist, aim 20° cephalad Indications trapezium fracture NORMAL FINDINGS Normal radiographic appearance PA view Lateral view Oblique view Scaphoid view Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate Normal variants lunula located within TFCC between ulnar styloid + triquetrum can be fused to ulnar styloid, resulting in elongated shape os triangulare located between ulnar styloid + lunate + triquetrum os hamuli proprium accessory bone resulting from failure of fusion of hook of hamate ossification center os centrale carpi located dorsally between scaphoid + trapezoid + capitate os epilunate located at dorsal aspect of lunocapitate joint os styloideum located between 2nd and 3rd metacarpal bases os paratrapezium located between distal radial aspect of radius + base of 1st metacarpal os radiostyloideum located near radial styloid process and lateral to mid-portion of scaphoid CLINICAL PEARLS Amsterdam wrist rules XRs are indicated if any of the following criteria are met increased age wrist swelling visible deformity TTP at distal radius if suspected distal radius fracture pain with palmarflexion pain with supination painful radioulnar ballottement test pain with ulnar deviation = decreased risk if suspected wrist fracture M > F anatomical snuffbox swelling pain with radial deviation painful axial compression of thumb = decreased risk Wrist effusion pronator quadratus fat pad sign bowing of fascial covering of pronator quadratus seen on lateral view scaphoid fat pat sign seen on ulnar deviation view Scaphoid fracture Classification waist = 65% proximal 1/3 = 25% distal 1/3 = 10% most common in peds due to ossification pattern Recommended views PA visualizes the proximal pole but provides distorted image of waist and distal pole due to flexed position of scaphoid lateral visualizes the waist of scaphoid but is limited by overlap of carpal bones scaphoid view 30° wrist extension, 20° ulnar deviation IR oblique best view to see the waist and distal pole of scaphoid if radiographs are negative and there is a high clinical suspicion, repeat radiographs in 14-21 days Optional views clenched fist if concern for scapholunate ligament injury Findings unstable scaphoid fractures humpback deformity displacement > 1 mm on any view scapholunate angle > 60° radiolunate angle > 15° intrascaphoid angle > 35° Treatment criteria nonoperative treatment acceptable if stable nondisplaced fracture (majority of fractures) if patient has normal xrays but there is a high level of suspicion can immobilize in thumb spica and reevaluate in 12 to 21 days ORIF if unstable fractures proximal pole fractures displacement > 1 mm 15° scaphoid humpback deformity radiolunate angle > 15° (DISI) intrascaphoid angle of > 35° scaphoid fractures associated with perilunate dislocation comminuted fractures unstable vertical or oblique fractures non-displaced waist fractures Lunate dislocation (perilunate dissociation) Classification = Mayfield Mayfield Classification Stage I • scapholunate dissociation Stage II • + lunocapitate disruption Stage III • + lunotriquetral disruption, "perilunate" Stage IV • lunate dislocated from lunate fossa (usually volar) • associated with median nerve compression Recommended views PA lateral Findings PA break in Gilula’s arc overlap of lunate + capitate "piece-of-pie sign" triangular appearance of lunate due to palmar rotation from dorsal force of carpus lateral loss of colinearity of radius, lunate, and capitate in stage III injury, capitate displaces dorsal to lunate in stage IV injury, lunate displaces volar to radius to form "spilled teacup sign" scapholunate angle > 70° spilled teacup sign Treatment criteria nonoperative treatment NOT acceptable emergent closed reduction/splinting followed by open reduction, ligament repair, fixation, possible carpal tunnel release if acute injury (< 8 weeks) proximal row carpectomy if chronic injury (> 8 weeks) total wrist arthrodesis if chronic injury with degenerative changes Triquetrum fracture Classification Triquetrum Fractures Dorsal cortical fractures • most common (accounts for up to 93%) • mechanism includes avulsion, shearing force, or impaction Body fractures • second most common • subtypes: sagittal, medial tuberosity, transverse proximal pole, transverse body, comminuted Palmar cortical fractures • mechanism includes avulsion or shearing force • risk of instability Recommended views PA lateral useful for visuzalizing dorsal cortical fractures IR oblique useful for visuzalizing dorsal cortical fractures Optional views radial deviation may be helpful in identifying palmar cortical fractures Findings "pooping duck" sign represents dorsal cortical fractures Treatment criteria nonoperative treatment acceptable if dorsal cortical fractures without evidence of instability nondisplaced body fractures palmar cortical fractures without evidence of instability ORIF if dorsal cortical fractures with evidence of instability displaced body fractures palmar cortical fractures with evidence of instability Hook of hamate fracture Classification = Milch Milch Classification Description Subtypes Image Type I Hook of hamate fx (most common) • I - avulsion • II - middle of hook • III - base of hook Type II Body of hamate fx • IIA - coronal • IIB - transverse Recommended views PA lateral ER oblique carpal tunnel best view to see hook of hamate fractures Findings PA view absence of eye sign of cortical ring normally produced by intact hook sclerosis in region of the hook Treatment criteria nonoperative treatment acceptable in most cases excision if chronic non-union Hamate body fracture Classification = Milch Milch Classification Description Subtypes Image Type I Hook of hamate fx (most common) • I - avulsion • II - middle of hook • III - base of hook Type II Body of hamate fx • IIA - coronal • IIB - transverse Recommended views PA lateral ER oblique best view to see hamate body fractures carpal tunnel Treatment criteria nonoperative treatment acceptable if extra-articular and non-displaced (rare) ORIF if extra-articular and displaced intra-articular Pisiform fracture Recommended views PA lateral ER oblique carpal tunnel best seen with ER oblique or carpal tunnel view Treatment criteria nonoperative treatment acceptable in most cases pisiformectomy if severely displaced and symptomatic fractures painful nonunion
Trapezial Body Fracture in 17M (C101463) Austin Pitcher Hand - Wrist Trauma Radiographic Evaluation C 5/17/2020 56 0 0