Ossification order of ossification (counterclockwise in a right hand starting at capitate): capitate, hamate, triquetrum, lunate, scaphoid, trapezium, trapezoid, pisiform Order of ossification of the carpal bones Carpal bone Age at ossification (years) Age at fusion Capitate 1 14-16 Hamate 2 14-16 Triquetrum 3 14-16 Lunate 4 14-16 Scaphoid 5 14-16 Trapezium 5-6 14-16 Trapezoid 6-7 14-16 Pisiform 9-10 14-16 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 login to view 1 more bullet beam login to view 1 more bullet 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 login to view 1 more bullet beam login to view 1 more bullet 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 login to view 1 more bullet Oblique view Positioning patient login to view 3 more bullets beam login to view 1 more bullet Indications IR oblique = radial carpal bones ER oblique = ulnar carpal bones Critique IR oblique login to view 3 more bullets ER oblique login to view 1 more bullet Ulnar/radial deviation view Positioning patient login to view 1 more bullet beam login to view 1 more bullet Indications ulnar deviation = lateral wrist + scaphoid fracture radial deviation = medial wrist Critique characteristic movement of scaphoid/lunate login to view 2 more bullets Carpal bridge/tunnel view Positioning Carpal bridge/tunnel view positioning Method Patient position Beam position Original carpal bridge Elbow extended + forearm pronated + wrist extended 4cm proximal to bend of wrist45° caudad Modified carpal bridge Elbow flexed + wrist extended 4cm proximal to bend of wrist45° caudad Carpal tunnel Elbow flexed + forearm pronated + wrist extended 2.5cm distal to base of 3rd metacarpal25-30° cephalad Indications pisiform fracture trapezium fracture hook of hamate fracture Critique visualization of carpal tunnel Clenched fist view Positioning patient login to view 1 more bullet beam login to view 2 more bullets Indications SL injury Critique if obtaining bilateral wrists, symmetric positioning of bilateral wrists Scaphoid view Positioning patient login to view 1 more bullet beam login to view 1 more bullet Indications scaphoid fracture Trapezium (Clements-Nakayama) view Positioning patient login to view 1 more bullet beam login to view 2 more bullets Indications trapezium fracture NORMAL radiographic FINDINGS Normal radiographic appearance Normal radiographic appearance Bone 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 login to view 4 more bullets if suspected wrist fracture login to view 4 more bullets 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% login to view 1 more bullet Recommended views PA login to view 1 more bullet lateral login to view 1 more bullet scaphoid view login to view 1 more bullet IR oblique login to view 1 more bullet if radiographs are negative and there is a high clinical suspicion, repeat radiographs in 14-21 days Optional views clenched fist login to view 1 more bullet Findings unstable scaphoid fractures login to view 5 more bullets Treatment criteria nonoperative treatment acceptable if login to view 2 more bullets indications for ORIF login to view 10 more bullets Lunate dislocation (perilunate dissociation) Recommended views PA lateral Findings PA login to view 5 more bullets lateral login to view 5 more bullets 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 Recommended views PA lateral login to view 1 more bullet IR oblique login to view 1 more bullet Optional views radial deviation login to view 1 more bullet Findings "pooping duck" sign login to view 1 more bullet Treatment criteria nonoperative treatment acceptable if login to view 3 more bullets ORIF if login to view 3 more bullets Hook of hamate fracture Recommended views PA lateral ER oblique carpal tunnel login to view 1 more bullet Findings PA view login to view 3 more bullets Treatment criteria nonoperative treatment acceptable in most cases excision if chronic non-union Hamate body fracture Recommended views PA lateral ER oblique login to view 1 more bullet carpal tunnel Treatment criteria nonoperative treatment acceptable if extra-articular and non-displaced (rare) ORIF if login to view 2 more bullets 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 login to view 2 more bullets