Posterior Perspective of the Triquetrum

Description

Posteriorly, the triquetrum sits on the ulnar side of the proximal carpal row, distal to the distal ulna and triangular fibrocartilage complex region and proximal to the hamate. Its dorsal surface appears relatively flat compared with the more contoured palmar aspect, while the lunate lies radial to it and the pisiform overlies it on the palmar side (not visible from a true dorsal view). Distal metacarpals and the phalanges extend distally from the carpus, and the distal radius and ulna frame the proximal carpal row in the forearm-hand junction. A posterior perspective of the triquetrum matters because dorsal-sided ulnar wrist pain is often localized clinically by palpation just distal to the ulnar styloid, where the triquetrum articulates with the lunate and hamate and can be a source of mechanical symptoms. Dorsal triquetral avulsion fractures are common after a fall on an extended wrist and can be subtle on standard posteroanterior radiographs, sometimes requiring a lateral view or cross-sectional imaging to confirm the dorsal chip fragment. Clear orientation of the triquetrum relative to the lunate and hamate also supports teaching of carpal stability patterns, including ulnar-sided perilunate injury mechanisms. Orthopedic and radiology educators can place this view alongside PA, lateral, and oblique wrist projections to teach why a dorsal cortical fragment may be missed when the carpal arcs are otherwise preserved. Hand surgery texts and emergency medicine modules on wrist trauma can use it to anchor surface anatomy for dorsal ulnar tenderness and to distinguish triquetral injury from hamate or distal ulna pathology. Anatomical accuracy verified by SciePro's Medical Advisory Board.