Dorsal wrist ligament insertions stabilize the scapholunate interval: cadaver study

This study examined sequential arthroscopic sectioning of volar, interosseous, and dorsal ligaments about the scapholunate complex in cadaver wrists. We attempted to clarify the contributions of the dorsal ligamentous complex to scapholunate instability and carpal collapse. We found that after sequential sectioning of volar ligaments and the scapholunate interosseous ligament, no scapholunate diastasis or excessive scaphoid flexion occurred. After dividing the dorsal intercarpal ligament, scapholunate instability occurred without carpal collapse. With sectioning of the dorsal radiocarpal ligament from the lunate, a dorsal intercalated scapholunate instability deformity ensued. This information may be of value in comprehending the pathogenesis of scapholunate instability and carpal collapse and in devising the rationales for conservative measures and surgical intervention.