Review Question - QID 4595

The integrity of the dorsal intercarpal ligaments is important in preventing dorsal intercalated segment instability (DISI) deformity and persistent scapholunate instability.

Scapholunate instability is the most common carpal instability. The primary stabilizing structure of the scaphoid and lunate bones is the scapholunate ligament, which is commonly injured with a fall on an outstretched hand. Secondary stabilizers of the scaphoid and lunate include the dorsal intercarpal ligaments and the dorsal radiocarpal ligaments. Failure to recognize injury of these structures can cause persistent dorsal intercalated segment instability (DISI). This can predispose patients to a SLAC wrist and early wrist osteoarthritis.

Mitsuyasu et al. examined the role of dorsal intercarpal ligaments (DIC) in scapholunate instability. They showed that the DIC had an important role in stabilizing the scaphoid and lunate bones with static and dynamic movements. The authors of this study suggest that the DIC ligament should be assessed intraoperatively and consideration should be given to repair and/or reconstruction with surgical management of scapholunate ligament tears.

Viegas et al. showed that the dorsal intercarpal and the dorsal radiocarpal ligaments form a lateral V configuration over the dorsal wrist. This configuration acts as an indirect dorsal stabilizing effect on the scaphoid throughout the range of motion of the wrist. Their integrity acts to ensure normal wrist kinematics.

Figure A shows an AP and lateral radiograph of the left hand. There is significant gapping between the scaphoid and lunate articulation. This is indicative of a complete scapholunate dissociation, however both wrists should be imaged as this deformity may exist without injury. Illustration A shows the anatomy of the dorsal intercarpal and the dorsal radiocarpal ligaments.

Incorrect Answers:
Answers 1, 3, 4, 5: Carpal ligamentous injuries can occur with falls onto an outstretched hand. However, the clinical and radiographic features of this patient do not show injury to these structures.