The relationship between the posterior radioscaphoid angle and the severity of cartilage damage and scapholunate diastasis after scapholunate ligament tears

Abstract

Purpose: Post-traumatic scapholunate interosseous ligament (SLIL) tears may lead to scapholunate dissociation, especially when associated with extrinsic ligament injury. Because the lunate is unrestrained by the scaphoid after SLIL tears, a dorsal intercalated segment instability (DISI) pattern is often established overtime, with dorsal tilt of the lunate and volar tilt of the scaphoid. DISI is responsible for abnormal joint kinematics and excessive loading through the radial side of the wrist joint, leading to degenerative arthritis at the radioscaphoid joint, followed by carpal collapse, and midcarpal osteoarthritis (scapholunate advanced collapse - SLAC - wrist).