Presentation
Left wrist pain and limitation.
Patient Data
Scapholunate dissociation with increased distance (5 mm) between the scaphoid and the lunate bones (Terry Thomas sign). Proximal migration of the capitate bone.
Dorsally tilted lunate axis with increased scapholunate angle and capitolunate angles.
Those findings are compatible with Dorsal intercalated segment instability (DISI).
Degenerative changes of the radioscaphoid and intercarpal joints (most evident at the radioscaphoid joint) evident by narrowing of the joint spaces, subarticular sclerotic and pseudocystic changes.
Multiple small intra-articular loose bodies.
Those findings are impressive of Scapholunate advanced collapse (SLAC) stage (IV)
Case Discussion
Scapholunate advanced collapse (SLAC) refers to a pattern of the malignment of the carpal bones that can be post-traumatic or spontaneous. It can be a complication of undiagnosed or untreated scapholunate dissociation. This case shows the Terry Thomas sign of increased distance between the scaphoid and lunate. The normal distance is at most 4 mm.