Carpal ligamentous injuries
With thanks to Yusuf.
Fall on outstretched hand (FOOSH) can cause several carpal ligamentous injuries. These occur in 4 sequential stages, beginning with scapholunate joint dislocation and proceeding around the lunate causing progressive carpal instability.
Stage I – scapholunate dislocation – widening of scapholunate joint (the “Terry Thomas” or “Madonna” sign)
Stage II – perilunate dislocation (capitate is posteriorly dislocated but the lunate remains articulated with the radius); look for associated scaphoid and ulnar styloid fractures
Stage III – stage II injury + dislocated triquetrum; can be associated with a volar triquetral fracture
Stage IV – lunate dislocation (from both radius and capitate)
All need early reduction and Orthopaedics referral.