Triangular fibrocartilage complex tear with scapholunate advanced collapse and dorsal intercalated segment instability
Presentation
Previous trauma, wrist pain
Patient Data
Ulna styloid fracture, old. Widened scapholunate interval.
Previous history of wrist trauma. The ulnar styloid process fracture has formed a pseudo-arthrosis. The adjacent triangular fibrocartilage is grossly degenerate with a large central perforation. A small subcutaneous synovial cyst, 7 mm in diameter, along the ulna margin, communicates with the ulna-carpal joint space. The volar and dorsal radio-ulnar ligaments remain intact. There is ulnolunate abutment with loss of cartilage and minimal subadjacent bone and marrow edema. The scapholunate distance is widened at approximately 6 mm and there is a full-thickness perforation through the SL ligament. There is associated dorsal tilt of the lunate (the scapholunate angle measures 86 deg, normal is less than 60) and volar angulation of the scaphoid. Focal high signal within the distal capitate with a small subarticular cyst consistent with a focal osteochondral defect. Osteophyte formation is present around the base of the first metacarpal. Mild synovitis particularly along the dorsum of the wrist.
Comment:
- Pseudo-arthrosis of the ulnar styloid fracture with a grossly degenerative triangular fibrocartilage.
- Full thickness scapholunate ligamentous disruption and early SLAC.
- Little evidence of active synovitis.
Case Discussion
SLAC refers to scapholunate advanced collapse and can be due to previous trauma or spontaneous osteoarthritis of the wrist.
DISI refers to dorsal intercalated segmental instability is due to disruption of the dorsal intercarpal ligament.