The triangular fibrocartilage complex is a multi-structure stabiliser of the ulnar wrist consisting of the articular disc, dorsal and volar radioulnar ligaments, ulnocarpal ligaments, and ECU subsheath. It is the primary stabiliser of the distal radioulnar joint and the ulnar side of the wrist, absorbing approximately 20 percent of axial wrist load through the fibrocartilage disc. TFCC tears are the most common cause of ulnar-sided wrist pain in active individuals.
| Origin | Ulnar margin of the distal radius articular surface (sigmoid notch) |
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| Insertion | Base of the ulnar styloid, triquetrum, lunate, and hamate via the ulnocarpal ligaments |
| Actions | Primary stabiliser of the distal radioulnar joint during forearm rotation; cushions ulnar-sided wrist loading |
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TFCC tears are classified by Palmer into traumatic (Class I) and degenerative (Class II) subtypes. The foveal sign (tenderness between the FCU and ulna styloid over the TFCC) has good sensitivity. Wrist arthroscopy is both diagnostic and therapeutic, allowing tear classification, debridement of degenerative tears, and repair of peripheral tears with intact vascular supply. Positive ulnar variance (ulna longer than radius) increases TFCC load and accelerates degenerative tearing.
Traumatic or degenerative disruption of the triangular fibrocartilage complex producing ulnar-sided wrist pain reproduced by the foveal sign and wrist rotation, managed with arthroscopic debridement or repair.
