What is the main function of the triangular fibrocartilage complex (TFCC)?
The triangular fibrocartilage complex transmits axial load between carpus and ulna and is an important factor in ulnar-sided stability and the stability of the distal radioulnar joint in particular.
What are the main components of the triangular fibrocartilage complex?
The triangular fibrocartilage complex basically consists of a fibrocartilaginous disc (the articular disc or disc proper) a low vascularized structure and a number of different better-vasularized ligaments, the triangular ligament (styloid and foveal insertion), the volar and dorsal radioulnar ligaments, the ulnolunate and ulnotriquetral ligament the meniscal homologue, the ulnar collateral ligament and the extensor carpi ulnaris subsheath.
Why are peripheral lesions of the triangular fibrocartilage complex more amenable to surgery than the articular disc or "disc proper"?
The periphery of the triangular fibrocartilage complex is better vascularized than the central portion and radial attachment and thus can better heal once repaired, while those in the central avascular zone cannot. The TFCC receives its main arterial blood supply from branches of the ulnar artery and the palmar and dorsal branches of the anterior interosseous artery.
Coronal and axial fat-saturated intermediate weighted images show severely oedematous and thickened dorsal radioulnar ligament and signal change of the proximal lamina of the triangular ligament (foveal attachment).
Focal bone marrow oedema of the ulnar head, adjacent to the foveal attachment.
The ulnotriquetral ligament is intact.
Sagittal fat-saturated intermediate weighted images indicate detachment of the triangular fibrocartilage complex (TFCC) at the dorsal radioulnar ligament.
Joint effusion in the distal radioulnar joint (DRUJ) with free intra-articular body/fragment within the palmar recess of the distal radioulnar joint visible in axial images.
Fat-saturated T1w images show contrast enhancement of the foveal attachment as well as dorsal radioulnar ligament indicative of reparative fibrovascular tissue.
Additional findings:
Scapholunate and lunotriquetral ligaments are intact.