The Hip - book
Home » Muscles Tendons » Anatomy and Function of the Triangular Fibrocartilage Complex

Anatomy and Function of the Triangular Fibrocartilage Complex



- See: Ligaments of the Wrist

- Anatomy of TFCC:
    - consists of articular disc (triangulyar fibrocartilage), meniscus homologue (lunocarpal), ulnocarpal ligament, dorsal & volar radioulnar ligament, and ECU sheath;
    - it originates from firm attachments on medial border of distal radius and inserts into the base of the ulnar styloid;
    - it separates the radiocarpal from the distal radioulnar joint;
    - thickness of TFCC is roughly 5 mm at ulnar side and 2 mm thick at radial side;
    - vascular anatomy: only the peripheral 15-20% of the TFCC has a blood supply;
    - ligamentous attachements: (see ligament of the wrist)
           - ulnar attachment of the TFCC is anchored by two bands inserting to the styloid process and fovea (base of the styloid);
           - volar ulnocarpal ligaments run from the base of the ulnar styloid process across the volar surface of the TFCC, and then insert on the lunate and triquetrum;
           - ulnocarpal ligaments include:
                   - volar ulnolunate:
                   - ulnotriquetral ligaments:
           - these ligaments prevent dorsal migration of the distal ulna;
           - because the ulnar styloid moves away from the carpi in supination, these ligaments are more taught in supination;
    - blood supply:
           - central disk is avascular;
           - peripheral vessels penetrate approximately 10-40% of the TFCC margins;

- Function:
    - TFCC is main stabilizer of distal radioulnar joint, in addition to contributing to ulnocarpal stability;
           - its important in loading & stabilizing of distal radioulnar joint;
           - TFCC normally not only stabilizes the ulnar head in sigmoid notch of radius but also acts as a buttress to support proximal carpal row;
    - during axial loading, the radius carries the majority of load (82%), and the ulna a smaller load (18%);
           - increasing the ulnar variance to a positive 2.5 mm increases the load transmission across the TFCC to 42%;
           - w/ the TFCC excised, the radial load increases to 94%;
    - stabilizing role: (see DRUJ instability)
           - volar TFC prevents dorsal displacement of ulna and is tight in pronation;
           - dorsal TFC prevents volar displacement of ulna and is tight in supination



An anatomic study of the ligamentous structure of the triangular fibrocartilage complex.

The triangular fibrocartilage complex: an important pulley for the ulnar wrist extensor.

The microvasculature of the triangular fibrocartilage complex: Its clinical significance.

Histologic anatomy of the triangular fibrocartilage.