Components of triangular fibrocartilage complex. AD, Articular disc; MH, meniscus homologue; RUL, dorsal and volar radioulnar ligaments; UCL, ulnar collateral ligament. Other structures shown are metacarpal bones (1, 2, 3, 4, and 5), carpal bones (C, capitate; H, hamate; L, lunate; S, scaphoid; Td, trapezoid; Tm, trapezium; Tq, triquetrum), radius ®, and ulna (U).