Ulnar collateral ligament of wrist joint

The ulnar collateral ligament of the wrist (UCL; Ulnotriquetral ligament) is a ligamentous component located on the ulnar (medial) aspect of the wrist that is considered an integral part of the triangular fibrocartilage complex (TFCC), rather than a discrete, independently dissectable structure. It extends from the tip or medial base of the ulnar styloid process distally toward the ulnar carpus (triquetrum, and variably the hamate and base of the fifth metacarpal), functioning to reinforce the ulnar side of the wrist joint and contribute to ulnocarpal stability.