An anatomic study of the stabilizing ligaments of the trapezium and trapeziometacarpal joint

We provide a detailed and comprehensive anatomic description of the ligamen ts stabilizing the trapezium and trapeziometacarpal joint. Sixteen ligament s were identified. Fourteen ligaments inserted onto the trapezium and 2 oth ers attached independently to the thumb metacarpal. The ligaments inserting onto the trapezium were the superficial anterior oblique, deep anterior ob lique (beak ligament), dorsoradial, posterior oblique, ulnar collateral, do rsal trapezio-trapezoid, volar trapezio-trapezoid, dorsal trapezio-second m etacarpal, volar trapezio-second metacarpal, trapezio-third metacarpal, vol ar scaphotrapezial, radial scaphotrapezial, transverse carpal, and trapezio capitate ligaments. The remaining 2 ligaments attach onto the thumb metaca rpal and are the proper intermetacarpal and the dorsal intermetacarpal. The dorsoradial and deep anterior oblique ligaments play a substantial role in stabilizing the trapeziometacarpal joint, and the deep anterior oblique li gament may function as pivot for the first metacarpal during palmar abducti on to allow rotation (pronation). The dorsal trapezio-second metacarpal, vo lar trapezio-second metacarpal, and trapezio-third metacarpal ligaments fun ction as tension bands and are required to prevent instability from cantile ver bending forces on the trapezium. (J Hand Surg 1999;24A:786-798. Copyrig ht (C) 1999 by the American Society for Surgery of the Hand.).