DISTAL RADIOULNAR LIGAMENT MOTION DURING SUPINATION AND PRONATION

The dorsal and palmar distal radio-ulnar ligaments (DRUL) play an impo rtant role in the stability of the distal radio-ulnar joint (DRUJ). Va rious authorities, however, hold opposite opinions regarding DRUL moti on during DRUJ pronation and supination, thus implying opposite techni ques for reconstruction of the unstable DRUJ. With the hypothesis that relative displacement would increase in the dorsal DRUL during pronat ion and would increase in the palmar DRUL during supination, measureme nts were made of the relative DRUL displacement with a Hall-effect dis placement transducer during DRUJ pronation and supination in six fresh cadaver wrists. The hypothesis was confirmed that the dorsal radio-ul nar ligament undergoes relative displacement during pronation, while t he palmar radio-ulnar ligament undergoes relative displacement during supination.