Pressure mapping of the radioulnar carpal joint: Effect of ulnar lengthening and wrist position

The purpose of this study was to investigate the effects of ulnar lengtheni ng and wrist position on force transmission through the radioulnar carpal j oint in a forced dorsiflexed wrist position, Eight cadaveric arms were subj ected to a 30 kg compressive load directed down the forearm towards the wri st, A pressure sensor recorded forces across the wrist joint with the trian gular fibrocartilage complex intact and excised. The biomechanics of the di stal radioulnar joint were altered bg changes in ulnar length and wrist pos ition. Pressures at the ulnolunate articulation increased as the ulna was l engthened and were significantly lower when the triangular fibrocartilage c omplex,vas excised, An inverse relationship between triangular fibrocartila ge complex thickness and ulnar variance was shown. Greater increases in uln olunate pressure were observed in more positive ulnar variant wrists.