The biomechanical effects of surgical treatment options for Kienböck's disease have been compared. However, no study has included a direct analysis of capitate shortening along with capitate-hamate fusion (CSCHF). To investigate the biomechanical effects of CSCHF, a cadaver model of the upper extremity was used to determine radiocarpal articular pressure changes resulting from this procedure using pressure-sensitive film. Ten specimens were tested by placing each in an apparatus that applied load across the radiocarpal joint through the wrist flexor and extensor tendons. Testing was performed in 3 wrist positions (ulnar deviation, radial deviation, and neutral) combined with 3 forearm positions (pronation, supination, and neutral) and neutral flexion/extension. Radioscaphoid, radiolunate, and mean contact pressures in the entire radiocarpal joint were determined for each of the 9 wrist positions, both intact and after surgery. The radioscaphoid mean pressure increased in 6 of 9 positions and was unchanged in 3 positions. The radiolunate mean pressure decreased in 9 of 9 positions. The radiocarpal mean pressure increased in 2 of 9 positions and was unchanged in 7 positions. These data suggests that CSCHF increases radioscaphoid mean pressure, decreases radiolunate mean pressure, and has little effect on radiocarpal mean pressure.