Distal scaphoid excision after radioscaphoid arthrodesis.

Radioscaphoid and radioscapholunate arthrodeses are effective surgical procedures for the treatment of nonsalvageable and isolated radiocarpal arthritis. These procedures, however, limit wrist motion significantly as the immobile scaphoid bridges the remaining midcarpal joint. A cadaver study of radioscaphoid arthrodesis followed by distal scaphoid excision was undertaken. Range of motion after radioscaphoid K-wire fixation alone demonstrated a 58% decrease in the preoperative flexion-extension arc to 60 degrees. After distal scaphoid excision (with the radioscaphoid pins still in place) the flexion-extension arc increased to 122 degrees or 86% of the preoperative range of motion; most of the increase in motion occurred at the midcarpal joint. Distal scaphoid excision releases the midcarpal joint following radioscaphoid fixation and results in a significantly greater wrist motion. If the results of this cadaver study are extrapolated to clinical practice the addition of this step to the previously described procedures of radioscaphoid or radioscapholunate arthrodesis addresses their major limitation, restricted motion.