The authors report their experience with scapholunate fusion in 13 patients with chronic, painful scapholunate instability. Their technique involved fixation of the scaphoid to the lunate with 1 or 2 Herbert screws and autogenous bone grafting. Radiographic consolidation was evident in only 4 cases at a mean of 7.8 years after surgery. Two patients eventually underwent a total wrist arthrodesis for treatment of recalcitrant wrist pain. Of the remaining 11 patients, 10 were interviewed and expressed satisfaction with their treatment. Nine of these patients were examined and demonstrated a mean wrist extension of 46 degrees, a mean wrist flexion of 41 degrees, and grip strength averaging 63% of the unaffected side. There were no cases of screw breakage, and only 1 case of subsequent degenerative arthritis developing at the radioscaphoid articulation.
Objections to attempted fusion of the scapholunate interval for treatment of symptomatic scapholunate instability include, 1) a small surface area between the scaphoid and lunate making bone union unpredictable, 2) expected loss of wrist motion, and 3) alterations in joint contact forces with the potential for secondary degenerative arthritis. Although bone union was confirmed in only 4 cases in this report, all patients who were interviewed expressed satisfaction with their treatment. A prospective study would be helpful in determining the potential benefits and drawbacks of this procedure over other techniques to address chronic, symptomatic scapholunate instability. It is clear that we still do not have a definitive answer for this relatively common carpal injury.
J Hand Surg 28B:311-14, 2003.