Functional outcomes after the Sauvé-Kapandji procedure for distal radio-ulnar post-traumatic instability: a case-control comparison of three different operative methods of stabilization of the ulnar stump.

PURPOSE: This study was performed to elucidate the cause of proximal ulnar stump pain by comparing the clinical results and radiographic changes among three treatment groups involving different Sauvé-Kapandji procedures.

METHODS: Thirty-seven patients (38 wrists) with distal radioulnar joint disorders followed up for ≥ six months post-operatively were investigated. Patients were treated by one of three Sauvé-Kapandji procedures. In group A (13 wrists), the original Sauvé-Kapandji procedure was performed. Groups B (13 wrists) and C (12 wrists) involved different modified Sauvé-Kapandji procedures with stabilization of the proximal ulnar stump using the extensor carpi ulnaris tendon. At the final examination, we evaluated wrist pain, proximal ulnar stump pain, the ranges of forearm pronation/supination, grip strength, the grip strength ratio between the affected and unaffected sides, and the clinical evaluation score. Standard posteroanterior and lateral radiographs during rest and during maximal gripping were taken for each patient at the final examination, and radiographic parameters were measured.

RESULTS: Although significant differences in the frequency of ulnar stump pain were observed between group A and group B or C, no significant differences in wrist pain or the clinical evaluation score were observed. Moreover, no differences in the radiographic changes were noted among the three procedures.

CONCLUSION: These findings suggest that proximal ulnar stump pain may be caused not by radial or dorsal deviation of the proximal ulnar stump but by other dynamic factors.