[Scaphocapitate arthrodesis for chronic scapholunate instability: a retrospective study of 13 cases]

The management of chronic instability of the scapholunate joint is controversial. We have opted for scaphocapitate arthrodesis in such cases. The aim of this study was to analyse the clinical and radiological results of this procedure. Between 1997 and 2001, 13 scaphocapitate arthrodesis were performed for this indication. Eleven using two screws, one using a single screw plus a staple, and one using a single staple alone. The average age of the patients was 40 years. There were 8 sport accidents and 5 work accidents. The average follow-up was 26 months. We analysed the functional results and measured the height of the carpus and the radio-lunar angle radiographically. We noticed a mobility loss of between 20 and 40%, especially for radial tilt and flexion. The grip strength was improved. All the patients except one have some residual pain. We noted three non-unions which required revision with eventual final consolidation. The height of the carpus was improved. The average radio-lunar angle at follow-up was 16 degrees. Only one wrist remained in DISI. The mobility of the wrist was decreased by this procedure. In all these cases the dorsal approach to the wrist which we employed was bound to decrease the mobility. The radial tilt was decreased due to the partial arthrodesis. This procedure restore the height of the carpus and partially corrects the DISI. As we were not able to obtain a pain free wrist through our procedure, we raise the question as to whether a total neurectomy of the wrist should be performed at the same time.