Three-Corner Fusion for Management of SNAC and SLAC Wrists

Abstract

Objective: Presenting the results of fusion of the lunate bone with capitate and hamate bones plus excision of scaphoid and triquetrum in management of scaphoid nonunion advanced collapse (SNAC) and scapholunate advanced collapse (SLAC) wrists, looking in particular at the resulted range of wrist motion. Hypothesis: Four corners fusion is considered the golden standard treatment of SNAC and SLAC wrists in the last decade. It is designed to result in relieving pain while maintaining a reasonable hand grip power and preserving some wrist mobility. Yet, many of the candidates wished to have a better arc of wrist movements. Materials and Methods: In a longitudinal study, 3 corner fusion procedure has been performed in 18 patients (12 had SNAC wrists and 6 had SLAC arthritis). Whereas, fusion between lunate, capitates, and hamate was performed together with excision of both of scaphoid and triquetral bones. Also excision of 3 to 4 mm of the radial styloid was carried out for all cases. Results: To date, all cases that were operated with this procedure eventually go into union in a period between 8 to 10 weeks. After an average followed-up period of 19 months (range, 13 to 40 months), the mean of flexion-extension arc of motion of their wrists decreased from 67% (preoperatively) to 62% (postoperatively) compared with the opposite side (range, 55% to 74%). The mean postoperative grip strength increased from 52% to 78% of the opposite side (range, 62% to 100%). None of the patients needed any further surgery and 75% were satisfied and 25% were pleased with the results. Conclusions: Results of 3 corner fusion are promising. The resulted range of wrist motion is relatively better than that obtained with 4 corner fusions, while grip strength and other clinical parameters are yet comparable.