[Four bone versus capito-lunate limited carpal fusion. Report of 40 cases]

Fourty patients with limited carpal fusion have been retrospectively reviewed. The aim of this study was to compare the results of four bone fusions (30 wrists) versus capitolunate fusion (11 wrists). Follow-up averaged 30 months with a range of 15-96 months. Twelve patients presented SLAC-wrist (scapho-lunate advanced collapse) and fourteen with SNAC-wrist (sapho-non union advanced collapse). There were seven cases of primitive wrist arthritis, one mid-carpal instability, one sequella of Fenton's syndrome, one Preiser's disease and two Kienbock's disease. All 40 patients were evaluated by the same observer. In terms of range of motion, the capito-lunate fusion led to better results than the four bone fusions with a gain of 10 degrees in volar flexion and 12 degrees in radial deviation. Results in term of post operative pain are similar in the two groups of patients with 90% painless wrist in four bone fusion and 81% with capito-lunate fusion. Results for strength were equivalent. Radiological bone fusion was obtained within nine weeks. Absence of fusion was observed in two patients with capito-lunate fusion. Our result in terms of joint motion and strength are similar to those found in the literature. Correction or not of the DISI deformity during the procedure did not affect the results (on 19 patients). The Four bone fusion procedure is still a good treatment in SLAC or SNAC wrist. Capito-lunate fusion remains a good choice, despite the risk of non-fusion.