Long-term outcomes of three-corner fusion versus four-corner fusion in the treatment of SLAC and SNAC wrist stage 3: a single-center retrospective study with a median follow-up of 7 years.

PURPOSE: Partial wrist arthrodesis is currently the gold standard for advanced wrist arthritis secondary to SLAC or SNAC wrist stage 3. Three-corner fusion (3-CF) and four-corner fusion (4-CF) are two available options, but no study has directly compared them with sufficient follow-up in a homogeneous population. METHODS: This is a single-center retrospective study comparing the long-term functional outcomes of 3-CF and 4-CF. The primary endpoint was the PRWE score. The following were also collected: QuickDASH score, MAYO wrist score, range of motion, grip strength, pain, satisfaction, non-union rate, secondary osteoarthritis, complications, and revision surgery. RESULTS: Thirty-four patients with SLAC or SNAC wrist stage 3, including 16 3-CF and 18 4-CF, were evaluated, with an overall median follow-up of 86 (53; 139) months. No significant difference was found for adjusted PRWE (47.3 (95% CI 14.7; 75.4) in the 3-CF group and 70.7 (95% CI 49.7; 100.1) in the 4-CF group (p = 0.11)) nor for the adjusted QuickDASH score (30.1 (95% CI 7.9; 52.1) in the 3-CF group and 54.4 (95% CI 36.3; 68.1) in the 4-CF group (p = 0.11)). Complication and revision rates were comparable. CONCLUSION: Both techniques provide similar functional outcomes. The results are consistent with the concept that limited midcarpal fusion may represent a valid alternative in stage 3 SLAC/SNAC wrist surgery. Level of Evidence IV, retrospective cohort study.