Four-corner fusion: comparison of patient satisfaction and functional outcome of conventional K-wire technique vs. a new locking plate

Four-corner fusion is a standard procedure for advanced carpal collapse. Several operative techniques and numerous implants for osseous fixation have been described. Recently, a specially designed locking plate (Aptus©, Medartis, Basel, Switzerland) was introduced. The purpose of this study was to compare functional results after osseous fixation using K-wires (standard of care, SOC) with four-corner fusion and locking plate fixation.

21 patients who underwent four-corner fusion in our institution between 2008 and 2013 were included in a retrospective analysis. In 11 patients, osseous fixation was performed using locking plates whereas ten patients underwent bone fixation with conventional K-wires. Outcome parameters were functional outcome, osseous consolidation, patient satisfaction (DASH- and Krimmer Score), pain and perioperative morbidity and the time until patients returned to daily work. Patients were divided in two groups and paired t-tests were performed for statistical analysis.

No implant related complications were observed. Osseous consolidation was achieved in all cases. Differences between groups were not significant regarding active range of motion (AROM), pain and function. Overall patient satisfaction was acceptable in all cases; differences in the DASH questionnaire and the Krimmer questionnaire were not significant. One patient of the plate group required conversion to total wrist arthrodesis without implant-related complications.

Both techniques for four-corner fusion have similar healing rates. Using the more expensive locking implant avoids a second operation for K-wire removal, but no statistical differences were detected in functional outcome as well as in patient satisfaction when compared to SOC.