Clinical and Radiological Outcomes of Scaphocapitate Fusion in Kienböck Disease: A Systematic Review and Meta-Analysis.

Purpose: To report the functional and radiological outcomes of scaphocapitate (SC) arthrodesis in the treatment of Kienböck disease. Methods: This meta-analysis was conducted with adherence to PRISMA guidelines. Google Scholar, PubMed, Cochrane and Virtual Health Library were searched from inception until November 2022. All original studies that investigated the outcomes of scaphocapitate fusion in Kienböck disease were included. Exclusion criteria were arthroscopically performed fusions, concomitant radial shortening, traumatic or other etiologies of lunate avascular necrosis, and studies published in languages other than English. Outcomes of interest were pre- and post-operative wrist range of motion, VAS score, functional scores, radiological outcomes, surgical technique, complication rate and reoperation rate. Results: The total number of included participants was 203 from 11 articles. The results showed no significant differences pre- and post-operatively in terms of wrist flexion, extension and ulnar deviation. However, there was a significant reduction in radial deviation after the surgery (WMD -2.30; 95% CI, -4.26 to -0.33). Moreover, a significant increase was noticed in grip strength in Kg (WMD 13.29; 95% CI, 3.21-23.37) and mmHg post-operatively (WMD 23.75; 95% CI, 17.56-29.94). In addition, the models demonstrated significant decrease in carpal height (WMD -0.01; 95% CI, -0.02 to 0.00), scapholunate angle (WMD -12.11; 95% CI, -20.46 to -3.77) and radioscaphoid angle after the surgery (WMD -12.09; 95% CI, -15.51 to -8.67). The pooled overall rate of complication and reoperation rates were 24% (95% CI, 6%-47%) and 14% (95% CI, 3%-31%), respectively. Conclusions: Scaphocapitate arthrodesis is an effective procedure for treatment of Kienböck disease. This procedure is associated with satisfactory functional outcomes and significant improvement in pain scores and grip strength. Further studies with larger sample sizes and reduced heterogeneity are needed for a better evaluation of the results. Clinical relevance: Scaphocapitate arthrodesis is a recommended surgery for Kienböck disease with satisfactory functional and radiological outcomes. However, patients should be counseled on the possible complications and reoperation rate.