Three-Dimensional Computed Tomography-based Analysis of Joint Contact Area Changes After Capitate Shortening Osteotomy in Kienböck Disease: A Retrospective Case Series

Background: To evaluate changes in wrist joint contact after capitate-shortening osteotomy for Kienböck disease using in-vivo three-dimensional (3D) computed tomography-based bone models. Methods: In a multicenter retrospective case series, six wrists of six patients undergoing isolated capitate-shortening osteotomy for Kienböck disease were analyzed. Pre- and postoperative CT datasets were reconstructed into patient-specific bone models. Contact areas between the radius and carpal bones and among intercarpal joints were quantified, and contact-centroid locations were computed to evaluate the spatial redistribution of load. The primary outcomes were radiolunate, radioscaphoid, and lunocapitate contact areas, and the secondary outcomes were centroid shifts indicating the direction of load transfer. Results: Six patients were classified as Lichtman stage II (3 wrists), IIIA (2 wrists), and IIIB (1 wrist); all showed significant improvements in VAS and MMWS during follow-up. Postoperatively, radiolunate and lunocapitate contact areas decreased, whereas the radioscaphoid contact area increased; these changes were statistically significant. The centroid analysis revealed a dorsoradial shift at the radioscaphoid region and a palmar shift at the lunocapitate region. Conclusions: Capitate-shortening osteotomy was associated with decreased radiolunate and lunocapitate contact areas and increased radioscaphoid contact area on three-dimensional CT-based models. These findings support the rationale for capitate shortening as a procedure that influences wrist joint contact patterns in Kienböck disease and provide objective imaging metrics that may aid postoperative evaluation and future comparative studies. Clinical trial number:Not applicable.