CT-based evaluation of bony Bankart lesions after arthroscopic Trillat stabilization for anterior shoulder instability.

Abstract

Purpose: Bony Bankart lesions are known to contribute to anterior shoulder instability, and their evolution has mainly been studied after arthroscopic repair. However, the evolution of these lesions after shoulder stabilization without any specific procedure performed on the osseous fragment remains unknown. The aim of this study was to assess the CT-based evolution of bony Bankart lesions after arthroscopic Trillat stabilization.

Methods: This retrospective, single-center study included patients treated between 2013 and 2022 for chronic anterior shoulder instability with a bony Bankart lesion who underwent arthroscopic Trillat stabilization. Glenoid bone loss and fragment characteristics were assessed on CT scans by two independent observers using the best-fit circle method. Fragment size, position, consolidation, and resorption were also evaluated. Postoperative CT scans were used to assess changes in consolidation and resorption over time.

Results: Twenty-eight patients were included. The mean glenoid defect size was 10.3%. The proportion of patients with complete union increased significantly from 21.4% preoperatively to 85.7% postoperatively (p < 0.01). Fragment resorption increased from 27.1% preoperatively to 40.1% postoperatively (p < 0.001). A non-significant inferior shift in fragment position was observed postoperatively. An association was observed between preoperative consolidation and the time since the last dislocation. An association was also observed between the absence of postoperative consolidation and postoperative recurrence.

Conclusion: CT-based evaluation of bony Bankart lesions after arthroscopic Trillat surgery demonstrated fragment consolidation and resorption at 6 months postoperatively, without any significant change in fragment position or glenoid defect size.

Level of evidence: Level IV, Retrospective case series.