Bone formation of the coracoid bone graft after the Bristow procedure assessed using three-dimensional computed tomography.

ABSTRACT

BACKGROUND: The Bristow procedure has been shown to be a reliable method to prevent recurrent anterior shoulder instability by compensating for glenoid bone loss and producing the sling effect. The degree of postoperative morphological change in the coracoid bone graft is speculated to influence glenohumeral joint stability; however, the details of these changes after the Bristow procedure remain unknown. This study was performed to quantify the postoperative change in the coracoid bone graft volume as assessed by three-dimensional computed tomography (3D-CT). METHODS: The Bristow procedure was performed on 17 shoulders in 17 patients from August 2018 to January 2020. All patients were men, and their mean age at surgery was 17.9 years. The mean follow-up duration was 21.4 months. Within the first week after the operation (Time 0) and at the final follow-up, 3D-CT was used to determine the total coracoid bone graft volume. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) shoulder score, the University of California Los Angeles (UCLA) shoulder score, and the Western Ontario Shoulder Instability Index (WOSI). RESULTS: The mean volume of the total coracoid bone graft was 1.26 ± 0.29 cm3 at Time 0 and 1.90 ± 0.36 cm3 at the final follow-up (p < 0.0001). The mean JOA score, UCLA score, and WOSI were significantly better at the final follow-up than preoperatively (p < 0.001). No postoperative infection, neurovascular injury, or recurrent instability of the glenohumeral joint occurred. CONCLUSIONS: In the Bristow procedure, the volume of the total coracoid bone graft as shown by 3D-CT was significantly greater at the final follow-up than at Time 0, and bone formation of the coracoid bone graft was found after the Bristow procedure.