Follow-up Computed Tomography Arthrographic Evaluation of Bony Bankart Lesions After Arthroscopic Repair

Purpose: The follow-up results of bony union after an arthroscopic bony Bankart repair have not been reported. We studied follow-up computed tomography (CT) arthrograms to evaluate radiographic healing of bony Bankart fragments. Methods: Among 41 patients who underwent arthroscopy for a bony Bankart lesion between July 2006 and May 2009, 31 cases in 30 patients who had undergone sequential follow-up CT arthrography preoperatively, at 3 months postoperatively, and at 1 year postoperatively were enrolled. Radiologic patterns of fracture healing were classified into bony healing and fibrous healing. The mean age was 23.4 years, and the mean follow-up was 30.5 months. The mean interval from the first trauma to surgery was 32.5 months, and the mean preoperative dislocation number was 12.1. Results: The mean preoperative glenoid defect was 14.1%. The fracture healing patterns included 26 bony and 5 fibrous unions. There was a significant positive relation between the total dislocation number and the preoperative glenoid defect (P = .003). The proportion of the mean fragment dimension to a circle drawn through the outer cortex of the inferior glenoid was 8.4% preoperatively, 6.6% at 3 months postoperatively, and 6.2% at 1 year postoperatively. The fragment size decreased from that measured preoperatively to the size measured 3 months after surgery (P < .05). However, the fragment size was maintained between 3 months and 1 year postoperatively (P > .05). The mean Rowe score at 1 year postoperatively was 97.2. Conclusions: Follow-up CT arthrographic evaluation showed that small bony Bankart fragments survived without resorption until 1 year postoperatively, even with fibrous union, and that reattached bone fragment fixation to the anatomic position with the labrum could survive. Level of Evidence: Level IV, therapeutic case series.