Summary

After arthroscopic Bony Bankart repair using the double row technique, all 47 shoulders had bony union of the bone fragments and an improvement in the glenoid defect from a mean of 15.2% to 5.4%. However, in three patients who returned to collision sports at 6 months, the bone fragments re-fractured and recurred.

Abstract

Background; A high recurrence rate has been reported in patients with Bankart lesion with a glenoid defect after simple arthroscopic Bankart repair. On the other hand, in bony Bankart lesions, fixation of the ligament together with the bone fragments is expected to result in bony union and a reduction in the glenoid defect. However, in some cases there is nonunion or the bone fragments are so small that the bone defect is still large after bone union. Arthroscopic Bankart repair using the double row technique (Yoneda, 2014) is expected to result in good bone healing and remodeling of the glenoid fossa, but the bone union rate and reduction of glenoid defect still is not clear. The purpose of this study was to determine the bone union rate, reduction in the size of the glenoid defect and postoperative outcome after arthroscopic Bankart repair using the double row technique for patients with traumatic anterior shoulder instability.
Patients & Methods; Subjects were 135 patients with 139 shoulders who underwent arthroscopic Bankart repair using the double row technique from August 2014 to July 2023. Of these, 47 shoulders had Bankart lesions with bone fragments, age at surgery 23 years (14-47), 45 males and 2 females. Bone union determination was possible in 36 shoulders at 6 months postoperative CT, and 28 shoulders could be followed up for more than 2 years. After dissection of the bony fragment and inferior glenohumeral ligament, three or four all suture anchors were driven into the anterior neck of the scapular, and the sutures were passed under the bone fragments to the ligament. The sutures were then threaded with three or four GRYPHONE BR anchors, two through each, and driven into the anchor holes created in the anterior margin of the glenoid fossa. Postoperatively, the patient was immobilised for 4 weeks. Return to sports was permitted at 6 months. 3D CT was taken preoperatively, at 1 week, 6 months and 2 years postoperatively, and the rate of glenoid bone loss was assessed using the circular approximation method that was previously reported. Bone fragment size was defined as 5%>S, 5-10%; M, 10%<L of the glenoid diameter according to Nakagawa's criteria.
Results; CT at 6-month postoperatively showed bone union in all 36 shoulders; the mean glenoid defect rate in the 28 shoulders that were followed up for more than 2 years improved significantly from 15.2% (3.5-29.9) preoperatively to 5.4% (0-17.7) postoperatively. Bone defects relative to fragment size improved on average by S: 4.3%, M: 7.8% and L: 19.5%. The postoperative outcome improved from 36 (15-50) preoperative Rowe score to 91 (25-100) postoperatively; three patients had postoperative recurrences, all of which were re-injured 1 or 2 months after return to collision sports, and the bone fragments were re-fractured.
Conclusions; Arthroscopic Bankart repair using the double row technique can be expected to ensure bony union, but the bone fragments are not strong enough for a 6-month return to collision sports and there might be a risk of recurrence.