Restoration of the Posterior Glenoid in Recurrent Posterior Shoulder Instability Using an Arthroscopically Placed Iliac Crest Bone Graft: A Computed Tomography–Based Analysis

Abstract

Background: Posterior shoulder instability is uncommon, and its treatment is a challenging problem. An arthroscopically assisted technique for posterior iliac crest bone grafting (ICBG) has shown promising short- and long-term clinical results. Changes as shown on imaging scans after posterior ICBG for posterior shoulder instability have not been investigated in the recent literature. Purpose: To evaluate changes on computed tomography (CT) after arthroscopically assisted posterior ICBG and to assess clinical outcomes. Study Design: Case series; Level of evidence, 4. Methods: Patients with preoperative CT scans and at least 2 postoperative CT scans with a minimum follow-up of 2 years were included in the evaluation. Of 49 initial patients, 17 (follow-up rate, 35%) met the inclusion criteria and were available for follow-up. We measured the glenoid version angle and the glenohumeral and scapulohumeral indices on the preoperative CT scans and compared them with measurements on the postoperative CT scans. Postoperatively, graft surface, resorption, and defect coverage were measured and compared with those at early follow-up (within 16 months) and final follow-up (mean ± SD, 6.6 ± 2.8 years). Results: The mean preoperative glenoid version was –17° ± 13.5°, which was corrected to –9.9° ± 11.9° at final follow-up (P