Distal Tibial Allograft Augmentation for Posterior Shoulder Instability Associated With Glenoid Bony Deficiency: A Case Series

PURPOSE: To report the clinical history and preliminary outcomes of patients who underwent posterior glenoid reconstruction using a distal tibial allograft (DTA) for the management of posterior shoulder instability with glenoid bone loss. METHODS: Patients who underwent posterior shoulder stabilization with a DTA in our institution between 2011 and 2019 were retrospectively reviewed. Demographic characteristics, operative reports, and clinical and functional outcomes were recorded. Outcomes included postoperative range of motion (ROM), recurrent instability, complications, and revision surgery. All patients underwent at least 1 year of follow-up, except 2 patients who underwent revision surgery. Preoperative and postoperative ROM was compared using the 2-tailed Student t test for paired samples. RESULTS: Ten patients who underwent DTA augmentation for posterior instability were included, comprising 2 female and 8 male patients with an average age of 24 years (range, 17-35 years). Five patients had a prior sports-related traumatic event, and 2 patients had a seizure disorder. Seven patients had undergone a prior stabilization procedure. The average reverse bony Bankart lesion was 26% of the glenoid diameter. Concomitant procedures included 4 capsular repairs, 2 labral repairs, 2 capsular plications, and 1 repair for humeral avulsion of the glenohumeral ligament. One patient reported recurrent instability after surgery. Two patients underwent revision surgery, with one removal of symptomatic hardware and one early revision owing to screw penetration into the glenoid. There was no significant difference in preoperative versus postoperative ROM. CONCLUSIONS: Posterior shoulder instability with significant bony deficiency can be managed using DTA augmentation with good outcomes and a reasonable complication rate in these challenging cases. LEVEL OF EVIDENCE: Level IV, case series.