Surgical Stabilization for Recurrent Shoulder Instability Using Distal Tibial Allograft: Open Technique With Fresh Allograft Versus Arthroscopic Technique With Frozen Allograft, a Cohort Study

Abstract

BACKGROUND: The distal tibial allograft (DTA) procedure has been described as an effective treatment option for reconstruction of glenoid bone deficiency in the setting of recurrent anterior shoulder instability; however, no comparative data between an arthroscopic or open DTA approach are available. PURPOSE: To compare the clinical and radiographic outcomes of patients who underwent open fresh versus arthroscopic frozen DTA stabilization procedures. STUDY DESIGN: Cohort study; Level of evidence, 4. METHODS: A retrospective review was performed of consecutive patients with a minimum of 5% anterior glenoid bone loss (GBL) associated with recurrent anterior shoulder instability who underwent stabilization with either open fresh or arthroscopic frozen DTA glenoid reconstruction and had a minimum 2-year follow-up. Consecutive patients undergoing arthroscopic frozen DTA were matched in a 1-to-1 format to patients undergoing open fresh DTA by age, body mass index, and number of previous shoulder operations. Patients were evaluated postoperatively in terms of the Western Ontario Shoulder Instability Index (WOSI) score, pain relief, and episodes of recurrent instability. All patients also underwent postoperative imaging evaluation with computed tomography (CT) in which graft incorporation and allograft angle were measured. RESULTS: A total of 100 patients (50 open fresh DTA, 50 arthroscopic frozen DTA) with a median ± IQR age of 32.0 ± 6.7 and 27.9 ± 15.9 years, respectively, were analyzed at minimum 2-year follow-up. The open fresh DTA group had significantly more male patients than the arthroscopic frozen DTA group (98% vs 70%, respectively; P < .01), and patients in the open fresh DTA group had significantly greater GBL defects (25% ± 6% vs 21% ± 11%, respectively; P < .01). Both groups demonstrated significantly improved WOSI scores (P < .05) and had similar clinical outcomes regarding improvement postoperatively (P = .61), pain relief (P = .09), and recurrence rates (P = .31). Only 1 case of recurrent instability was noted, which occurred in the open fresh DTA cohort. Analysis of CT data at a mean of 15 months postoperatively showed no significant difference between open fresh versus arthroscopic frozen DTA groups. CONCLUSION: Open fresh and arthroscopic frozen DTA for anatomic glenoid reconstruction in patients with recurrent anterior shoulder instability resulted in a clinically stable joint with comparable outcomes and excellent healing rates. Additional long-term studies are needed to determine whether the surgical technique and type of allograft used influence clinical outcomes and whether these results are maintained over time.