Clinical Outcomes of Revision Arthroscopic Capsulolabral Repair for Recurrent Anterior Shoulder Instability With Moderate Glenoid Bone Defects: A Comparison With Primary Surgery

BACKGROUND: The optimal revision surgery for failed primary arthroscopic capsulolabral repair (ACR) has yet to be determined. Revision ACR has shown promising results. PURPOSE: To compare the functional, strength, and radiological outcomes of revision ACR and primary ACR for anterior shoulder instability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between March 2007 and April 2017, a total of 85 patients underwent ACR (revision: n = 23; primary: n = 62). Functional outcome scores and positive apprehension signs were evaluated preoperatively, at 1 year, and then annually. Isokinetic internal and external rotation strengths were evaluated preoperatively and at 1 year after surgery. RESULTS: The mean follow-up was 36.5 ± 10.2 months (range, 24-105 months). There was no significant difference between the revision and primary groups in the glenoid bone defect size at the time of surgery (17.3% ± 4.8% vs 15.4% ± 5.1%, respectively; P = .197). At the final follow-up, no significant differences were found in the American Shoulder and Elbow Surgeons score (97.6 ± 3.1 vs 98.0 ± 6.2, respectively; P = .573), Western Ontario Shoulder Instability Index score (636.7 ± 278.1 vs 551.1 ± 305.4, respectively; P = .584), or patients with a positive apprehension sign (17.4% [4/23] vs 11.3% [7/62], respectively; P = .479) between the revision and primary groups. There was no significant difference between the revision and primary groups for returning to sports at the same preoperative level (65.2% vs 80.6%, respectively; P = .136) and anatomic healing failure at 1 year after surgery (13.0% vs 3.2%, respectively; P = .120). Both groups recovered external rotation strength at 1 year after surgery (vs before surgery), although the strength was weaker than in the uninvolved shoulder. In the revision group, a larger glenoid bone defect was significantly related to a positive apprehension sign (22.0% ± 3.8%) vs a negative apprehension sign (16.0% ± 3.2%; cutoff = 20.5%; P = .003). CONCLUSION: In patients with moderate glenoid bone defect sizes (10%-25%), clinical outcomes after revision ACR were comparable to those after primary ACR. However, significant glenoid bone loss was related to a positive remaining apprehension sign in the revision group. Surgeons should consider these findings when selecting their revision strategy for patients with failed anterior shoulder stabilization.