Arthroscopic Anatomic Glenoid Reconstruction Using Distal Tibial Allograft for Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes

Abstract

Background: The all-arthroscopic anatomic glenoid reconstruction technique using a distal tibial allograft avoids damage to the subscapularis muscle and allows repair of the capsulolabral tissue. Purpose: To analyze the clinicoradiologic outcomes of patients who underwent this procedure to treat anterior shoulder instability with glenoid bone loss with a minimum 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: Over 6 years, 73 patients (52 male and 21 female; mean age, 28.8 years) under the care of the same surgeon underwent arthroscopic stabilization with capsulolabral Bankart repair and bony allograft augmentation of the glenoid for recurrent shoulder instability with significant bone loss. Pre- and postoperative patient-reported functional assessment was performed using 2 questionnaires, the Western Ontario Shoulder Instability Index (WOSI) and the Disabilities of the Arm, Shoulder and Hand, and radiological assessment was performed using radiographs and computed tomography scans obtained preoperatively and approximately 1 year later (mean ± SD, 0.9 ± 1.1 years). Results: The mean follow-up was 4.7 ± 1.1 years. The mean pre- and postoperative WOSI scores were 71.1 ± 17.5 and 25.6 ± 21.9, respectively ( P < .001). There were no recurrences of dislocation, although 1 patient had symptoms of subluxation; however, 5 patients had hardware complications that required screw removal. There were no cases of nerve injury. Postoperative computed tomography scans were available for 66 patients. Seven patients were lost to follow-up. The graft union rate was 100%. Overall, graft resorption was <50% in 86% of patients (57/66). Eighteen patients (27%) had no resorption (grade 0), 39 (59%) had <50% (grades 1 and 2), and 9 (14%) had ≥50% (grade 3); however, none had symptoms of instability. The mean alpha angle of the screw between the screw shaft axis and the native glenoid axis was 18.3°± 5.7°. Graft positioning was flush with the glenoid in 61 of 66 patients (92.4%), and vertical positioning was excellent in 64 of 66 patients (97.0%) (3- to 5-o’clock position). Conclusion: Arthroscopic stabilization using distal tibial allograft augmentation resulted in excellent clinicoradiologic outcomes at a 2-year follow-up. This procedure has the advantages of being an anatomic reconstruction that addresses bony and soft tissue instability. However, long-term follow-up studies are necessary for better assessment of outcomes.