Arthroscopic Bone Xenograft Augmentation for Glenoid Bone Deficiency and Recurrent Anterior Shoulder Instability Improves Functional Outcomes Despite Graft Nonunion

Purpose To analyze the healing of equine‐derived xenograft bone blocks with the native glenoid using computed tomography (CT) and to evaluate clinical outcomes in patients undergoing arthroscopic bone block stabilization with xenograft, Bankart repair, and upper‐third subscapularis tenodesis for recurrent anterior shoulder instability with glenoid bone loss. Methods Patients with recurrent anterior shoulder instability and glenoid bone loss between 12.5% and 25% who underwent arthroscopic equine‐derived xenograft bone block augmentation combined with Bankart repair and upper‐third subscapularis tenodesis between 2019 and 2023 were identified. Minimum clinical and radiological follow‐up was 24 months. Xenograft healing was evaluated on serial CT scans, and clinical outcomes were assessed using Western Ontario Shoulder Instability Index, Rowe, quick Disabilities of the Arm, Shoulder and Hand, and visual analog scale scores. Results A total of 76 patients (72 men, 4 women) met the inclusion criteria and were analyzed, with a mean clinical follow‐up of 50.7 months (range, 24‐75 months). Radiological follow‐up on CT averaged 46.1 months (range, 24‐72 months). All patients underwent CT imaging according to the study protocol. Western Ontario Shoulder Instability Index improved from 1335.7 ± 136.8 to 134.6 ± 138.2 ( P < .001), with 100% of patients exceeding the minimal clinically important difference (MCID) threshold; Rowe scores increased from 35.3 ± 12.2 to 90.8 ± 11.0 ( P < .001), with 100% surpassing the MCID; mean quick Disabilities of the Arm, Shoulder and Hand improved from 42.6 ± 21.2 to 4.0 ± 4.7 ( P < .001), with 86.8% exceeding the MCID; and visual analog scale decreased from 1.3 ± 1.1 to 0.5 ± 1.1 ( P < .001), with 72.4% of patients reaching the MCID. Recurrence occurred in 4 patients (5.3%) because of high‐energy trauma, and 2 patients presented Samilson‐Prieto grade III osteoarthritis. Despite no radiographic graft‐glenoid fusion being observed in any patient (0/76), graft morphology and volume were maintained without signs of resorption throughout follow‐up. Conclusions Despite the lack of radiographic union, most patients treated with arthroscopic bone xenograft plus Bankart repair and upper‐third subscapularis tenodesis showed functional improvements surpassing the MCID threshold at a minimum 2‐year follow‐up. Level of Evidence Level IV, retrospective therapeutic case series.