Recurrent shoulder dislocation often occurs due to the lack of timely treatment after the initial dislocation caused by trauma or violent sports activities. Although the glenohumeral joint is reduced, the structures maintaining shoulder joint stability remain unrepaired, such as glenoid bone defects and labral injuries. Subsequent trauma or improper movement patterns may lead to recurrent shoulder dislocation. In recent years, with the advancement of arthroscopic techniques, various surgical approaches have been developed to treat recurrent shoulder dislocation. The most common procedures include soft tissue repair, represented by Bankart repair, and bone repair, represented by Latarjet surgery. Previous studies have indicated that the failure rate of surgery, primarily attributed to significant bone defects, reaches 67%. It has been demonstrated that when glenoid bone defects exceed 20%, bone repair surgery can achieve better shoulder joint stability. For patients with high demands for physical activity, a subcritical bone defect threshold of 13.5% has been proposed, suggesting Latarjet surgery or combined procedures for defects exceeding this threshold. However, controversy remains regarding the surgical treatment of bone defects of varying degrees. Patients with glenoid bone defects ranging from 13.5% to 20% may face the risk of "over-treatment" with Latarjet techniques, while Bankart repair alone may result in a higher redislocation rate.

To explore the preliminary clinical efficacy of arthroscopic subscapularis augmentation with the long head of the biceps tendon for anterior shoulder instability (ASA-LHBT) in the treatment of recurrent shoulder dislocation in the treatment of glenoid bone defects ranging from 13.5% to 20% in recurrent shoulder dislocation.

A retrospective study was conducted on 25 patients with recurrent shoulder dislocation and glenoid bone defects ranging from 13.5% to 20%, treated with arthroscopic long head of biceps tendon transposition with subscapularis muscle reinforcement technique from June 2020 to June 2021. Visual analogue scale (VAS), Rowe score, American shoulder and elbow surgeons (ASES) rating scale, and active range of motion of the affected shoulder joint were evaluated.

During the postoperative follow-up period, there were no recurrent dislocations. The VAS pain score of the patients (0.52±0.65) points decreased compared to preoperative scores (2.88±1.01) points. The Rowe score and ASES score showed significant improvements (93.60±3.69) points and (94.93±3.42) points, respectively compared to preoperative scores (50.60±9.39) points and (65.93±5.38) points, respectively, with statistically significant differences in clinical scores. The comparison of pre-and postoperative internal rotation active range of motion of the shoulder joint showed statistically significant differences (P<0.05), and there were significant correlations in forward flexion, abduction, lateral rotation, and 90° abduction external rotation angles between preoperative and 2-year postoperative periods (P<0.05) .

Arthroscopic long head of biceps tendon transposition with subscapularis muscle reinforcement technique is effective in treating glenoid bone defects ranging from 13.5% to 20%.