Failure Analysis in Patients With Recurrent Anterior Shoulder Instability After Primary Arthroscopic Capsulolabral Repair

Background: Failure after primary arthroscopic capsulolabral repair for anterior shoulder instability is often multifactorial. Although several patient-related, bony morphologic, and surgical factors have been associated with recurrent instability, their coexistence in patients undergoing revision surgery remains incompletely characterized. Purpose: To describe the prevalence and coexistence of previously reported patient-related, bony morphologic, and anchor-related known risk factors for recurrence in patients undergoing revision surgery after failed primary arthroscopic capsulolabral repair using multiplanar reconstruction (MPR)–corrected computed tomography (CT) scans. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Consecutive patients who underwent revision surgery for recurrent anterior shoulder instability after primary arthroscopic capsulolabral repair between 2013 and 2021 and had CT scans suitable for MPR were included. Patients who underwent additional stabilization procedures at the index surgery were excluded. MPR-corrected CT scans were assessed for glenoid bone loss, Hill-Sachs morphology and glenoid track status, intact anterior articular arc angle, glenoid version, glenoid concavity, bony shoulder stability ratio, and anchor-related factors. The prevalence and coexistence of predefined known risk factors for recurrence were analyzed descriptively. Results: A total of 55 patients were included, 89% of whom were male, with a median age of 27 years. At the time of index surgery, 32% were <20 years of age, and hyperlaxity was present in 47%. The median number of predefined known risk factors for recurrence per patient was 6, and 85% of patients had ≥4. Hill-Sachs lesions were present in 94% of patients, including off-track lesions in 41%. Intact anterior articular arc angle <150° was present in 85%, glenoid concavity depth ≤2 mm in 78%, glenoid retroversion <4° in 57%, and glenoid bone loss >15% in 45%. Anchor-related abnormalities included peri-implant osteolysis in 53%, use of <3 anchors in 43%, absence of an anchor at the 5:30 position in 41%, extra-anatomical anchor placement in 40%, and anchor coverage <90° in 40%. Conclusion: Failed primary arthroscopic capsulolabral repair was associated with multiple coexisting known risk factors for recurrence. Although descriptive rather than causal, these findings support a comprehensive prerevision assessment for recurrence risk factors, including MPR-corrected CT to evaluate bipolar bone loss, glenoid morphology, Hill-Sachs engagement, and anchor placement before revision surgery.