Glenohumeral morphological predictors of recurrent shoulder instability following arthroscopic Bankart repair

Abstract

Purpose: The purpose of this study was to evaluate glenohumeral morphological features on a magnetic resonance arthrogram (MRA) to determine risk factors for recurrence of anterior shoulder instability following arthroscopic Bankart repair (ABR).

Methods: A retrospective review of patients who underwent ABR between 2012 and 2017 was performed to identify patients who had recurrence of instability following stabilisation (Group 1). These were pair-matched in a 2:1 ratio for age, gender and sport with a control (Group 2) who underwent ABR without recurrence. Preoperative MRAs were evaluated for risk factors for recurrence, with glenoid bone loss and Hill-Sachs lesions also measured. Multilinear and multilogistic regression models were used to evaluate factors affecting recurrence.

Results: Overall, 72 patients were included in this study, including 48 patients without recurrence and 24 patients with recurrent instability. There was a significant difference between the two groups in mean glenoid bone loss (Group 1: 7.3% vs. Group 2: 5.7%, p < 0.0001) and the rate of off-track Hill-Sachs lesions (Group 1: 20.8% vs. Group 2: 0%, p = 0.0003). Of the variables analysed in logistic regression, increased glenoid anteversion (p = 0.02), acromioclavicular (AC) degeneration (p = 0.03) and increased Hill-Sachs width were associated with increased risk of failure. Increased chondral version (p = 0.01) and humeral head diameter in the anteriorposterior view were found to be protective and associated with a greater likelihood of success.

Conclusion: Glenoid anteversion was a risk factor for recurrent instability, whereas increased chondral version and humeral head diameter were associated with higher rates of success following ABR. Glenoid bone loss, presence of an off-track Hill-Sachs lesion, increased Hill-Sachs width and AC degeneration were also associated with failure. These findings should be used by surgeons to stratify risk for recurrence following ABR.

Level of evidence: Level III.

Keywords: Bankart repair; athlete; instability; recurrence; shoulder.