Arthroscopic Bankart repair with an individualized capsular shift restores physiological capsular volume in patients with anterior shoulder instability

PURPOSE: Capsular volume reduction in the context of anterior arthroscopic shoulder stabilization represents an important but uncontrolled parameter. The aim of this study was to analyse capsular volume reduction by arthroscopic Bankart repair with an individualized capsular shift in patients with and without ligamentous hyperlaxity compared to a control group. METHODS: In the context of a prospective controlled study, intraoperative capsular volume measurements were performed in 32 patients with anterior shoulder instability before and after arthroscopic Bankart repair with an individualized capsular shift. The results were compared to those of a control group of 50 patients without instability. Physiological shoulder joint volumes were calculated and correlated with biometric parameters (sex, age, height, weight and BMI). RESULTS: Patients with anterior shoulder instability showed a mean preinterventional capsular volume of 35.6 ± 10.6 mL, which was found to be significantly reduced to 19.3 ± 5.4 mL following arthroscopic Bankart repair with an individualized capsular shift (relative capsular volume reduction: 45.9 ± 21.9%; P < 0.01). Pre-interventional volumes were significantly greater in hyperlax than in non-hyperlax patients, while post-interventional volumes did not differ significantly. The average shoulder joint volume of the control group was 21.1 ± 7.0 mL, which was significantly correlated with sex, height and weight (P < 0.01). Postinterventional capsular volumes did not significantly differ from those of the controls (n.s.). CONCLUSION: Arthroscopic Bankart repair with an individualized capsular shift enabled the restoration of physiological capsular volume conditions in hyperlax and non-hyperlax patients with anterior shoulder instability. Current findings allow for individual adjustment and intraoperative control of capsular volume reduction to avoid over- or under correction of the shoulder joint volume. Future clinical studies should evaluate, whether individualized approaches to arthroscopic shoulder stabilization are associated with superior clinical outcome.