Arthroscopic Bankart repair and capsular shift for recurrent anterior shoulder instability: functional outcomes and identification of risk factors for recurrence.

BACKGROUND: Arthroscopic Bankart repair and capsular shift is a well-established technique for the treatment of anterior shoulder instability. The purpose of this study was to evaluate the outcomes following arthroscopic Bankart repair and capsular shift and to identify risk factors that are predictive of recurrence of glenohumeral instability.
METHODS: We performed a retrospective review of a prospectively collected database consisting of 302 patients who had undergone arthroscopic Bankart repair and capsular shift for the treatment of recurrent anterior glenohumeral instability. The prevalence of patient and injury-related risk factors for recurrence was assessed. Cox proportional hazards models were used to estimate the predicted probability of recurrence within two years. The chief outcome measures were the risk of recurrence and the two-year functional outcomes assessed with the Western Ontario shoulder instability index (WOSI) and disabilities of the arm, shoulder and hand (DASH) scores.
RESULTS: The rate of recurrent glenohumeral instability after arthroscopic Bankart repair and capsular shift was 13.2%. The median time to recurrence was twelve months, and this complication developed within one year in 55% of these patients. The risk of recurrence was independently predicted by the patient's age at surgery, the severity of glenoid bone loss, and the presence of an engaging Hill-Sachs lesion (all p < 0.001). These variables were incorporated into a model to provide an estimate of the risk of recurrence after surgery. Varying the cutoff level for the predicted probability of recurrence in the model from 50% to lower values increased the sensitivity of the model to detect recurrences but decreased the positive predictive value of the model to correctly predict failed repairs. There was a significant improvement in the mean WOSI and DASH scores at two years postoperatively (both p < 0.001), but the mean scores in the group with recurrence were significantly lower than those in the group without recurrence (both p < 0.001).
CONCLUSIONS: Our study identified factors that are independently associated with a higher risk of recurrence following arthroscopic Bankart repair and capsular shift. These data can be useful for counseling patients undergoing this procedure for the treatment of recurrent glenohumeral instability and individualizing treatment options for particular groups of patients. LEVEL OF EVIDENCE: Prognostic level I. See Instructions for authors for a complete description of levels of evidence.