Arthroscopic Bankart repair: results and risk factors of recurrence of instability.

The purpose of this study was to discover the recurrence rate of instability after arthroscopic Bankart repair and to assess risk factors for recurrence, with special interest in bone defects seen on preoperative plain radiographs. Consecutive unselected patients (182; 186 shoulders) with recurrent instability (redislocation or subluxation) after initial traumatic anteroinferior shoulder dislocation were operated on using arthroscopic suture-anchor repair at our institution during 2000-2005. Demographic data and details of the operation were retrospectively reviewed from case records, and glenoid and Hill-Sachs lesions were assessed from preoperative radiographs. The primary outcome measure was recurrence of instability (redislocation or subluxation). Functional results were assessed via Oxford instability scores and subjective shoulder values (SSVs), using postal questionnaires. One hundred and seventy-four shoulders (170 patients) were assessed after a median of 51 (range 24-95) months' follow-up. The recurrence rate of instability was 19% (redislocation 9% and subluxation 10%). Eighteen patients (10%) needed further surgery. The mean Oxford instability score was 21 and the mean SSV 84%. The recurrence rate among patients aged 20 or less was 44% and among patients over 20, 12%. Multivariate logistic regression analysis showed that age ≤20 (OR 8.8), Hill-Sachs lesion (OR 3.3), glenoid erosion (OR 2.7) and length of follow-up (OR 1.5) were the most important risk factors for recurrence. Young age is the most important risk factor for recurrence of instability after arthroscopic suture-anchor Bankart repair. Bone defects seen in preoperative plain radiographs are less important and more accurate imaging is needed to reveal their true role for recurrence of instability.