Anterior mid-portion capsular tear with Bankart lesion in recurrent anterior shoulder dislocation: outcome report and bone defect evaluation

Arthroscopic posterior capsulolabral repair grants adequate outcomes in shoulders with posterior instability without glenoid cartilage lesions

INTRODUCTION

Posterior capsulolabral repair (posterior Bankart) is effective to restore shoulder stability and relieve pain, though a recent meta-analysis reported recurrent instability in 9.5% of patients, and that only 62.7% were able to resume sports. The purpose of this study was to assess the outcomes of arthroscopic posterior capsulolabral repair in a population of unselected patients, in terms of recurrence of instability, clinical scores, and return to sports.

METHODS

The authors retrospectively studied a consecutive series of 22 patients that underwent posterior capsulolabral repair between 2009 and 2019. Patients were assessed before posterior capsulolabral repair and at a minimum follow-up of 24 months, in terms of subjective shoulder value (SSV), Western Ontario Shoulder Instability Index (WOSI), as well as level of sport. Following surgery, all complications, reoperations or episodes of instability were noted.

RESULTS

The cohort comprised 21 men (95%) and 1 woman (5%), aged 38.8 ± 12.5 years (range 17-61) at index surgery. Of the 20 patients that performed sports, only 2 (10%) stopped sports after surgery, while 18 resumed their main sport (90%). At a follow-up of 65.4 ± 34.8 months (range 25-146), the SSV was 85.1 ± 14.7, pain on VAS was 1.9 ± 2.1, and the Constant-Murley score was 71.6 ± 17.9. Five patients had subjective instability without dislocation (23%). Nine patients (41%) had no pain (0 points), 6 patients (27%) had mild pain (1-2 points), 4 patients (18%) had moderate pain (3 points), while 3 patients (14%) had severe pain (5-8 points).

CONCLUSION

Arthroscopic posterior capsulolabral repair prevented recurrent dislocation in patients with posterior shoulder instability at a minimum follow-up of 2 years, despite persistent pain in 32%, and subjective instability in 23%. These complications were mainly observed in patients with work-related accidents and glenoid cartilage lesions.

LEVEL OF EVIDENCE

III, case series.

Increased superior translation following multiple simulated anterior dislocations of the shoulder

PURPOSE

Recurrent shoulder dislocations can result in kinematic changes of the glenohumeral joint. The number of prior shoulder dislocations may contribute to increased severity of capsulolabral lesions. The kinematics of the glenohumeral joint following multiple dislocations remain poorly understood. The purpose of this study was to assess the kinematics of the glenohumeral joint during anterior dislocations of the shoulder, and more specifically, altered translational motion following multiple dislocations. The kinematics of the glenohumeral joint were hypothesized to change and correlate with the number of dislocations.

METHODS

Eight fresh-frozen cadaveric shoulders were dissected free of all soft tissues except the glenohumeral capsule. Each joint was mounted in a robotic testing system. At 60 degrees of glenohumeral abduction, an internal and external rotational torque (1.1 Nm) were applied to the humerus, and the resulting joint kinematics were recorded. Anterior forces were applied to the humerus to anteriorly dislocate the shoulder and the resulting kinematics were recorded during each dislocation. Following each dislocation, the same rotational torque was applied to the humerus, and the resulting joint kinematics were also recorded. A repeated-measures analysis of variance (ANOVA) was used to compare the kinematics following each dislocation.

RESULTS

During the 7th, 8th, 9th, and 10th dislocations, the humerus significantly translated superiorly compared with the shoulder during the 1st dislocation (p < 0.05). Following the 3rd, 4th, 5th, and 10th dislocations, the humeral head significantly translated superiorly compared with the shoulder following the 1st dislocation in the position of 60 degrees of abduction in response to external rotation torque (p < 0.05).

CONCLUSION

Multiple anterior shoulder dislocations lead to abnormal translational kinematics and result in increased superior translation of the humerus. This may contribute to pathologic superior extension of capsulolabral injuries. Superior translation of the humerus with overhead motion in the setting of recurrent instability may also place the shoulder at risk for extension of the capsulolabral injuries.