summary A posterior labral tear is referred to as a reverse Bankart lesion, or attenuation of the posterior capsulolabral complex, and commonly occurs due to repetitive microtrauma in athletes. Diagnosis can be made clinically with positive posterior labral provocative tests and confirmed with MRI studies of the shoulder. Treatment may be nonoperative or operative depending on chronicity of symptoms, degree of instability, and patient activity demands. Epidemiology Demographics athletes weightlifters (bench press) football linemen (blocking) swimmers gymnasts wrestlers Etiology Pathophysiology repetitive microtrauma to the posterior capsulolabral complex most common mechanism posteriorly directed force with the arm in a flexed, internally rotated and adducted position glenoid retroversion patients with increased glenoid retroversion (~17°) were 6x more likely to experience posterior instability compared to those with less glenoid retroversion (~7°) Associated injuries Kim lesion an incomplete and sometimes concealed avulsion of posteroinferior labrum Anatomy Posterior labrum function helps generate cavity-compression effect of glenohumeral joint creates 50% of the glenoid socket depth provides posterior stability anatomy composed of fibrocartilagenous tissue anchors posterior inferior glenohumeral ligament (PIGHL) Glenohumeral joint anatomy Presentation Symptoms vague, nonspecific posterior shoulder pain is the most common symptoms worsens with provocative activities that apply a posteriorly directed force to the shoulder ex: pushing heavy doors, bench press, push-ups clicking or popping in the shoulder with range of motion sense of instability less common pain during throwing late cocking phase Physical exam posterior joint line tenderness provocative tests posterior apprehension test arm positioned with shoulder forward flexed 90° and adducted apply anterior support to scapula apply posteriorly directed force to shoulder through humerus positive if patient experiences sense of instability or pain posterior load and shift test patient rests arm at their side grasp the proximal humerus and apply a posteriorly directed force assess distance of translation and patient response grade 0 = no translation grade 1 = to edge of glenoid grade 2 = over edge of glenoid but spontaneously relocates grade 3 = over edge of glenoid, does not spontaneously relocate jerk test arm positioned with shoulder abducted 90° and fully internally rotated axially load humerus while adducting the arm across the body clunk indicates subluxation of the humeral head off the posterior glenoid highly sensitive and specific for a posterior labral tear kim test arm positioned with shoulder abducted 90° and forward flexed 45° apply posteriorly and inferiorly directed force to shoulder through humerus positive if patient experiences pain highly sensitive and specific for posteroinferior labral tear Imaging Radiographs recommended views true AP, scapular Y and axillary views axillary view required to ensure glenohumeral joint reduction posterior shoulder dislocations may be missed on AP radiographs alone findings often normal in chronic cases axillary view may show glenoid retroversion or posterior glenoid erosion MRI indications diagnostic study of choice technique intra-articular contrast increases sensitivity for labral pathology Treatment Nonoperative activity modification, NSAIDs, PT indications first line of treatment technique rotator cuff and deltoid strengthening periscapular stabilization Operative posterior labral repair, capsulorrhaphy indications extensive nonoperative management fails technique arthroscopic and open techniques may be used arthroscopic preferred to open given the extensive posterior surgical dissection required more reliable return to play suture anchor repair and capsulorrhaphy results in fewer recurrences and revisions than non-anchored repairs probing of posterior labrum is required to rule out a subtle Kim lesion outcomes generally good return to previous level of function in overhead throwing athletes not as reproducible as other athletes failure risk increases if adduction and internal rotation are not avoided in the acute postoperative period increased risk of recurrence if posterior bone loss is not addressed concurrently recent studies show 11% glenoid bone loss resulted in a 10.4 times statistically higher surgical failure rate, while a 15% bone loss resulted in a 24.4 times statistically higher failure rate Complications Axillary nerve palsy posterior branch of the axillary nerve is at risk during arthroscopic stabilization travels within 1 mm of the inferior shoulder capsule and glenoid rim at risk during suture passage at the posterior inferior glenoid Overtightening of posterior capsule can lead to anterior subluxation or coracoid impingement