Teaching Case

Recurrent anterior dislocation of left shoulder

32 year old professional guitarist who first dislocated his shoulder playing American football ten years back. Since then he has had at least seven complete anterior dislocations and innumerable partial events. The last episode occurred during sleep while he was putting his hand behind his head. After relocating the shoulder in the Accident and Emeregency department, the patient had an outpatient orthopaedic referral. On examination in the clinic, he had a normal shoulder contour and a functioning axillary nerve. He had full range of movements. Apprehension test and anterior relocation test were positive.

An MR arthrogram was performed which showed detachment of the anteroinferior glenoid labrum with intact scapular periosteum and a Hill Sach’s defect in postero superior humeral head. Other findings included a posterior labral tear, absent anterosuperior glenoid labrum along with thickened middle gleno humeral ligament. Arthroscopy confirmed the anterior labral detachment and a Bankart repair was performed.

Anteroinferior instability is the most common type involving the glenohumeral joint, occurring in 95% of patients (1). Tears of the labroligamentous complex is a frequent association often with fractures of the bony glenoid and humeral head. MR arthrogaphy is now the investigation of choice and provides excellent depiction of the intra articular structures. In anterior labroligamentous periosteal sleeve avulsion (ALPSA lesion) the torn anteroinferior labrum is displaced inferomedially but remains attached to the scapula by an intact scapular periosteum. In our case this was associated with a congenitally absent anterosuperior labrum and a thickened middle glenohumeral ligament which together is referred to as the Buford complex.