Loss of chondrolabral containment of the glenohumeral joint in atraumatic posteroinferior multidirectional instability.

BACKGROUND: Although the cause of posteroinferior instability of the shoulder has not been fully defined, glenoid version can be more completely measured when chondrolabral structures are included because conformity and containment of the glenohumeral joint are integral functions of both the articular cartilage and the labrum. The purpose of this study was to use magnetic resonance imaging-arthrography to evaluate the chondrolabral containment of the glenohumeral joint in patients with atraumatic posteroinferior multidirectional instability of the shoulder. METHODS: We evaluated four measurements (osseous and chondrolabral glenoid version, labral height, and glenoid depth) on T2-weighted axial magnetic resonance-arthrography images of thirty-three shoulders with atraumatic posteroinferior multidirectional instability. Shoulders with a documented labral tear were excluded. The measurements were compared with those of thirty-three age-matched controls without glenohumeral pathology. The angles of version of the osseous and chondrolabral portions of the glenoid were measured in three consecutive planes (superior 25%, middle 50%, and inferior 75% in relation to the superior lip of the glenoid) perpendicular to the long axis of the glenoid. RESULTS: The shoulders with posteroinferior instability had greater retroversion of both the osseous and the chondrolabral portion of the glenoid in the middle and inferior planes. The chondrolabral portion of the glenoid had more retroversion than the osseous portion in the inferior plane. The height of the posterior portion of the labrum was decreased in the inferior plane in the shoulders with instability. Glenoid depth in the middle and inferior planes was significantly shallower in the shoulders with instability. CONCLUSIONS: Loss of containment in the chondrolabral portion of the glenoid in the middle and inferior planes is a consistent finding in shoulders with atraumatic posteroinferior multidirectional instability and is associated with loss of posterior labral height. It is unclear whether the retroversion of the posteroinferior aspect of the labrum is a cause or a consequence of atraumatic posteroinferior multidirectional instability, but this factor should be considered during surgical repair.

Arthroscopic anterior stabilization of the shoulder: two to six-year follow-up.

BACKGROUND: The purpose of this study was to evaluate prospectively the surgical outcomes of arthroscopic repair of anterior capsulolabral lesions with use of suture anchors in a large series of patients who were followed for two to six years. METHODS: We evaluated the results of arthroscopic Bankart repair with use of suture anchors and nonabsorbable sutures in 167 patients with traumatic recurrent anterior instability of the shoulder. The mean age at the time of the operation was twenty-five years. Preoperatively and at the time of follow-up (at a mean of forty-four months), the patients were assessed with three objective outcome measurement tools (the Rowe score, the University of California at Los Angeles [UCLA] shoulder rating scale, and the American Shoulder and Elbow Surgeons [ASES] score) and two subjective measurement tools (pain and function visual analog scales). The recurrence rate, range of motion, and risk factors for postoperative recurrence were evaluated. RESULTS: All shoulder scores improved after surgery (p < 0.001). According to the Rowe scale, 130 patients (78%) had an excellent score; twenty-nine (17%), a good score; six (4%), a fair score; and two (1%), a poor score. Overall, the rate of postoperative recurrence of instability was 4% (one dislocation, two subluxations, and four positive results on the anterior apprehension test). Postoperative recurrence was related to an osseous defect of >30% of the entire glenoid circumference. In the patients with recurrent postoperative instability, the episodes were less frequent than they had been preoperatively and shoulder function was related to activity level. A revision arthroscopic Bankart repair stabilized three of the four shoulders in which it was performed. One hundred and fifty-two patients (91%) returned to >/=90% of their preinjury activity level. The mean loss of external rotation (and standard deviation) was 2.0 degrees +/- 4.0 degrees. CONCLUSIONS: We found that, in contrast to previous reports on the results of arthroscopic repair, arthroscopic capsulolabral repair with use of suture anchors can provide satisfactory outcomes in terms of recurrence rate, activity, and range of motion.