Since 1980, several authors have reported successful treatment of multidirectional instability with use of the inferior capsular shift. Neer's initial report in a series of 32 patients noted only one unsatisfactory result. One decade later he reported that ¿more than 100 additional inferior capsular shifts have been done with similar satisfactory results.¿ The authors have reported preliminary results following 75 inferior capsular shifts performed in young athletes. Eighty-nine percent were able to return to their major sport while seventy-three percent maintained the same level of competitiveness. Seven patients (9.3%) reported a single episode of probable subluxation that was not followed by recurrent instability and did not affect the final result, whereas two patients (2.7%) dislocated postoperatively. Both of these cases were associated with a traumatic episode. The average loss of external rotation was 7 deg. Altchek and Warren reported their results following a T-plasty modification of the Bankart procedure for multidirectional instability in 42 shoulders. The patient population differed somewhat because 38 of the 42 cases had a Bankart lesion or detachment of the labrum and glenohumeral ligament complex. Patient satisfaction was rated excellent for 40 (95%) of the shoulders. The average loss of external rotation was 5 deg. Altchek and Warren noted that throwing athletes were unable to throw a ball with as much speed as before the operation. Additionally, 7 of 42 shoulders (16%) demonstrated 2+ or greater posterior instability postoperatively. There were four cases of symptomatic recurrent instability, one anterior and three posterior, while one patient required a posterior stabilization 2 years postoperatively. Recently Cooper and Brems' reviewed their series of 43 shoulders in 38 patients with a minimum 2-year follow-up after inferior capsular shift. Thirty-nine of 43 shoulders (91%) were rated by the patient as satisfactory with no recurrent instability. Postoperatively recurrent symptomatic instability developed in four patients (11%). Two of these patients required subsequent revision inferior capsular shifts and one of those went on to a humeral head replacement for arthritis of dislocation. The latter patient had received a prior Bristow procedure. Cooper and Brems concluded that the inferior capsular shift procedure provided satisfactory objective and subjective results. Failures and recurrences of symptomatic instability generally occurred in the early postoperative period less than 2 years following surgery. Their findings did not demonstrate a deterioration of the results, with a follow-up of 6 years. The authors recently reported the results after inferior capsular shift from classic multidirectional instability in 52 shoulders. Thirty-six shoulders were approached from the anterior side and 16 from posterior. All were completely immobilized in a brace for 6 weeks postoperatively. Forty-nine shoulders were observed over 2 to 11 years (average: 5 years). Satisfactory results were achieved in 94% of cases. Turkel and coworkers demonstrated that anterior glenohumeral stability is provided by varying regions of the capsule depending on arm position. Similarly, Warner and coworkers have recently demonstrated that inferior humeral translation is restrained by the anterosuperior capsule and ligaments with the arm at the side, and by the inferior capsule and ligaments with the arm in abduction. This is consistent with the clinical findings of Neer and Foster, who described inferior humeral translation with the arm at the side and with the arm in abduction in patients with multidirectional instability, and emphasized reducing redundant capsular volume on all sides at the time of surgical reconstruction. The capsular shift procedure eliminates laxity in the rotator interval, anterosuperior capsule, and anteroinferior capsule.(ABSTRACT TRUNCATED)