Understanding multidirectional instability of the shoulder.

OBJECTIVE: To provide an overview of the evaluation and treatment of the patient with multidirectional shoulder instability. DATA SOURCES: I searched MEDLINE for the years from 1980 to 2000 using the key words "shoulder joint," "instability," "dislocation," "multidirectional shoulder instability," and "inferior capsular shift." DATA SYNTHESIS: Multidirectional instability is symptomatic glenohumeral subluxation or dislocation in more than 1 direction: anterior, inferior, or posterior. The primary pathology is a loose and patulous capsule, and the entity is more common than previously recognized. Multidirectional instability affects young, sedentary patients with generalized ligamentous laxity, often with bilateral symptoms and an atraumatic history, but it also affects athletes, many of whom have sustained injuries. Patients with multidirectional instability may also have Bankart lesions and humeral head impression defects. CONCLUSIONS/RECOMMENDATIONS: Patients with multidirectional instability must be identified before appropriate treatment can be initiated. If a course of rehabilitation fails to improve the patient's symptoms, an inferior capsular shift procedure has been demonstrated to be an effective surgical option.