Glenohumeral instability.

Glenohumeral instability is an important cause of shoulder pain and disability in an active population. An awareness of the prevalence of recurrent instability, either in the form of dislocation or subluxation, is particularly useful in the assessment of the young athlete presenting with shoulder pain. Young adults presenting with rotator cuff tendinitis may have an underlying instability as the primary cause of their problem. A careful clinical examination should determine whether the instability is voluntary or involuntary, of traumatic or atraumatic onset, and the primary direction of the instability, as these factors have important implications with regard to treatment. Anterior glenohumeral instability is most common and the incidence of recurrent instability following on from an initial dislocation is high in the young active patient. An intensive rehabilitation programme is indicated for all initial dislocations or subluxations but surgery may become necessary after failure of conservative treatment. Care must be taken to determine accurately those patients with voluntary or multi-directional instability and a longer trial of conservative treatment is indicated here, as results of operative treatment in those cases are less favourable. Conservative treatment should be directed at strengthening the dynamic stabilizers of the shoulder joint, notably the rotator cuff muscles. Additional X-ray views are needed to demonstrate all the radiological changes associated with recurrent instability and further evaluation with examination under anaesthesia and arthroscopy is beneficial in the assessment of these patients. Arthroscopic surgery also has a role in the treatment of patients with symptomatic labral pathology and is now being used to perform stabilization procedures in selected cases. Many operative procedures have been described for stabilization of the shoulder and these should be directed at correcting the pathology present. Restoration of the patient's flexibility and strength postoperatively is essential, especially in the athlete in order to allow a full return to sporting activity.