Anterior instability of the shoulder due to capsular laxity.

Thirty cases of anterior instability of the shoulder are reported where the only or pre-eminent pathological condition observed at operation was an abnormal laxity of the joint capsule. Four clinical pictures emerged - recurrent distortion, recurrent subluxation, recurrent dislocation, dislocation followed by recurrent subluxation - presumably due to increasing degrees of instability. In 13 cases, surgery consisted of stabilisation of the anterior joint capsule at the neck of the glenoid with a staple, and in 17 cases, capsulo-muscular plastic surgery with the aim of reducing the excessive width of the joint capsule and shortening the subscapularis. Satisfactory results were obtained in 90% of the cases. Although the quality of the results was not conditioned by the type of surgery used, capsulo-muscular plastic surgery appears to be the best method for the correction of the pathological condition responsible for the instability.