Arthroscopic evaluation of acute initial anterior shoulder dislocations.

Arthroscopic evaluation of patients with an acute anterior shoulder dislocation was done to identify and classify the intraarticular lesions that might predict recurrent dislocations. Forty-five shoulders fit the following criteria for inclusion in our study: initial dislocation with no prior history of shoulder problems; confirmation of the dislocation radiographically or reduction by a physician; and arthroscopy within 10 days. The 42 men and 3 women had an average age of 21.2 years (range, 14 to 28 years). Mechanism of injury was a twisting of the arm into forced abduction and external rotation, a fall on the outstretched arm, or a direct blow to the shoulder. Based on this preliminary study of 45 shoulders, we present a classification of the lesions found in the acute shoulder dislocation. Group 1 (six shoulders) had capsular tears with no labral lesions: these shoulders were stable under anesthesia and had no or minimal hemarthrosis. Group 2 (11 shoulders) had capsular tears and partial labral detachments: these shoulders were mildly unstable and had mild to moderate hemarthrosis. Group 3 (28 shoulders) had capsular tears with labral detachments: these shoulders were grossly unstable and had large hemarthrosis. They had complete capsular/labral detachments. In the past, redislocation rates have been primarily related to age at the time of initial dislocation and, to a lesser degree, the period of immobilization. We have identified the intraarticular lesions in 45 patients with an initial anterior glenohumeral dislocation and classified these shoulders into three groups based on the lesions found. By doing so, we can develop a more accurate method of determining which shoulders are prone to recurrent dislocation.(ABSTRACT TRUNCATED AT 250 WORDS)