POSTERIOR OSSIFICATION OF THE SHOULDER - THE BENNETT LESION - ETIOLOGY, DIAGNOSIS, AND TREATMENT

We report a series of ossific lesions of the posterior inferior glenoi d in a group of elite baseball players. We hope to clarify the etiolog y, diagnosis, and treatment of the Bennett lesion. From August 1985 to August 1991, we identified six professional baseball pitchers and one college pitcher with evidence of ossification of the shoulder on plai n radiographs, computed tomography, or magnetic resonance imaging. Art hroscopic examination was performed in all cases. All seven players ha d identifiable posterior labral injury on arthroscopic examination; si x of these seven also had varying degrees of undersurface posterior ro tator cuff damage. No anterior tissue damage, anterior instability, or subacromial impingement was noted. No ossification was identified art hroscopically. Intraarticular labral and rotator cuff tears were debri ded arthroscopically and patients underwent rehabilitation for 4 to 6 months after surgery. Six of the seven athletes returned to preinjury performance levels; however, one pitcher is no longer playing competit ive baseball. The Bennett lesion is an extraarticular posterior ossifi cation associated with posterior labral injury and posterior undersurf ace rotator cuff damage. It is not, however, a result of traction stre sses in the region of the triceps insertion. Recognition is important for identification and treatment of the lesion and associated patholog ic damage.