Posterior Ossification of the Shoulder: The Bennett Lesion

Abstract

We report a series of ossific lesions of the posterior inferior glenoid in a group of elite baseball players. We hope to clarify the etiology, 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 shoul der on plain radiographs, computed tomography, or magnetic resonance imaging. Arthroscopic examina tion was performed in all cases. All seven players had identifiable posterior labral injury on arthroscopic ex amination ; six of these seven also had varying degrees of undersurface posterior rotator cuff damage. No an terior tissue damage, anterior instability, or subacromial impingement was noted. No ossification was identified arthroscopically. Intraarticular labral and rotator cuff tears were debrided arthroscopically and patients un derwent rehabilitation for 4 to 6 months after surgery. Six of the seven athletes returned to preinjury perform ance levels; however, one pitcher is no longer playing competitive baseball.

The Bennett lesion is an extraarticular posterior os sification associated with posterior labral injury and pos terior undersurface rotator cuff damage. It is not, how ever, a result of traction stresses in the region of the triceps insertion. Recognition is important for identifi cation and treatment of the lesion and associated patho logic damage.