Posterior superior glenoid impingement: expanded spectrum.

Posterior superior glenoid impingement is a recently recognized mechanism of injury producing rotator cuff injury in athletes. Usually the mechanism is repetitive overhand activity such as throwing. A survey of the author's practice was undertaken to show a wider spectrum of this mechanism both in the activity that caused it and the number of structures at risk of injury from this mechanism. The survey revealed 11 patients who had a clear recollection of their mechanism of injury and an objective documentation of the injury by arthroscopy or imaging studies. The majority of shoulders had damage to more than one of the five structures at risk from this mechanism of injury. Six cases were not sports related. Glenoid impingement may injure one or more of the following: (1) superior labrum, (2) rotator cuff tendon, (3) greater tuberosity, (4) inferior glenohumeral ligament or labrum, and (5) superior glenoid bone. Injury to more than one structure may be the rule and injury to one structure may indicate investigation of the other four.