Comparison of Glenoid Version and Posterior Humeral Subluxation in Patients With and Without Posterior Shoulder Instability.

Purpose: To evaluate glenoid version and humeral subluxation on preoperative multiplanar imaging of patients who underwent surgery for posterior glenohumeral instability compared with a matched group of patients who had shoulder surgery for other pathology.

Methods: All patients over a 2-year period who underwent surgery for posterior instability had preoperative magnetic resonance (MR) imaging or MR arthrogram reviewed. Patients undergoing shoulder surgery for reasons other than instability were identified as a control group and matched by sex, laterality, and age.