Arthrography and computed arthrotomography study of seventy patients with primary glenohumeral osteoarthritis.

Seventy patients with primary glenohumeral osteoarthritis underwent roentgenographic and computed tomography studies. Glenohumeral joint space loss and a normal acromiohumeral space were the roentgenographic inclusion criteria. Women made up 61% of the sample. The dominant shoulder was affected in 95% of cases and both shoulders in 41%. Mean age at first evaluation was 65 years. Arthrography showed a tear confined to the supraspinatus tendon in 16 cases (23%); no patients had tears involving more than one tendon. Computed tomography demonstrated glenoid retroversion (mean 16 degrees) but was unable to differentiate primary glenoid dysplasia from wear due to osteoarthritis. Posterior subluxation of the humeral head was found in 28 cases (40%) but was not consistently correlated with the presence of glenoid retroversion.