Ruptures of the rotator cuff commonly are unrecognized and mistakingly diagnosed "bursitis," because they occur without clinical or radiological evidence, other than by arthrographic study. Conventional roentgenograms, correlated with 200 arthrographic studies of shoulder dysfunction, reveal six degenerative changes appearing after the fourth decade, any four of which if present, indicate a 90% probability that arthrographic study will reveal a ruptured rotator cuff. Arthrography remains without peer as a diagnostic tool in the evaluation of shoulder pain of local origin.
Kernwein GA. Roentgenographic Diagnosis of Shoulder Dysfunction. JAMA. 1965;194(10):1081-1085. doi:10.1001/jama.1965.03090230049011