Acute Osteomyelitis in the Proximal Humerus Caused by Pyogenic Glenohumeral Arthritis in an Elderly Patient

Reports of osteomyelitis in the proximal humerus with pyogenic glenohumeral arthritis of adjacent joints mostly involve pediatric patients. Nowadays, osteomyelitis that is secondary to adjacent pyogenic glenohumeral arthritis is extremely rare, even more so in adults than in pediatrics. We report a rare case of the pyogenic glenohumeral arthritis followed by osteomyelitis of the proximal humerus in an elderly patient. Initially, we diagnosed a case of pyogenic glenohumeral arthritis only, which, despite arthroscopic synovectomy, did not resolve and severe pain continued. Subsequent radiological imaging, performed after our suspicion of a secondary involvement, allowed us to diagnose osteomyelitis combined with the pyogenic glenohumeral arthritis, which we had overlooked because of the extreme rarity of the condition in adults since the antibiotic era began.