Rheumatologic aspects of painful conditions affecting the shoulder.
Patients with shoulder arthritis present to the orthopedic surgeon due to joint pain and loss of shoulder motion. A differential diagnosis is established, based on the history and physical examination and selected laboratory tests and roentgenograms. Synovial fluid analysis is often very helpful in the diagnosis of shoulder arthritis and critical for differential diagnosis of inflammatory, degenerative, and septic arthritis. Shoulder involvement in primary osteoarthritis is uncommon. The shoulder is rarely the initial joint involved in rheumatoid arthritis. Several uncommon conditions, e.g., amyloid arthropathy and reflex sympathetic dystrophy syndrome, may present early and frequently in the form of shoulder pain. The results of treatment are determined by etiology of shoulder joint disease. Patients with shoulder involvement in rheumatoid arthritis generally respond to the basic management for rheumatoid arthritis. Physical therapy to improve the range of motion of the shoulder and anti-inflammatory medications, including intra-articular corticosteroids, are helpful in most cases.