Brian R. Neri, M.D.
Arthritis is an inflammatory condition of the joint resulting in cartilage loss and subsequent pain and disability. Osteoarthritis, the most common type of arthritis, typically affects large weightbearing joints such as the knee and hip. However, a significant number of people develop osteoarthritis in their shoulder, or glenohumeral joint, as well. Usually these patients are over the age of 60 at the time of diagnosis and may reveal a history of heavy labor or repetitive overhead activity. Other less common causes of shoulder arthritis include rheumatoid arthritis, crystalline (gouty) arthritis, post-traumatic arthritis and arthritis as a result of shoulder instability.
The predominant symptom is pain, which can be most severe at night and prevents half of patients from sleeping on the affected shoulder. The pain usually is usually felt over the outside aspect of the upper arm, but it is not uncommon for arthritic pain to be experienced in the musculature of the neck or travel further down the arm. In addition, the loss of shoulder motion, particularly rotation, is an early symptom that can affect everyday activities such as reaching behind your back or putting on your seatbelt. Women tend to be affected more often than men as well as the dominant arm more often than the nondominant side.
Diagnosis and treatment
Glenohumeral arthritis can be diagnosed in the majority of cases simply with plain x-rays taken with the shoulder in different positions. In the earlier stages of arthritis, magnetic resonance imaging (MRI) can be helpful to identify subtle areas of cartilage loss. The arthritis is graded from mild to severe depending on the extent and location of cartilage loss. As with most musculoskeletal conditions, initial treatment is comprised of nonoperative measures to control pain and regain, or at least maintain, shoulder motion. Oral anti-inflammatories, if not otherwise contraindicated, and/or injections of corticosteroid or hyaluronic acid into the joint are judiciously utilized to reduce inflammation and therefore pain. While patients can be taught exercises to be performed on their own, a supervised physical therapy program can be of benefit early in the course of the disease to improve shoulder strength, reduce pain and possibly improve motion.
A portion of patients will fail to improve with nonoperative measures and may be indicated for operative treatment. Arthroscopic treatment, the utilization of a camera and instruments through small incisions, can be beneficial to a select number of patients who have mild-moderate arthritis with mainly mechanical symptoms (locking, catching, clicking). Unfortunately, for more severe arthritis, the results are less predicable and only provide short-term relief.
Shoulder replacement or arthroplasty has been used for many decades to treat advanced shoulder arthritis. The operation consists of replacing the arthritic bone with metal/plastic components. The surgery has >90% success rates in reducing pain and preventing any further loss of motion. Current technology is making it possible to even perform this surgery in younger patients with arthritis. Future research is focused on improving the design and longevity of the shoulder implants to prevent loosening and/or wear over time, and therefore the need for additional surgery.