Shoulder (glenohumeral joint) osteoarthritis is less common than arthritis affecting the knee or hip, which are weight bearing joints. Shoulder arthritis is classified as being either primary or secondary.
What Causes Shoulder Arthritis?
Primary arthritis tends to be seen in adults over the age of 60 as a result of “wear and tear.” Patients under the age of 60 with shoulder arthritis usually develop it secondary to prior shoulder trauma, osteonecrosis, infection, or complications from surgery. Shoulder dislocations are the most common type of shoulder trauma that leads to shoulder arthritis. Dislocation events can injure the bone and cartilage of the socket (glenoid) or humeral head, predisposing the shoulder to premature arthritis. Other conditions such as chronic oral steroid use, alcoholism, cancer therapy consisting of radiation or cytotoxic drugs can cause osteonecrosis whereby the bones of the shoulder joint lose their blood supply, die, and collapse leading to arthritis.
Symptoms of Shoulder Arthritis
Patients with shoulder arthritis tend to complain of a deep seated, dull pain in the shoulder. The pain is often located along the posterior aspect of the shoulder. Patients often say they have difficulty sleeping due to the pain. The pain can become sharp and stabbing with activities that force the shoulder into extreme ranges of motion. Over time, patients tend to lose shoulder range of motion and get stiffer. Complaints of weakness are uncommon unlike with rotator cuff tendon tears.
Diagnosing Shoulder Arthritis
Plain x-rays show shoulder arthritis quite well. X-rays can also show if there was an old fracture of the shoulder that may have led to the arthritis or whether there is osteonecrosis and collapse of the humeral head. MRI may be needed to assess the shoulder for focal cartilage defects or for associated rotator cuff tendon or biceps tears.
Treatment for Shoulder Arthritis
For my patients with shoulder arthritis, I initially recommend non-surgical management. This consists of avoiding repetitive overhead sports (ie. swimming, certain weight lifts), physical therapy to help regain any lost motion or strength, natural anti-oxidants in your diet (ie. green leafy vegetables and whole fruit and minimizing the consumption of processed foods), natural anti-inflammatory supplements such as Tumeric, oral anti-inflammatory medications, and various types of injections from a simple steroid injection to a platelet rich plasma (PRP) injection or stem cell injection.
Over time these non-surgical treatments may no longer provide the relief that they once did. Once these treatments have been exhausted, the best surgical option depends on the patient’s age and activity level. An older person might be very well served by a total shoulder replacement whereas this is not a good option in a 50-year-old carpenter with shoulder arthritis as they would prematurely wear out the implant.
In younger patients with shoulder arthritis, one could consider doing an arthroscopic debridement of the shoulder joint. In this surgery, loose bone and cartilage fragments can be removed from the joint, flaps of cartilage can be smoothed, a diseased biceps tendon can be repaired, bone spurs removed if becoming impinged, and any tightness of the capsule restricting motion can be released. This procedure can help improve mechanical symptoms and pain, but it usually does not alleviate all pain as there is no cure for the arthritis itself. Over time, the arthritis tends to worsen and eventually these patients may go on to a shoulder replacement surgery.