Shoulder (Glenohumeral) Arthritis
Arthritis happens when the articular cartilage covering the bone ends become damaged and cannot glide smoothly.
Articular cartilage is the tough but smooth covering on the end of bones in most joints. It allows gliding without much resistance and cushions the ends of the bones.
The shoulder joint is similar to a ball sitting on a golf tee. Shoulder arthritis occurs when the cartilage normally covering the joint surfaces of the “ball” (humeral head) or “golf tee” (glenoid) is lost. This process generally occurs over the course of years, but may or may not cause symptoms. Shoulder arthritis is not as common as knee or hip arthritis.
Most commonly patients with shoulder arthritis notice pain, stiffness, and some change in their function. Sleeping on the shoulder may be painful and patients may also notice grinding when they move their shoulder.
There are several different causes of shoulder arthritis, including osteoarthritis, rheumatoid arthritis, arthritis after injury, arthritis after a previous surgery, arthritis that occurs after an infection of the shoulder, or arthritis that occurs when the blood supply to the humeral head dies (avascular necrosis).
In addition to arthritis, there are several other structures in the shoulder that can also cause pain. It is important for your doctor to figure out if your pain is due to arthritis, a rotator cuff or biceps tendon problem, a frozen shoulder, or neck arthritis as these all have different treatments.
The goal of all treatment for shoulder problems is to decrease pain and restore function. Often this initially involves more conservative therapies, with progression to more invasive therapy if the pain continues.
It is important to know that at this time there is no perfect way to restore articular cartilage after injury, and we are still trying to understand exactly what happens when cartilage is injured. Because of this, we can only slow down the cartilage degeneration process and/or make it less symptomatic along the way. The end result for all cartilage problems is degenerative joint disease, also known as osteoarthritis. While conservative therapies are always our first line of treatment, if pain and loss of shoulder function persist then more invasive options should be considered such as shoulder replacement surgery.