Just like other joints in the human body, the shoulder joint is made up of bones (the humerus and glenoid) that are lined by cartilage. Cartilage is a very smooth, soft substance that allows the humerus (ball) to move smoothly and glide along the socket (glenoid). Arthritis occurs when cartilage wears down so that the bony ends of the shoulder joint become exposed. Unlike cartilage, bone has free nerve endings and does not have a smooth surface. As a result, when the bone is exposed, movement in the shoulder can cause catching and other symptoms, because the cartilage is no longer protecting the bone.
There are many different causes of arthritis. The most common cause is osteoarthritis. Osteoarthritis occurs when the cartilage breaks down over time due to wear and tear. There is also a genetic component to osteoarthritis, and some patients may be predisposed to developing arthritis based on family history. Other causes of arthritis in the shoulder include inflammatory arthritis, such as rheumatoid arthritis. This type of arthritis usually involves irritation of the lining of the shoulder (capsule and synovium) in addition to cartilage damage. A third type of arthritis is post-traumatic arthritis. This type of arthritis occurs when cartilage is damaged following a fracture or dislocation in the shoulder joint. Over time, the injured cartilage and surrounding cartilage in the shoulder may break down further – leading to a condition similar to osteoarthritis.
- Intermittent pain, aggravated by activity
- Catching and grinding, particularly with overhead or rotatory motion
Diagnosis And Treatment
Dr. Keller considers each patient’s symptoms, as well as a detailed physical examination and x-rays to make the diagnosis of shoulder arthritis. There are many different treatment options for arthritis. Oral analgesics or anti-inflammatories, such as Tylenol or Motrin, can help relieve the symptoms, especially when one has a “flare-up” of the arthritis. Intermittent icing and limiting overhead and rotatory motion in the shoulder may also help lead to improvement in symptoms. Physical therapy is another option. A dedicated physical therapy program that promotes shoulder motion and appropriate mechanics of the shoulder may relieve certain symptoms.
Another treatment option for shoulder arthritis is injections. There are many different types of injections, including steroid injections, platelet-rich-plasma (PRP), stem cells, and visco-supplementation. When performing an injection, Dr. Keller prefers to use ultrasound for guidance. Dr. Keller can visualize the injection going into the right spot in the shoulder when using an ultrasound machine. A steroid is an anti-inflammatory medication that can help reduce the irritation in the shoulder. Visco-supplementation is a lubricating fluid that may also help reduce the irritation in the shoulder joint. Although the data supporting PRP and stem cells is limited, these injections can also reduce the inflammation in the shoulder joint, potentially leading to less pain.
In those patients who do not improve with non-surgical treatment, Dr. Keller may recommend surgery. Some patients can benefit from minimally invasive, arthroscopic surgery. This surgery is a viable option for young, active patients with arthritis who wish to avoid a shoulder replacement surgery.
When arthritis becomes severe, Dr. Keller usually recommends shoulder replacement surgery. There are several different types of shoulder replacement surgery, including a total shoulder replacement, partial shoulder replacement (hemiarthroplasty), or reverse shoulder replacement. In both a total shoulder replacement and reverse shoulder replacement, the ball and socket are replaced. In a partial shoulder replacement, only the ball is replaced with a metal prosthesis.