Shoulder arthritis is a condition in which the normally smooth cartilage covering the ball (humeral head) and socket (glenoid) of the shoulder joint is lost due to disease, wear and tear, or injury. Due to the loss of this cartilage, there is bone-on-bone rubbing between these two joint surfaces. The rubbing causes pain, stiffness, difficulty sleeping, and hinders the ability to work, play sports, and perform other daily activities.
Causes of Shoulder Arthritis
There are several forms of arthritis that can impact the shoulder joint.
- Osteoarthritis is a degenerative, “wear-and-tear” type of arthritis, where the cartilage in the shoulder joint gradually wears away. As the cartilage deteriorates, it becomes worn and rough, and the space between bones decreases causing the bones of the joint to rub more closely against one another.
- Rheumatoid Arthritis: is an autoimmune disease where the immune system attacks its own tissues, damaging normal tissues such as cartilage, ligaments, and bone. Rheumatoid arthritis usually attacks multiple joints and affects the same joint on both sides of the body.
- Posttraumatic Arthritis refers to arthritis that forms as the result of an injury, such as a dislocated shoulder or a fracture.
- Rotator Cuff Tears arthritis can develop in the shoulder as the result of a large, untreated rotator cuff tear. A torn rotator cuff can cause the humerus to rub against the acromion (shoulder blade), damaging the surfaces of the bones in the shoulder joint.
- Avascular Necrosis (AVN) occurs when blood supply to the head of the humerus is disrupted. Bone cells die without a proper blood supply, and AVN can cause bones in the shoulder to deteriorate and collapse. AVN is caused by heavy steroid usage, heavy alcohol consumption, sickle cell trait, and traumatic injury, such as a fracture.
The most common symptoms of shoulder arthritis include:
- Pain that increases with activity and decreases with rest
- Stiffness in the shoulder joint
- Hearing or feeling a grinding, clicking, or snapping as you move the shoulder
- Difficulty using the arm for activities overhead and out to the side
- Limited range of motion
- As symptoms progress, night pain is common and sleeping may become more difficult
Shoulder arthritis is diagnosed by physical examination and proper X-rays. During the physical exam, your physician will look for weakness in the muscles, passive (assisted) and active (self-directed) range of motion, and sign of injury to the muscles, tendons, and ligaments surrounding the joint. Joint injections can also help confirm the diagnosis. If patients receive temporary relief from an injection, a diagnosis of arthritis is supported.
Treatment of shoulder arthritis can range from non-surgical treatment like range-of-motion exercises and non-steroidal anti-inflammatory medications, to surgical intervention such as a total shoulder replacement or even a reverse total shoulder arthroplasty. A shoulder surgeon experienced in joint replacement can determine if the arthritis is the cause of the problem and if surgery would be beneficial. The goal of shoulder replacement is to restore the best possible function of the joint. This is done by removing scar tissue, balancing muscles, and replacing the destroyed joint surfaces with artificial ones.