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AC (Acromioclavicular)Joint Arthritis

What is the Acromioclavicular Joint?

The Acromioclavicular Joint (the “AC joint”) is the bony point of the shoulder where the collarbone and the shoulder blade meet. The joint is surrounded by a capsule that protects the joint and the ligaments that support the joint. This capsule also provides joint stability. All arm motions move the AC joint.

What is Osteoarthritis?

OA is a degenerative condition that destroys the cartilage in the shoulder either as a result of a previous shoulder injury (posttraumatic arthritis); or from overuse and “wear and tear” that gradually deteriorates the joint over time. OA causes degeneration of the cartilage at the ends of the bones, causing pain and stiffness. There is no cure, but there are options to help people with arthritis to manage pain and stay active.

AC joint arthritis commonly affects people over the age of 50.

As the cartilage at the end of the bone’s degenerates over time, the space between the bones is reduced causing the bones to rub together. This can cause pain and inflammation, restricts motion, and can create bone spurs that can irritate the tendons and muscles.

It is noteworthy that some people have no symptoms, despite the destruction of the joint. Studies report that up to 50% of elderly people with AC joint arthritis have no symptoms.

What are the symptoms?

  • Tenderness at the top front of the shoulder that comes and goes and flares up.
  • Pain and stiffness which is aggravated by activity.
  • Painful activities include reaching the arm across the body to execute a backhand tennis shot, reaching behind the back to zip a zipper, and lifting a heavy item overhead. Pain and stiffness can make it impossible to swing a golf club or put on a seat belt.
  • Bone spurs can pinch and irritate the tendons, and rotator cuff muscles causing should impingement syndrome, and more pain.
  • Shoulder range of motion is rarely affected but can be painful.

How is AC joint arthritis diagnosed?

AC joint arthritis can occur without shoulder problems, but some shoulder problems like rotator cuff impingement, or tears, can exist at the same time. This is why ruling out certain diseases with similar symptoms is so important.

Dr. Stark will review your medical history and conduct a physical exam. He will order

imaging studies, including X-rays, to evaluate the joint. Arthritis can be diagnosed with x-rays, so there is little reason for additional imaging tests, unless there is reason to suspect other shoulder conditions. When that is the case, he will order an MRI to rule out other potential shoulder conditions like a torn rotator cuff.

How is AC Joint arthritis treated?

Treatment is aimed at controlling pain and slowing the degeneration of cartilage. Conservative treatment is focused on relief of symptoms and includes anti-inflammatory medications and activity modification. When that is insufficient to relieve pain and inflammation, cortisone injections can help to relieve pain.

When conservative treatment is unable to provide enough relief for the patient to return to normal activity, joint surgery may be considered.

AC joint surgery involves removing the end of the clavicle or collar bone to increase the space between the ends of the bones, to prevent the bones from rubbing together. This surgery is done with minimally invasive arthroscopy but can also be done as an open procedure. Arthroscopic surgery can also detect other problems in the joint, which can be treated at the same time. The goal is long-term pain relief. Recovery from open surgery takes longer and is more painful than minimally invasive surgery, because some of the muscles in the joint must be detached and reattached.

The length of recovery will depend on the procedure performed. Dedication to rehabilitation will allow patients to return to full activities. Dr. Stark has office in Carlsbad.