The acromio-clavicular joint (also known as the A/C joint or ACJ) forms part of the shoulder. It is located near the collarbone at the top of the shoulder.
The ACJ is prone to pain and inflammation which can be caused by either a sudden (acute) injury such as a direct blow/hit, or due to repeated overloading/overuse of the joint.
The cumulative effects of overload and degeneration can eventually cause the ACJ to develop osteoarthritis. In some cases, osteolysis may also develop. Osteolysis is the disappearance of bone tissue, and it is characterized by the disintegration of the collarbone.
ACJ Degeneration is progressive, with localised pain around the ACJ area being a common symptom for patients. Tenderness is localised and can be felt at the tip of the shoulder, in some cases swelling may also occur. Activities which place stress on the ACJ are usually painful, such as lying on the shoulder or any other movement which compresses the ACJ. People attempting physical activity such as bench presses, push-ups and overhead activities may notice a clicking or grinding sensation in the shoulder.
It is important that ACJ degeneration is managed carefully, following a clearly defined and multi-stage process:
- Diagnosis – an X-ray is required to determine the existence and extent of degeneration.
- Patients should reduce their use of the ACJ joint, as this will help to reduce inflammation and load related stress. It is recommended that alternative physical activities and work habits are adopted if possible. Ice should be used on a regular basis for pain relief, as well as anti-inflammatory tablets. Some patients may prefer cortisone injections instead.
- Progress should be monitored for 2-3 months. If no improvement is observed, surgery is an option to explore. This is usually performed by keyhole/arthroscopic surgery, and it involves an excision of the distal clavicle.