What is a disorder of the AC-joint of the shoulder?
The AC-joint (or acromioclavicular joint) is situated between the collarbone and a shoulder blade bone. Irritation and sprains of this joint can cause shoulder pain.
Pain can also be due to the ageing process that causes osteoarthritis of the AC-joint. It can also arise following injury of the shoulder, for example a fall onto the shoulder. It is also often seen in whiplash injuries. This is caused by the safety belt as it is positioned over the collarbone that is close to the AC-joint.
Signs and symptoms
The symptoms are pain in the shoulder that increases on use, specifically when the arm is lifted higher than a ninety-degree angle. Also pain at night and not being able to sleep on the affected shoulder are often indications of inflammation of the AC-joint.
How are AC-joint disorders diagnosed?
The diagnosis is made on the patient's pattern of symptoms. When a doctor carries out physical examination for shoulder problems, there are three useful shoulder tests: raising the arm out to the side, holding the arm along the body and turning it outwards, and bringing the arm over to the unaffected shoulder horizontally. In addition, a neurological examination has to be done to exclude a disc prolaps of the neck.
Do I need additional examinations?
- Blood tests if a systemic disease such as rheumatism is suspected.
- If shoulder symptoms persist for a long time: X-rays, ultrasound and an MRI scan
- A bone scan if a tumour is suspected.
What are my treatment possibilities?
Interventional pain treatment
- Local injection into the AC-joint