Synonyms in a broader sense
Shoulder joint arthrosis, acromioclavicular joint arthrosis, AC joint arthrosis, clavicle, clavicle, acromion, shoulder joint, arthrosis ACG
Introduction
The acromioclavicular joint (AC joint) is the joint between the acromion and the clavicle. Through a lot of sport, physical work or after injuries, signs of wear and tear can develop in this joint, which is called arthrosis.
Causes
The acromioclavicular joint, between collarbone and acromion, is exposed to high mechanical shear stress. For this reason, degenerative changes in the joint are often visible on X-rays. Even after an injury to the shoulder joint, e.g. a rupture of the joint capsule, degenerative changes of the joint and signs of wear and tear can occur.
The joint capsule and the bursa inside it can wear out over the years due to the high stress on the joint. Thus, the “buffer” between the two ends of the bone gradually becomes smaller and can be completely worn out in the final stage (acromioclavicular joint arthrosis). In this case, the bone ends rub freely against each other and wear out.
As a result, the joint gap becomes narrower and the bone is remodeled, resulting in bony neoplasms. If these grow upwards, they can come into contact with the tendons of the muscles that run there. By constantly rubbing the tendons on the bony projections, they can lose their function over time and thus accelerate the development of acromioclavicular joint arthrosis. The permanent friction also causes severe pain.
Symptoms
In many cases of arthrosis of the acromioclavicular joint, there is often pain in the shoulder joint at certain points, which can become more severe due to stress. Due to the bony changes in the shoulder joint, individual bone neoplasms can lead to different types of pain. If these new bone formations grow upwards, they can become visible from the outside as painful bulges above the shoulder joint.
Downwardly growing new bone formations can lead to irritation of the tendon and bursa. These occur mainly in the upper arm and during rotational movements of the arm. Some patients describe the symptoms of acromioclavicular joint arthrosis as a pulling pain in the neck.
However, the overall pain symptomatology varies greatly from individual to individual and therefore cannot be generalized. More about this:
- Symptoms of arthrosis
The pain is usually easy to localize by those affected. Usually the pain only occurs when the shoulder is moved.
The pain initially occurs during typical movements such as push-ups or overhead work. The quality of the pain is usually described as stabbing. In addition, if tendons and ligaments are also affected by the arthrosis, the pain can radiate into the upper arm or even towards the elbow. If the shoulder is inflamed, lying on the shoulder can also cause pain.