The term „impingement syndrome” was first used by Professor Charles S. Neer in 1972. He described a situation where the movement of the humerus causes entrapment of soft tissues, and, as a result, contributes to painful inflammation.
Observing the structure of the shoulder joint, we can see that between the head of the humerus and the acromion there is a small gap through which the muscle layer passes. These are the muscles of the rotator cuff. They allow us to rotate the arm as well as flex and extend the shoulder joint. Between the muscular layer and the acromion there is a kind of a cushion that ensures good glide of the two surfaces relative to each other. It is a subacromial bursa.
Impingement Syndrome – couses
An impingement syndrome can occur in anyone who has a narrowed subacromial space and often moves their arms above their head. This ailment is especially prone to sportsmen representing such disciplines as tennis, swimming, volleyball, weightlifting, javelin and hammer throws.
There are several reasons for the narrowing of the shoulder space. It may, for example, result from an imbalance in the muscles that causes the entire humeral bone to approach the acromion. Another reason for the narrowing of the space is the deformation of the edge of the acromion with its downward curve. Other causes include arthrosis of the acromioclavicular joint, thickening and calcification of the coracoacromial ligament that forms the top of the shoulder joint, and finally the lack of union between the individual nuclei of the ossification of the acromion.
This all causes the muscles of the rotator cuff and the subacromial bursa rub against the acromion and the coracoacromial ligament during tendon movements. As a result of mechanical irritation, inflammation arises. Inflammation is accompanied by swelling of the soft tissues, which further narrows the subacromial space and intensifies pain. Chronic inflammation develops that can eventually damage the tendons of the rotator cuff.
Symptoms of Impingement Syndrome
The most common symptoms of impingement syndrome:
- pain during active flexion and extension within 80-120 degrees,
- stabbing pain on sudden extension or flexion,
- tenderness in the area of the acromion,
- disturbance of the normal brachio-scapular rhythm,
- pain while sleeping on the affected shoulder.
A careful examination allows a doctor to recognize what is happening with the shoulder joint. In order to confirm the diagnosis, an ultrasound can be performed, which will show inflammation in the subacromial bursa and assess the structure of the cone tendons. Due to the fact that the ultrasound is a dynamic examination, we can assess in motion which structures are wedged during abduction or flexion in the shoulder joint.
Treatment of Impingement Syndrome
With a minor impingement syndrome, with no damage to the cone tendons, properly conducted rehabilitation together with anti-inflammatory treatment has a chance of success. Stretching and conditioning exercises should be continued, excluding overhead activity. Single injections of steroid drugs are allowed to reduce inflammation.
Surgical treatment should be considered in the event of an exacerbation of the problem and evident anatomical changes causing stasis or in the case of tendon damage. Such a procedure can be performed using the arthroscopic method by making only two small incisions in the skin. During the surgery, the inflamed subacromial bursa and the coracoacromial ligament are removed. Also, the folded edge of the shoulder process can be aligned, or lesions from the degenerated clavicular joint can be removed. The whole procedure is called subacromial decompression.
After the surgery, rehabilitation for 3-4 months is recommended. Arms are not immobilized and immediately after the procedure, passive and active movements in the joint begin. The treatment, rehabilitation and patient’s discipline ensure efficient recovery.