What is this condition?
Impingement in the shoulder generally refers to the rotator cuff tendons becoming trapped or caught between the humeral head (the ball) and the acromion (part of the shoulder blade) in certain positions of the arm. Lifting the arm away from the body (abduction) or overhead tends to produce impingement. It can be caused by a spur or projection of bone that has grown on the front of the acromion, which means that it digs on the tendon as the arm is raised. In combination with the bone spur, there is a ligament in this area (coraco-acromial ligament) that is also usually thickened, and hence reduces the space available for the tendons. It is not known why the spur develops, but some people are more prone to develop this condition if they have a “hooked” acromion, which has usually been present from birth and is an anatomical variant. Impingement leads to inflammation of the subacromial bursa, which is a thin membrane that lies on top of the rotator cuff tendons. Traditionally, it was thought that continued abrasion of the rotator cuff tendons by the bone spur is the mechanism by which the rotator cuff tendons tear, although recent research has cast doubt on that theory.
Who gets this condition?
This condition typically occurs in the middle aged and equally between males and females. People whose jobs involve a lot of overhead activity may also be more likely to develop this condition
What treatments are available?
First line treatment for this condition is typically non-operative. I would generally recommend a cortisone (steroid) injection, which I inject into the subacromial space. The steroid is a strong anti-inflammatory. This has the effect of reducing inflammation and swelling of the bursa and tendon and provides excellent pain relief. Once the pain has been relieved with the injection, a course of physiotherapy can be useful to restore normal movement in the shoulder and to strengthen the rotator cuff muscles, which can help prevent symptoms returning. If the steroid injection doesn’t help at all with pain relief, I would then recommend an ultrasound guided steroid injection, since it is unusual not to have any response at all to an injection. If injection(s) and physiotherapy fail to achieve a lasting satisfactory result, arthroscopic subacromial decompression surgery may then be offered.