The pain from either impingement or rotator cuff tears tends to be felt in the lateral upper arm in the area shown on the picture and the pain often travels down the arm to the elbow. It doesn't normally travel any lower than this and pain shooting all the way down the arm to the forearm is more usually due to a problem in the neck. For more information please read the following sections.
Normal shoulder function relies heavily on the correct function of four small muscles, termed the rotator cuff. These muscles are connected to the humeral head by tendons. These tendons are susceptible to wear and tear degeneration with age. In fact, the majority of sixty-year olds are thought to have tears in these tendons. However not all tears produce symptoms. Many patients do complain of a characteristic impingement pain when lifting their arm. This may be due to poor function of the rotator cuff leading to pinching of the tendons under the acromion, a bony arch which covers the rotator cuff tendons. It may also be due to an abnormality of the acromion. Normally the acromion is flat. However, abnormal thickening or curvature (hook) of the acromion can rub and pinch the bursa. This in turn can lead to inflammation of the bursa and tendons. Impingement can be treated by steroid injections and physiotherapy. If rotator cuff function is improved then the space in which the tendons move is increased, reducing impingement. If a patient fails to improve, then surgery can be performed to remove part of the undersurface of the acromion. This removes the part of bone on which the tendons are catching. This arthroscopic procedure is called a sub-acromial decompression. Sub-acromial decompression should only be performed as a key hole procedure as historical open techniques cause significant avoidable damage to the deltoid muscle.
Rotator Cuff Tear
The rotator cuff may tear suddenly following a fall or pull on the arm. This occurs most often in the middle-aged where wear-and-tear changes are already present. It can happen in younger patients with more severe injuries. Patients complain of pain and weakness, they find it difficult to lift their arm up to the side and often complain of a catching sensation when moving the arm particularly when it is lowered. Some rotator cuff tears do not require surgery as the symptoms settle with injections and physiotherapy. However patients complaining of significant weakness should be considered for a repair of the tear. Rotator cuff repairs can be performed using both arthroscopic (key hole) and open surgical techniques. Almost always at the Upper Limb Centre these procedures are performed as key hole procedures.
Occasionally local deposits of calcium salts can form in the rotator cuff. This can be painful when the calcifying material gives rise to inflammation. It can become extremely painful in an acute attack. Sometimes the calcium does not become inflamed, in this circumstance symptoms only occur if the deposit enlarges to the point that the tendon starts to catch on the overlying acromion. Calcium deposits are most frequently seen in females between 35 and 65 years of age. Treatment is aimed at removing the material, which is often of toothpaste consistency, by aspiration through a needle, usually using ultrasound to find the calcium. A steroid injection can also be helpful. If aspiration is unsuccessful then an arthroscopy can be performed and the calcium removed under direct vision. This procedure may involve a sub-acromial decompression to trim away some of the overlying bone.