The anatomy of the shoulder can be rather confusing, with all the tendons and muscles that give us the ability to move our arm in all different directions. The joint itself is a ball and socket joint allowing for rotational movement unlike the elbow which is a hinge joint. The humeral head and the glenoid make up this joint. A group of muscles that play a big role in how we can move our arms is the rotator cuff. This is made up of 4 muscles; supraspinatus, infraspinatus, subscapularis and teres minor.
Damage to this rotator cuff can cause difficulties and pain on moving the shoulder. Rotator cuff tears commonly present with impingement of the tendons also. Tears are usually due to chronic degenerative change within the muscle seen in older patients. They can be due to trauma however there is usually some underlying degeneration of the muscles prior to the traumatic incident that results in a tear.
Rotator cuff tears can be detected through clinical examination of the shoulder. Pain is usually located over the deltoid region with a loss of range of movement of the arms when actively moved, however when the clinician assesses the range of movement passively this is intact. Patients are unable to abduct their shoulder without first lifting their shoulder up, this is due to deltoid muscle doing most of the work. There are a few clinical test that can detect a rotator cuff tear, the drop arm test is where the arm is lifted passively above the patients head and they are asked to hold it there. Those with a severe rotator cuff tear their arm drops down once the examiner has let go of the arm, due to supraspinatus muscle tear.
Treatment options depend on the extent of the tear. Simple activity modification and physiotherapy might be enough to help whereas with major tears reverse shoulder joint replacement might be necessary. Joint replacement is used as a last resort and usually reserved for elderly patients. This is as it is final line treatment so there is little else that can be done if it fails. Surgical repair of the tendons might be possible in some cases but this depends on the extent of the tear.