Rotator Cuff Tears
The rotator cuff muscles hold the glenohumeral joint in place and work in concert with larger muscles to move and provide power to the shoulder.
The rotator cuff is composed of four muscles that work together to help stabilize and move the shoulder. The arrangement of the tendons and other important structures around the shoulder can be seen in the drawing below on the left.
The primary function of the rotator cuff is to hold the glenohumeral joint in place while the larger muscles around the shoulder move and provide power to the arm. When the rotator cuff is inflamed or torn, the humerus (the ball part of the joint) tends to ride up in the socket to pinch and irritate the rotator cuff, acromion, and bursa. This is what causes pain and further injury (as is seen in the diagram below on the right).
When the humerus rides up, it can bump into the acromion and the AC joint (which make up the bony “roof” of the shoulder). This can eventually cause a spur to form on the undersurface of these bones, which can cause more tearing and pain in the rotator cuff tendons. With this abnormal motion, the biceps tendon and/or labrum can also be injured or torn. Finally if left the tears are untreated for a long time (decades), glenohumeral joint arthritis can occur.
The goal of all rotator cuff treatment is to decrease pain and restore shoulder function. Occasionally, through physical therapy and strengthening, the other muscles of the shoulder and rotator cuff can compensate for the torn muscle, and the shoulder can often function normally despite the tear. In these cases surgery in not needed immediately. The tear does not heal itself, however, so if you choose this, we would like to keep an eye on you. The tear can enlarge over time and create further problems. If pain or loss of shoulder function persists despite non-operative modalities, then a rotator cuff repair is a treatment option.