The rotator cuff consists of four muscles and their tendons. These surround the ball of the shoulder joint.
The muscles fine tune the movements of the shoulder joint and assist other large muscles in moving the arm.
The tendons run under the acromion (the prominent bone at the tip of the shoulder – part of the shoulder blade) where they are very vulnerable to being damaged. This can lead to a tear resulting in a painful, weak shoulder.
The tendon of the rotator cuff passes through a narrow space between the top of the arm bone and a prominent bone on the shoulder blade (the acromion). The tendon is very vulnerable to being pinched here when the arm is moved, especially above the head. Over time this pinching can lead to tears of the tendon; the chance of this increases as we get older.
When repeated tearing occurs, the fabric of the tendon becomes weakened and finally, like the cloth at the knees of old trousers, splits. This leads to pain, which can be severe. Weakness of the shoulder can occur, often with clicking and crunching on movement.
Other forms of treatment such as injection and physiotherapy are available, but sometimes it is necessary to repair the tendon. How well this does will depend upon the size of the tear. If we think about the trousers again, the bigger the split in the cloth, the more difficult is the repair and the more likely the repair is to re-tear. Your consultant will have discussed this with you.