A rotator cuff injury is an injury to one or more of the four muscles in the shoulder. This shoulder injury may come on suddenly and be associated with a specific injury such as a fall or it may be something that gets progressively worse over time with an activity that aggravates the muscle. The type of injury can range from an inflammation of the muscle without any permanent damage, such as tendonitis, to a complete or partial tear of the muscle which may require surgery to fix it.
Many different ligaments are involved in stabilizing the shoulder joint, particularly in the front. The major stabilizing factors at the back of the joint are the muscles of the rotator cuff. These muscles help keep the head of the humerus in place against the shoulder blade. The rotator cuff is comprised of four muscles; supraspinatus, infraspinatus, teres minor, and subscapularis.
Rotator cuff tendonitis, also known as bursitis, or impingement syndrome, occurs when the rotator cuff gets irritated on the undersurface of the acromion. The reason this occurs is a source of some debate. Some people are born with a hooked acromion that will predispose them to this problem. Others have rotator cuff weakness that causes the humerus to ride up and pinch the cuff. This means that the bursa becomes inflamed.
Common signs of rotator cuff tendonitis include pain located primarily on top and in the front of the shoulder. Mild to moderate weakness is very common, especially when overhead activity is performed. On occasion, bursitis that occurs with rotator cuff tendonitis can cause a mild popping or crackling sensation in the shoulder.
Often the diagnosis is suggested by the symptoms. The orthopedic surgeon or primary care physician will have the patient perform various maneuvers to detect rotator cuff tendonitis. The physical examination is designed to test motion, strength, and certain positions of pain. In addition, plain x-rays can show a spur on the undersurface of the acromion. An MRI is often ordered if a rotator cuff tear is suspected. Treatment for tendonitis of the rotator cuff includes resting the injured shoulder from the activities that caused the problem and from the activities that cause pain. Ice packs applied to the shoulder and non-steroidal anti-inflammatory drugs will help reduce inflammation and pain.
Physical therapy to strengthen muscles of the rotator cuff should be started. If the pain persists or if therapy is not possible because of severe pain, a steroid injection may reduce pain and inflammation enough to allow effective therapy. If the rotator cuff has sustained a complete tear, of if the symptoms persist despite conservative therapy, surgery may be necessary.
Arthroscopic surgery can remove bone spurs and inflamed tissue around the shoulder. Small tears can be treated with arthroscopic surgery although larger tears may require open surgery through a larger incision to repair the torn tendon. Most people do recover full function after a combination of medications, physical therapy, and steroid injections. For patients with tendonitis and a bone spur, arthroscopic surgery is usually successful in restoring them to their pre-injury level of activity.