The rotator cuff is made up of the tendons of four muscles. They are the supraspinatus, infraspinatus, subscapularis, and teres minor. These muscles originate from the scapula, and their tendons merge together to form a “cuff” over the upper end of the arm (head of the humerus). The term “rotator cuff ” is an oversimplified description of the work that these muscles and tendons perform. In addition to rotating the humerus (shoulder rotation), the rotator cuff stabilizes the ball of the shoulder (humeral head) within the joint, and it depresses the humeral head as the arm is lifted.
Most rotator cuff tears occur in the supraspinatus tendon, but other parts of the cuff may also be involved.
A cuff tear may result from an injury to the shoulder, such as a fracture or dislocation. In general, rotator tears occur more commonly in people over the age of 40. When they do occur in younger patient they are usually caused by acute trauma, repetitive overhead work or sports activity. Rotator cuff tears may result from a person’s occupation; construction workers, painters, or others who do repetitive overhead work may be more at risk. Athletes who participate in sports requiring extensive overhead activity are also more prone to develop a rotator cuff tear; baseball pitchers, volleyball and tennis players, and swimmers commonly have shoulder discomfort that may be related to rotator cuff pathology.
Symptoms of a rotator cuff tear may develop suddenly or gradually. Acute pain usually follows trauma from a strain or tearing injury, or from a fall on the affected arm or shoulder. When the tear occurs from an injury, there may be sudden acute pain, a snapping or tearing sensation, and an immediate weakness of the arm.
More commonly, the onset is slow. Patients often feel pain that radiates from the shoulder down the side of the arm to the elbow region. Patients typically cannot sleep on the affected side at night, and they report being awakened from the discomfort if they roll onto that side in their sleep. Other symptoms may include stiffness and loss of motion. It may be difficult to reach overhead for hair grooming. Tasks that once seemed simple, such as driving a car or reaching behind the back to fasten a bra, may become difficult and painful.
Diagnosis of a rotator cuff tear is based on a patients symptoms, the doctor’s examination, X-rays, and imaging studies such as MRI (magnetic resonance imaging). The doctor will test shoulder range of motion in several different directions, and test the strength of the muscles. The orthopaedist will also check for shoulder instability, problems with the AC (acromioclavicular) joint, and neck problems (a pinched nerve in the neck may cause pain to be referred to the shoulder).
A patient with a rotator cuff tear may have:
- Decreased muscle mass of the shoulder
- Pain when lifting or lowering the arm
- Weakness when rotating the shoulder
- Crepitus (a grinding/crackling sensation) with shoulder motion
X-rays provide a simple, quick test to determine whether arthritis is contributing to the shoulder pain. However, soft tissues such as the rotator cuff tendons cannot be seen on x-ray. For this reason, your doctor may order another test, such as an ultrasound or MRI, that allows better visualization of the soft tissue structures. This information is needed so that an appropriate treatment recommendation can be made by the doctor.
Treatment options may include:
- Rest and limited overhead activity
- Use of a sling
- Anti-inflammatory medication
- Steroid injection
- Strengthening exercise and physical therapy
In many cases, non-surgical treatment can provide substantial pain relief. In some cases the function of the shoulder can be improved with physical therapy. It may take several weeks or months to restore the strength and mobility to your shoulder.
While conservative treatment is considered appropriate for a partial thickness rotator cuff tears, there is a growing consensus that full thickness tears should be treated surgically (assuming that the patient is otherwise healthy enough to tolerate a surgery). When a cuff tendon is torn through completely, tension from the rotator cuff muscle causes the tendon to retract away from the humeral head toward the scapula. The cuff tendon will not heal back to the humerus bone on its own because it is being physically pulled away from the humerus by its own muscle. The muscle of the torn cuff will begin to waste away, or atrophy, from disuse. With time the muscle fibers are infiltrated by fatty tissue. Once this change has occurred the chances of a successful repair diminish.
Many surgical repairs can be done on an outpatient basis. The type of surgery performed depends on the size, shape and location of the tear. A partial tear may require only a trimming or smoothing procedure called a “debridement.” If the tendon is torn from its insertion on the greater tuberosity of the humerus, it can be repaired directly to the bone.
In the operating room, your surgeon will examine the undersurface of the acriomion and possibly remove part of it if it is noted to have a bone spur or be rough. This part of the procedure is called an acromioplasty. In the past, an acromioplasty was performed regularly at the time of the rotator cuff repair, though the procedure is now falling out of favor somewhat thanks to the works of Frederick Matsen, MD at the University of Washington.
In general, three approaches are available for surgical repair. These include :
- arthroscopic repair
- mini-open repair
- open surgical repair
A small incision, typically 4 cm to 6 cm, is utilized for the mini-open repair. A traditional open surgical incision is often required if the tear is large or complex or if additional reconstruction such as a tendon transfer has to be done.
The orthopaedist will determine an appropriate, individual rehabilitation program for each patient based on the findings during surgery. A strong commitment from the patient to the rehabilitation program is critical to achieving a good surgical outcome.