Anatomy of the Rotator Cuff
The shoulder is the most free-moving joint in the body. It is composed of three bones: the humerus (upper arm), the scapula (shoulder blade), and the clavicle (collar bone). The humerus and scapula form a ball and socket joint, but the socket is very shallow in the shoulder. A good analogy would be a golf ball on a golf tee. This bony anatomy allows free motion but does not give the shoulder inherent stability.
The rotator cuff is made up of four muscles whose tendons come together as a “cuff” to attach on the head of the humerus. The muscles of the rotator cuff are attached to the shoulder blade, and their tendons are attached to the head of the humerus. This serves as an attachment for the upper arm to the shoulder blade and gives stability to the joint and helps keep the ball centered in the socket during motion. They also help coordinate the complex motions of the shoulder with the larger, stronger muscles such as the deltoid and the pectoralis muscles.
There is a fluid sac (bursa) that lies between the rotator cuff and the bone on top of the shoulder. This provides lubrication and helps the shoulder move freely. If the rotator cuff is injured, the bursa may become inflamed and cause pain.
Description of Rotator Cuff Tears
When one or more of the rotator cuff tendons is torn, there is a disruption between the rotator cuff muscle and the head of the humerus. The muscle cannot work efficiently, and a tear usually causes weakness and pain. The supraspinatus muscle is the most commonly torn rotator cuff tendon, but others may be involved as well.
In many cases, torn tendons begin by fraying. As the damage progresses, the tendon can completely tear. This can happen gradually, or can happen suddenly with an injury such as a fall or attempting to lift a heavy object.
There are different types of tears.
- Partial Tear – This type of tear is usually described as a percentage of the tendon thickness involved (25%, 50%, etc.), and does not go all the way through the tendon.
- Full-Thickness Tear – This type of tear is also called a complete tear. Full-thickness tears usually occur at the point where the tendon attaches to the bone of the humerus, but can sometimes occur in the substance of the tendon or at the junction where the muscle fibers transition into tendon fibers. With a full-thickness tear, there is basically a hole in the tendon.
Causes of Rotator Cuff Tears
There are two main causes of rotator cuff tears – acute injury and degeneration.
If you fall down on your outstretched arm or lift something too heavy with a jerking motion, you can tear your rotator cuff. Weightlifting injuries can sometimes cause rotator cuff tears as well. This type of tear can occur in conjunction with other shoulder injuries, such as a broken collarbone or shoulder dislocation.
Most tears are the result of wearing of the tendon that occurs gradually over time. This degeneration naturally occurs with aging. Degenerative tears are more common in the dominant arm. If you have a degenerative tear in one shoulder, there is a greater risk for a future rotator cuff tear in the opposite shoulder – even if you have no pain in that shoulder.
Several factors contribute to degenerative rotator cuff tears.
- Repetitive stress – Repeating the same shoulder motions over and over can stress your rotator cuff muscles and tendons. Sports such as baseball, tennis, rowing, and weightlifting can put you at risk for overuse tears. Many jobs and routine chores can cause overuse tears as well.
- Lack of blood supply – As we age, the blood supply in our rotator cuff tendons decreases. This diminished blood supply impairs the body’s natural ability to repair tendon damage. Over time, this can lead to a full tendon tear.
- Bone spurs – Spurs (overgrowth) often develop on the underside of the acromion and at the end of the clavicle as we age. When we lift our arms, the spurs rub and impinge on the rotator cuff tendons. This condition is called shoulder impingement, and over time can weaken and damage the tendon and make it more likely to tear.
- Age over 40 – Since most rotator cuff tears are caused by the normal wear and tear of aging, older people are at greater risk.
- Jobs requiring repetitive lifting or overhead activities – painters, carpenters, electricians, etc.
- Sports involving throwing or overhead motions – baseball pitchers, tennis players, volleyball hitters, etc.
Although overuse tears caused by sports activity or overhead work also occur in younger people, most tears in young adults are caused by a traumatic injury, like a fall.
The most common symptoms of rotator cuff tears include
- Shoulder pain at rest and especially at night, particularly if lying on the affected shoulder
- Pain when lifting or lowering your arm
- Pain with specific movements (brushing your hair or putting on a jacket for example)
- Weakness when lifting or rotating your arm
- Crepitus or crackling sensation when moving your shoulder in certain positions
- Acute tears, such as from a fall, usually cause intense pain and marked weakness.
- Pain that radiates from the shoulder down the arm
- Muscle pain or spasm in the muscles of the neck and around the shoulder blade
Medical History and Physical Examination
After discussing your symptoms and medical history, your doctor will examine your shoulder, checking for tenderness or deformity of the shoulder. Range of motion and strength in several different planes will also be tested.
Your doctor will check for other problems with your shoulder joint such as arthritis, and likely examine your neck to make sure that the pain is not coming from a pinched nerve.
Tests that may help confirm your diagnosis include
- X-rays – While X-rays by themselves cannot confirm a rotator cuff tear, they are important to evaluate for shoulder or AC joint arthritis, bone spurs that may cause shoulder impingment, elevation of the humerus which can be a sign of a large rotator cuff tear, calcium deposits in the rotator cuff, and to rule out fractures in acute shoulder injuries
- Magnetic resonance imaging (MRI) – This study can better show soft tissues like the rotator cuff tendons, and can show the size and orientation of a rotator cuff tear. It can also help determine the age and repair potential of a tear by looking at the atrophy and degeneration of the rotator cuff muscles.
- CT arthrogram – While not as good as MRI in evaluating the rotator cuff, this test is useful in patients who cannot have an MRI (for example, patients with pacemakers or severe claustrophobia)
Treatment Options for Rotator Cuff Injuries
The goal of any treatment is to reduce pain and restore function. There are several treatment options for rotator cuff tears, and the treatment is individualized for every person. Your doctor will consider your age, activity level, general health, and the type of tear you have in developing a treatment strategy.
Non-surgical Treatment of Rotator Cuff Tears
Since rotator cuffs tears do not have to be fixed immediately, a trial of non-operative treatment may be appropriate for most tears. In about 50% of patients, nonsurgical treatment can relieve pain and improve function in the shoulder. Shoulder strength, however, does not usually improve without surgery.
Nonsurgical treatment options include
- Rest – Your doctor may suggest rest and limiting overhead activities. A sling may be used for a short time.
- Activity modification – Avoid activities that cause shoulder pain.
- Non-steroidal anti-inflammatory medication – Over-the-counter drugs like ibuprofen and naproxen, or prescription anti-inflammatory medication can reduce pain and swelling.
- Strengthening exercises and physical therapy – Specific exercises will restore movement and strengthen your shoulder. Your exercise program will include stretches to improve flexibility and range of motion. Strengthening the muscles that support your shoulder can relieve pain and prevent further injury.
- Steroid injection – If rest, medications, and physical therapy do not relieve your pain, an injection of a local anesthetic and a cortisone preparation may be helpful. Cortisone is a very effective anti-inflammatory medicine.
The disadvantages of nonsurgical treatment are:
- No improvements in strength
- Size of tear may increase over time
- Activities may need to be limited
Surgical Treatment of Rotator Cuff Tears
Your doctor may recommend surgery if your pain does not improve with nonsurgical methods. In general, partial tears respond better to non-surgical management and full-thickness tears respond better to surgical treatment. Continued pain is the main indication for surgery. If you are very active and use your arms for overhead work or sports, your doctor may also suggest surgery.
Other surgical indications include:
- Pain that has lasted 6 to 12 months
- Large cuff tear (more than 3 cm)
- Significant weakness and loss of function in your shoulder
- Tear caused by a recent, acute injury
Rotator Cuff Tears: Surgical Treatment Options
Surgery to repair a torn rotator cuff most often involves re-attaching the tendon to the head of humerus (upper arm bone). This is usually accomplished arthroscopically with devices called suture anchors that fix the tendon to the bone and allow the body to heal the tear. A partial tear, especially those comprising less than 50% of the tendon, may need only a trimming or smoothing procedure called a debridement. If large bone spurs are present that cause impingement, these are often removed as well as part of the procedure to prevent re-injury to the repaired tendon. Most of these procedures can be done with minimally invasive techniques that can be performed on an outpatient basis.
Complications of Surgery
The most common complications of rotator cuff surgery include
- Permanent shoulder stiffness
- Anesthesia complications
- Sometimes lengthy recovery time
Rehabilitation plays an important role in regaining your shoulder function after a rotator cuff repair. A structured physical therapy program will help you regain shoulder motion and strength. Therapy will progress in stages following your surgery.
At first, the repair needs to be protected while the tendon heals. You will most likely use a sling and avoid using your arm for the first 2 to 4 weeks. How long you require a sling depends upon the size of your tear and the type of repair.
Once your surgeon decides it is safe for you to begin, a therapist will help you with passive exercises to improve range of motion in your shoulder. With passive exercise, your therapist supports your arm and moves it in different positions. In most cases, passive exercise is begun within the first 2 to 4 weeks after surgery.
After 4 to 6 weeks, you will begin active exercises without the help of your therapist. Moving your muscles on your own will gradually increase your strength and improve your arm control. At around 8 to 12 weeks, you will begin a strengthening exercise program. Eventually, you will be transitioned to a home exercise program that you can do on your own.
Expect a complete recovery to take several months. Most patients have a functional range of motion and adequate strength by 4 to 6 months after surgery. Although it is a slow and sometimes frustrating process, your commitment to rehabilitation is key to a successful outcome.
- If I have a rotator cuff tear and keep using it, will this cause further damage?
A rotator cuff tear can extend or get larger over time. This can occur with repetitive use or a re-injury. Acute pain and weakness following a minor injury likely represents extension of an existing tear. If you know you have a rotator cuff tear, then worsening pain and decreasing strength may mean the tear is getting larger.
- When should I see a doctor for a rotator cuff tear?
If you suspect you have a rotator cuff tear, it is best to see your orthopaedic surgeon. If the doctor also suspects a tear based on history and physical exam, then a diagnostic study such as MRI may be ordered to confirm the diagnosis. Early diagnosis and treatment of a rotator cuff tear may prevent symptoms such as loss of strength and loss of motion.
- Can a rotator cuff tear heal without surgery?
The goals of treatment are to relieve pain and restore strength to the involved shoulder. Many rotator cuff tears can be treated non-surgically to alleviate symptoms. Even though most tears cannot heal on their own, satisfactory function can sometimes be achieved without surgery.
- How long will my rehab be following rotator cuff surgery?
It depends on the size and severity of the tear. A partial tear that only needs debridement and removal of a bone spur may only require 3-4 weeks of rehab before resuming normal activities. A complete tear that needs fixation usually requires 3-4 months of rehab before any heavy lifting, especially overhead lifting, will be allowed.
- Can all rotator cuff tears be repaired surgically?
Some large tears can be difficult, even impossible, to repair. These are usually chronic tears in which the tendon has retracted, and the muscle attached has atrophied and has become infiltrated with fat. This can be seen on MRI, and if the muscles are already infiltrated with fat then the outcomes of repair are much poorer. Some large, chronic tears that are associated with concurrent arthritis of the shoulder are better treated with special shoulder replacement techniques rather than rotator cuff repair.
If you have more questions, please call my office at 502-394-6341.