The shoulder joint is the most mobile joint in the body allowing us to create a myriad of motions which help complete everyday mundane tasks like getting a jar off a shelf to throwing a fast ball over 100 mph.  The rotator cuff muscles are integral in helping to produce these motions as well as to help stabilize the shoulder.  However, due to the wide range of motion of the shoulder as well as the demands put on rotator cuff muscles, they are also relatively susceptible to injury.  Over 4 million people seek medical care for their shoulders in the United States each year.  Rotator cuff tears are most common in people over the 30-40 years old.

Biology/Pathophysiology

The rotator cuff is made up of four muscles (Supraspinatus, Infraspinatus, Teres minor, and Subscapularis) in the shoulder that attach from the scapula bone (shoulder blade) to the humerus bone (arm bone).  Individually, these muscles act to move the humerus bone in motions of external rotation, internal rotation, and abduction (movement away from the body).  Collectively, these muscles help to depress the humerus while the Deltoid muscles elevate the arm, as well as to help stabilize the humerus within the joint.

The rotator cuff muscles are positioned between two bones (Acromion and the Greater/Lesser Tuberosities).  This space between the two bones in some people can be quite narrow.  This is important because the rotator cuff muscles can be pinched between these two bones with certain movements.   In some patients, the acromion bone is hooked or curved downwards causing an even narrower space available for the rotator cuff muscles.  Additionally, bone spurs frequently occur on the undersurface of the Acromion which increases the pinching effect even further.

Initially this pinching and rubbing can cause some irritation and inflammation to occur.  At this stage, this is known as Impingement Syndrome (Bursitus and Rotator Cuff Tendonitis are more or less synonymous terms).  If this process continues, this can progress onto a partial rotator cuff tear, and eventually onto a full thickness tear.  Commonly, trauma such as falling can accelerate this process by causing the humerus bone to violently push up against the acromion bone, or the rapidly contracting rotator cuff muscles can contract so hard that it can pull off the bone, especially in those rotator cuff muscles that are already partially torn.  Other common culprits causing this pinching/tearing of the rotator cuff include repetitive overhead activities, heavy lifting, or possibly sleeping on the affected shoulder. 

Adding to the problem, the blood supply to the portion of the rotator cuff that is most at risk is relatively tenuous.  The blood supply is needed to help repair damage that the rotator cuff endures.  The lack of a blood supply predisposes this area to relatively decreased healing potential. 

Patients who have some form of instability of the shoulder are at higher risk for getting rotator cuff problems.  For example, patients who have extra stretchy ligaments (ligamentous laxity) or have torn ligaments, will have increased abnormal motion of the shoulder and thus less stability.  The rotator cuff muscles are at increased risk for two reasons:  First the abnormal motion can cause increasing contact between the two bones causing more pinching of the rotator cuff muscles.  Second, the rotator cuff muscles must act overtime in trying to make up for some of the stability lost by the ligaments.

High-end throwing athletes can get a slightly different form of rotator cuff tears, called internal impingement – please refer to this section for more specifics.

Symptoms

Common symptoms associated with a rotator cuff tear are;

-           Pain - This pain typically occurs on the front or top of the shoulder and can radiate down towards the elbow.  Sometimes this pain can occur mostly in the arm below the shoulder level.  This may be worsened when raising your arm above the shoulder level, behind your back, or when sleeping on it. 

-           Weakness -  Moderate to severe weakness when attempting to lift one’s arm, especially when trying to initiate movement away from your side.

-           Popping, clicking, or grinding sounds with shoulder movement

-           Stiffness-- Decreased range of motion in your shoulder due to weakness, pain, or

   mechanical reasons

Common Diagnostic Techniques:

It is important to give your physician a detailed account of the pain and the actions leading up to the injury.  Your doctor will then perform a comprehensive physical examination.  Special provocative tests (impingement signs) can help define the diagnosis.  Your doctor will test the strength of individual muscles to determine if there is weakness, which can be indicative of a full tear.  Other examination tests may be performed to help rule out other diagnoses.

While the detailed history and physical can lead to the diagnosis most of the times, other tests may aid in the diagnosis.  X-rays are typically ordered to determine among things the shape of the Acromion, and the presence of spurs and arthritis.  An MRI can frequently help to determine the presence and extent of a rotator cuff tear, as well as to rule out other diagnoses.  An ultrasound may be useful in those patients who are not able to have an MRI scan

At times, your doctor may inject a numbing medicine to help narrow the diagnosis as well as to provide more detail to your problem.

Treatment:

Non-Operative:

Non operative treatment is usually appropriate for those patients who are in the early stages of their problem, specifically when they have either impingement syndrome/bursitis, or partial rotator cuff tears.  This may consist of:

-           Relative rest:  You need to stop doing things that can worsen the problem.  No matter what you do on the proactive treatment side, if you don’t stop doing bad things, you will not catch up with the healing process.  A good rule of thumb is to stop doing anything that causes you even a little bit of pain (except for what you may be doing at physical therapy)

-           An extensive physical therapy protocol.  This must be done and followed faithfully.  Yes, this makes a big difference.  The point of the therapy is to promote treatments that help to decrease inflammation as well as to gently and progressively increase the strength of the rotator cuff muscles.  It’s important to note that you may not notice any significant improvement for at least 2-3 weeks.  Do not give up!  This may be required for 6-12 weeks.  Even after you are fully recovered, it is a good idea to continue the exercises you’ve learned in physical therapy indefinitely.  A little prevention can go a long way!

-           Steroid injections can help decrease inflammation and provide pain relief.  Depending on the severity of your symptoms, this may be offered to you initially, or after you have started other nonoperative therapy. 

-           NonSteroidal Anti-Inflammatory Drugs (NSAID’s).  Assuming you can safely take this medication from a medical standpoint, these medications can also decrease inflammation and provide pain relief.  You should check with your primary care doctor as to whether this is a safe option for you. 

Operative:

Operative treatment is needed for most patients with full thickness tears, and for those who have not improved after nonoperative treatment for a minimum of 6 weeks.  Why is surgery necessary for full thickness tears?  The rotator cuff is like a rubber band that is prestretched.  Once it is fully torn, this muscle will tend to retract, keeping the torn ends from touching each other and thus healing together. 

Surgery when indicated should be performed as soon as possible.  The longer the rotator cuff is torn, the more it can retract.  And just like a rubber band, the longer the rotator cuff is retracted, the more friable and scarred in it becomes, and the less likely it can be repaired easily back to its anatomical position.  This then leads to less successful outcomes despite the most skillfully performed surgery.  Also, if the surgery is delayed for a long enough time, the muscle becomes not only atrophied (wastes away), but it also can lose it’s ability to contract (actually starts looking like fat tissue!).

The surgery can be performed through several different methods. 

Arthroscopic repairs

Technology and technique has improved dramatically in the past 10 years to make this technique not only possible, but the preferred method to repair most rotator cuff tears.  This technique is performed through one centimeter incisions through which a video camera about the size of a pencil is inserted to visualize the entire shoulder.  Micro-instruments have been developed to fit into these 1 centimeter incisions that allow us to repair the torn rotator cuff muscles.  This is the most minimally-invasive surgery possible, one that violates the least amount of normal tissue, and yet provides as strong of a repair as any other method.  Because of this minimal invasive technique, the patient usually has the least amount of postoperative pain and usually the least amount of recovery time.

Mini-Open repairs

The mini–open repair combines the use of an arthroscope and a small (approximately 1-2 inches) incision in order to access the torn rotator cuff.  This technique rarely needs to be employed if for some reason the arthroscopic alone method does not provide the optimum treatment. 

Open repair

This technique is more of an older technique developed prior to the widespread use of the arthroscope.  It entails a relatively large incision, and taking down of normal muscles in order to access the rotator cuff muscles.  This technique is now used rarely in modern surgery.

After Surgery

Typically the shoulder is immobilized in a sling for an average of 4 weeks.  Your physical therapy can start after the first few weeks after surgery.  The rehabilitation can be just as important as the surgery, so take it very seriously.  Recovery from shoulder surgery is often a long process.  While the majority of your improvement typically occurs within the first 6 months, you may continue to improve for up to 1-2 years after the surgery.   For specifics of the rehabilitation process, you can get specific protocols from your doctor.

The success rate of surgery depends on a number of factors, many of which are not under your doctor’s control.  For example, the quality of the repair can depend on age (the older you are the more friable the tissue can be), the type of tear (one simple tear versus one that is frayed and torn in multiple planes), the length of time from injury to surgery (the longer you wait, the harder it is to get a good result), etc.

There are risks in everything you do, and rotator cuff surgery is no exception.  Please visit the general surgery risks section information.  Specific to rotator cuff repairs however, there is a very small chance of possible nerve damage, and a possibility that the rotator cuff can re-tear.  This possibility of retearing depends on the quality of the your repair, and the amount of future trauma and damage done to your rotator cuff.