Dr. Sterett Talks Rotator Cuff Tears and Shoulder Impingement
Shoulder Anatomy
The shoulder joint includes the ball (humeral head - at the end of the upper arm) and the socket (the glenoid). There are 4 major muscles that connect the humeral head to the glenoid of the scapula called the "rotator cuff”. These muscles start on the scapula, or wing bone, but their tendons (which connect muscle to bone) attach to the humeral head, and allow us to raise and rotate our shoulder.
What is Rotator Cuff Impingement?
Rotator cuff impingement occurs when the rotator cuff tendons are compressed or worn.
Normally, the rotator cuff glides smoothly between the undersurface of a bone called the acromion and the humeral head. With overhead activity, the acromion can “impinge” on the rotator cuff creating a condition where the tendons become swollen - tendonitis.
Bursitis, Tendonitis, or Rotator Cuff Tear?
When talking about the rotator cuff, bursitis and tendonitis can be used interchangeably. This refers to inflammation without the tearing of the tendon.
The severity of the inflammatory response depends on several factors. In the worst case scenerio, the cuff tendons will actually be torn.
What Causes Rotator Cuff Tendonitis?
When the normal gliding function is compromised repeatedly or suddenly, this may lead to rotator cuff impingement. Common causes include weakening within the tendon due to aging, the formation of bone spurs, or inflammatory tissue formation, and traumatic injuries.
Note the cuff may be “pinched” by the bone (acromion). Overuse activities that can lead to rotator cuff impingement are commonly seen in tennis players, swimmers, and pitchers. While performing overhead activities the acromion may act like a “knife-edge” and cut or “impinge” on the rotator cuff tendons. The big differentiation is whether this “knife-edge” actually cuts through the tendons or just bruises the cuff.
How are Rotator Cuff Tears and Impingement Diagnosed?
Shoulder impingement can usually be diagnosed with a physical exam. Patients dealing with shoulder impingement often complain of pain in the shoulder. The pain will be more pronounced with overhead activity, and sometimes it will be so severe that patients will awake at night because of the pain.
Physical examination of the shoulder will usually reproduce the symptoms and confirm the diagnosis. On the other hand Patients with Rotator Cuff tears of deal with "weakness." An injection of local anesthetic helps us make a diagnosis of impingement vs a rotator cuff tear. We call this an “Impingement Test”. X-rays are also helpful in evaluating the narrowing of the area under the acromion. MRI (magnetic resonance imaging), can give us a clear look at the rotator cuff and is often used to help differentiate impingement from a tear.
How is This Shoulder Impingement Treated?
The first step in treating shoulder impingement is eliminating the cause or contributing factor. This could mean avoiding certain actives that involve using the rotator cuff. Over-the-counter anti-inflammatory medications can help manage pain, swelling, and inflammatory bursitis. There are some excellent home exercise programs available for conditioning the shoulder muscles, so ask your physical therapist.
Occasionally, an injection of a steroid anti-inflammatory may be required to treat this condition. The mainstay of treatment involves exercises to restore normal flexibility and strength to the shoulder girdle, including strengthening both the rotator cuff muscles and the muscles responsible for the normal movement of the shoulder blade.
What Happens if Rehab for Shoulder Impingement Doesn’t Work?
While conservative methods are often enough to treat your shoulder impingement, we may recommend surgery if symptoms persist. Shoulder impingement surgery typically involves shaving down the undersurface of the bone that is causing the impingement. This is done with an arthroscopic technique.
The outcome is favorable in about 90% of the cases. When we have a rotator cuff tear, surgery is typically recommended in the active individual. Unfortunately, rotator cuff tears cannot heal on their own. The natural history of a torn cuff is often one of gradually increasing size, occasionally to the point of being not repairable. While the pain of a cuff tear can often be treated conservatively, repair before the tear becomes too large is typically preferable.
