Rotator Cuff Injury
A rotator cuff injury refers to damage sustained by any part of the rotator cuff structure in the shoulder.
A collection of muscles and tendons form the rotator cuff, connecting the humerus (upper arm) to the scapula (shoulder blade). Each of the four muscles of the cuff has an insertion into the scapula, and a tendon that originates in the muscles and attaches to the humerus. The muscles and associated tendons are the supraspinatus, infraspinatus, teres minor, and subscapularis. Together they form a cuff that allows extensive movement of the arm and shoulder while helping to stabilize the shoulder joint.
The rotator cuff can be damaged in different ways. A tendon may be torn, muscle fibers may be stretched or torn, adhesions may form in the joint capsule, causing a frozen shoulder, the bursa (fluid-filled cushion between the tendons and the scapula) may become irritated, or the tendons might be pinched between the humerus and scapula.
Injury to the rotator cuff can range from relatively mild, which will resolve with conservative treatment, to a partial or complete tearing of the muscle that may need surgical repair. Any injury to a muscle or tendon is described as a strain, and is graded according to severity, with stretched fibers designated as Grade I, partial tearing of fibers designated as Grade II, and a complete tear of a muscle or tendon designated as Grade III.
- Overuse: repetitive motions can cause injury. Common examples are throwing a ball, lifting heavy objects, or having a job that involves a lot of overhead work such as painting or carpentry.
- Aging: the normal aging process will cause muscles and tendons to gradually degenerate, making them more vulnerable to injury. Tendons have a poor blood supply, so a fairly mild strain can take a long time to heal.
- Trauma: an accident, falling onto an outstretched arm, or grabbing at something overhead to prevent a fall can result in damage to the rotator cuff. A rotator cuff injury may happen at the same time as another injury such as a dislocated shoulder or a broken collarbone.
- Chronic injury: a previous injury may have caused a structural change in the anatomy of the rotator cuff that affects normal function of the shoulder joint, or causes inflammation (tendinitis). Tendinitis is more common in women between the ages of 35 and 50.
If the injury is acute:
- Sudden and severe pain with sensation of tearing running from the shoulder down the upper arm
- Loss of range of motion
- Sensation of grinding when moving the shoulder
- Loss of use of shoulder joint due to pain and muscle weakness
- Pain, worse at night, that may be severe enough to disrupt sleep
- Increasing loss of use of shoulder due to pain
- Weakness of the shoulder joint
- Increased inability to raise the arm up or out to the side
- Deep ache felt in the shoulder and outer area of upper arm
- Possible tenderness over injured area
- Pain made worse with raising the arm to the side or turning it inwards
In order to assess whether you have an acute or chronic condition, your doctor will ask questions relating to any previous shoulder injuries, as well as the circumstances surrounding your current injury and the symptoms that you are experiencing.
Your doctor will physically examine your shoulder and upper arm, palpating (touching) it for areas of tenderness or deformity. The range of motion of the shoulder joint, as well as its strength, will be assessed, unless a broken bone is suspected. Various tests, each using muscle contractions, may be performed to try to identify which muscle is damaged.
Nearby structures such as the neck may also be examined, to rule out pain referred from another condition.
X-rays, although they normally will not show rotator cuff injury, are often taken to rule out broken bones or arthritis as causes of your symptoms. MRI (magnetic resonance imaging) scans are regularly used for diagnosis of shoulder conditions as they show soft tissues in great detail. CT (computed tomography) scans and ultrasound are other diagnostic techniques that may be employed.
Continuing to use the shoulder if you have a rotator cuff injury may cause the injury to worsen. Early treatment will result in an easier and quicker recovery.
Ice, crushed in a bag and wrapped in a towel, can be applied to the painful area several times a day to help reduce inflammation.
You can use a sling to rest the shoulder, but you should continue to use the shoulder gently and often in order to decrease the risk of the shoulder becoming so stiff that you will difficulty regaining full use of it.
With the approval of your doctor you can take over-the-counter NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen or aspirin. Your doctor may inject a corticosteroid directly into the joint. This usually provides a rapid decrease in inflammation and relief from pain, but can only be administered two or three times a year due to potential side effects.
Physical therapy to increase the range of motion, flexibility and strength of the shoulder will be necessary for a good recovery. Your doctor or physical therapist will develop a graduated exercise program for you.
If conservative (non-surgical) treatment fails after about eight weeks, acute rotator cuff injuries may require surgical repair, depending on the type and severity of the damage. Younger patients with a complete tear, or people whose sporting or occupational needs require repetitive shoulder use, are the usual candidates for surgery.
If you have a chronic rotator cuff injury that failed to respond with conservative treatment, you also may benefit from surgery. You will be referred to an orthopedic surgeon to discuss your options. Surgery can be either open (traditional) or arthroscopic.
The results of your treatment will depend on your age, the severity of the injury and the particular treatment chosen. In general, conservative treatment has a success rate of 40-90%, and surgical repair 94%.