Rotator Cuff Injuries
Disorders of the rotator cuff are a common cause of pain and disability in adults. Close to 2 million people in the United States seek medical attention yearly because of rotator cuff problems. The rotator cuff is a group of 4 muscles that attach around the edge of the "ball" (humeral head) of the shoulder. There is one muscle in the front called the subscapularis. There is one muscle on top called the supraspinatus. There are two muscles in the back called the infraspinatus and teres minor. These muscles surround the ball and help keep it centered in the socket. They also provide assistance with shoulder movement such as lifting the arm overhead and side to side rotation. The rotator cuff muscles originate on the shoulder blade and become tendons as they insert around the humeral head. The tendon portion (shown in white on the image below) is the area most commonly injured. Overlying the tendon is a lubricating sac called a bursa. The bursa helps lubricate the rotator cuff to glide freely under the bony prominence of the shoulder blade called the acromion.
Rotator Cuff Tendinitis, Bursitis and Impingement
One of the most common sources of shoulder pain is inflammation of the rotator cuff tendons. There is often inflammation of the overlying bursa as well. It is usually difficult to distinguish which of these two structures may be producing the inflammatory pain. Therefore, the terms rotator cuff tendinitis and bursitis are used interchangeably. Impingement is a term used to describe narrowing of the space between the rotator cuff and the overlying acromion bone. This narrowed space will produce inflammation in the bursa and rotator cuff.
Rotator cuff tendinitis can occur at any age. In younger athletes, it is usually due to overuse. It is more commonly associated with overhead sports such as swimming, baseball and tennis. Impingement may be present but it is not due to a bony spur developing on the acromion. The narrowing of the space between the acromion and the rotator cuff is a result of upward migration of the humeral head. Weakness in the rotator cuff and laxity of the shoulder ligaments may cause the humeral head to no longer remain centered in the socket. This is called secondary impingement. In middle age adults, tendinitis is often due to repetitive lifting or overhead activities associated with their occupation. It is felt that continued overhead use of the shoulder can cause a bony spur to develop on the underside of the acromion. This can lead to primary impingement as the spur rubs on the underlying bursa and rotator cuff tendon. Primary impingement is the main source of rotator cuff inflammation and bursitis in older adults.
A unique form of tendinitis in the rotator cuff is calcific tendinits. For unclear reasons, the tendon may develop calcific deposits inside the tendon. The calcium has the consistency of toothpaste and is an irritant to the surrounding tendon. It can become fairly large and result in impingement. The shoulder is typically quite painful with all movement.
Rotator Cuff Tears
The rotator cuff can tear from its attachment on the humeral head. A tear is usually produced from either a sudden injury such as a fall on the outstretched arm or from a gradual fraying of the tendon over time. This degenerative process of the tendon fraying and eventually tearing is similar to a rope that starts to wear out over time. The fraying is usually due to a combination of repetitive overhead use of the shoulder, a lack of a good blood supply to the rotator cuff as we get older and the development of a bone spur producing impingement on the tendon. In younger adults, a tear is typically seen from sudden trauma to the shoulder or from repetitive overhead athletics. These tears are usually smaller and the tendon is good quality. In older adults, the effects of aging may cause the tendon tear to be larger, more frayed and have less strength. The supraspinatus tendon on the top of the shoulder is the one most commonly torn. This tendon is in the area associated with impingement. As the tear becomes larger, the infraspinatus may become involved. The teres minor, located further down the back of the shoulder, is rarely torn. The subscapularis tendon in the front may be torn in isolation or as part of a larger tear involving the supraspinatus.
Symptoms of Rotator Cuff Disorders
Rotator cuff pain is typically felt over the side of the upper arm. Many patients grab their upper arm with the cup of their opposite hand to describe the location of their shoulder pain. There is typically pain with overhead movements. At first, there is usually not much discomfort during the day at rest. However, pain at night is a common symptom associated with rotator cuff disorders. Night pain often causes patients to seek treatment. It is felt that laying flat causes the inflammation to increase as the blood pools around the shoulder. Many patients notice improvement with trying to sleep in an upright position such as in a recliner. Weakness may start to develop over time especially if there is a tear. A crackling sensation or crepitance in the shoulder can also develop if the tendon has started to tear or if there is significant fluid accumulation within the bursa.
Treatment of the Rotator Cuff
In most cases of rotator cuff tendinitis and bursitis, the shoulder pain can be alleviated without surgery. In younger patients with secondary impingement, physical therapy is helpful to strengthen and stabilize the shoulder joint. Activity modification to avoid repetitive overhead activities and nonsteroidal anti-inflammatory medications are also beneficial. Steroid injections are rarely needed in these young athletes. In a few instances of more severe tendinitis in this age group, arthroscopic stabilization of the shoulder joint may be required. This will decrease the additional strain on the rotator cuff tendons stabilizing the joint. This would only be attempted if nonsurgical treatment had failed for over 6 months.
Primary impingement tendinitis and bursitis is more commonly seen after age 40. These patients also respond very well to nonsurgical treatments. Even if a large spur has developed, many patients can be treated without surgery. Physical therapy to strengthen the shoulder muscles is often helpful. Steroid ("cortisone") into the bursa frequently provides effective pain relief if medications and exercises are ineffective. As long as the tendon is not torn, I will often inject a shoulder three to four times for bursitis. These injections must be spaced by 3-4 months between each one. If the patient obtains very good relief with each injection but the symptoms continue to recur, an arthroscopic removal of the spur (acromioplasty) and excision of the inflamed bursa is typically helpful. Steroid injections that provide no relief are an indication that the source of the pain is not from an impingement bursitis and other etiologies must be explored.
Calcific deposits in the rotator cuff are also frequently managed without surgery. The treatment is very similar to the noncalcified form of tendinitis except injections directly into the calcific deposit with ultrasound guidance may be of benefit. It is felt that the calcium may eventually be reabsorbed by the body but this may take 2 to 5 years. If the shoulder pain does not respond to n0noperative treatment, arthroscopic removal of the calcium deposit is often helpful. The edges of the affected tendon are debrided and a repair of the partial tendon defect left after the calcium excision is frequently required.
Once the rotator tendon cuff tendon has torn, the success of nonoperative treatment is more variable. It has been reported that approximately 50% of patients will have improved pain and function with nonsurgical treatment of a tear. Rest, activity modification, strengthening exercises with physical therapy and possibly a steroid injection are utilized. However, there will be no significant improvement in strength and the tear size may increase over time. Currently, we are unable to predict which tears will become larger. As the tear increases in size, further weakness will develop and the surgical success for repairing the larger tear diminishes. Many patients who opt for nonsurgical treatment will modify their activities to limit overhead use of the arm. In younger, active patients, surgery is usually recommended. This age group is less likely to modify their activities and more likely to have a progression of the tear size. Elderly patients are more willing to accept the tear and limit their overhead activities as long as the pain can be improved with nonsurgical measures. It is important to discuss these options when presenting the treatment options for each patient.
Almost all rotator cuff tears can now be repaired arthroscopically. Three to four small quarter-inch incisions are made around the shoulder. A small camera about the size of a pencil is inserted into the shoulder joint. The camera displays images of the shoulder on a television monitor. The joint is filled with fluid for distention. The entire shoulder joint, ligaments and tendons are visualized well. Through the other incisions (portals) instruments can be inserted to remove the frayed parts of the tendon, excise the inflamed bursa, burr away the bone spur and then sew the tear back to its attachment. Small screw-like devices called anchors are inserted into the bone. Attached to these anchors are durable sutures that are passed through the torn tendon and securely tied. This will hold the tendon against the bone while it heals. The arthroscopic technique has been demonstrated to reduce pain, infection risk and scarring. Factors that can reduce the likelihood of a successful repair are poor tendon quality usually associated with older age, smoking, and poor compliance with the postoperative instructions for rehabilitation. It is important to choose a surgeon experienced in the management of rotator cuff disorders and arthroscopic techniques to maximize your outcome. This is a techniquely demanding operation especially with larger tears. I prefer to do a double row of anchors and sutures to reattach most tears. This provides a secure, broad reattachment to the bone without overcompressing the tendon and restricting it's blood supply.
Key points in the treatment of rotator cuff disorders:
1. Most patients with rotator cuff pain can be managed without surgery
2. Younger athletes with rotator cuff pain have a secondary impingement. The underlying problem of shoulder laxity and instability must be addressed. Removing a "spur" will not be effective in this group.
3. Older patients may be managed without surgery even if they have developed an impingement spur.
4. Tears of the rotator cuff can be managed nonoperatively but the shoulder will remain weaker and the tear may become larger with time.
5. Symptomatic tears that are acute (traumatic), occur in younger patients, or that have not responded to nonoperative management should be surgically repaired.
6. Arthroscopic repair is a techniquely demanding procedure but can be used to repair most all tears.
7. Experience in treating rotator cuff disorders and arthroscopic repairs is important to maximize results. Dr. Payne has been performing arthroscopic shoulder repairs for 25 years and has extensive experience in treating tears of all sizes.
Location of rotator cuff pain
Double row rotator cuff repair
Note the 2 rows of purple sutures
securing the white rotator cuff.
Arthroscopic acromioplasty as the
bur removes the acromial spur
Arthroscopic image of calcium deposit
expressed from the rotator cuff tendon
(white toothpaste-like material)