impingement syndrome and rotator cuff tendonitis/rotator cuff tears of the shoulder
The rotator cuff is a group of four tendons which fuse together and surround the front, back, and top of the shoulder joint like a cuff on shirt sleeve. These tendons are connected individually to short, but very important muscles that originate from the scapula or "shoulder blade". When these muscles contract, they pull on the rotator cuff tendons, causing the shoulder to rotate upward, inward or outward; hence, the name "rotator cuff".
The uppermost tendon of the rotator cuff is known as the supraspinatus tendon, and it passes beneath the bone on the top of the shoulder, called the acromion. In some people, the space between the undersurface of the acromion and the top of the humeral head is quite narrow. The rotator cuff tendon and the adherent bursa, or lubricating tissue, can therefore be pinched when the arm is raised into a forward position or out to the side. With repetitive impingement, the tendons and bursa can become inflamed and swollen and cause the painful situation known as "chronic impingement syndrome."
When the rotator cuff tendon and its overlying bursa become inflamed and swollen, the tendon may begin to break down near its attachment on the humerus bone. With continued impingement, the tendon is progressively damaged, and finally, the tendon may tear completely away from the bone.
There are many factors that may predispose one person to impingement and rotator cuff problems. The most common factor is related to the shape and thickness of the acromion (the bone forming the roof of the shoulder). If the acromion has a bone spur on the front edge, it is more likely to impinge on the rotator cuff when the arm is elevated upwards in a forward manner. Activities which involve forward elevation of the arm may put an individual at higher risk for rotator cuff injury. Sometimes the muscles of the shoulder may become imbalanced by injury or atrophy, and imbalance can cause the shoulder to move forward with certain activities which again may cause impingement.
Rotator cuff problems can be caused by other factors aside from impingement. For example, in young, athletic individuals, injury to the rotator cuff can occur with repetitive throwing, overhead racquet sports, or swimming. This type of injury results from repetitive stretching of the rotator cuff during the follow-through phase of the activity. The tear that occurs is not caused by impingement, but more by a joint imbalance. This may be associated with looseness (or instability) in the front of the shoulder caused by a weakness in the supporting ligaments.
Finally, rotator cuff damage can occur from direct trauma, such as a fall on the outstretched arm or sometimes from a fall directly upon the shoulder itself.
For people with impingement and rotator cuff related pain, the common complaint is aching located in the top and front of the shoulder, or on the outer side of the upper arm (deltoid area). The pain is usually increased when the arm is lifted to the overhead position and oftentimes when reaching behind. Frequently, the pain seems to be worse at night, and often interrupts sleep. Depending on the severity of the injury, there may also be weakness in the arm and, with some complete rotator cuff tears, the arm cannot be lifted in the forward or outward direction at all.
The diagnosis of rotator cuff tendon disease is made by obtaining a careful history from the patient, a thorough physical examination by the orthopedist, and review of X-rays of the shoulder to visualize the bony anatomy, specifically looking for an acromial spur. Atrophy, or loss of muscle tissue, may be present, along with muscle weakness, particularly if the rotator cuff tendons are injured. In addition, there are several impingement tests that can be performed on physical examination which can suggest that impingement syndrome is involved. An MRI (magnetic resonance imaging) scan (usually administered with a contrast dye injected into the joint at the time of the scan to better visualize the anatomy of the shoulder) frequently gives the final proof of the status of the rotator cuff tendon. Although none of these tests is guaranteed to be 100% accurate, most rotator cuff injuries can be diagnosed using a combination of these various tests.
The initial treatment of impingement syndrome is nearly always conservative and non-surgical in nature. For minor impingement and/or rotator cuff tendinitis, a period of rest coupled with medicines taken by mouth, and physical therapy will frequently decrease the inflammation and usually restore the tone to the atrophied muscles. Activities causing the pain should be slowly resumed only when the pain is gone. Application of ice to the tender area three or four times a day for 15 minutes is also helpful. If these conservative measures do not produce the desired result, then oftentimes a cortisone injection into the painful bursal space above the rotator cuff tendon is helpful in relieving swelling and inflammation.
In cases in which these treatment modalities are ineffective, it is frequently because there is a thickened acromion or acromial bone spur causing impingement. In such cases, surgery consisting of arthroscopy of the shoulder can be performed to remove this thickened acromial spur with a dental-like burr and, at the same time, to remove any fraying to the rotator cuff tendon and any scarred bursal tissue. This procedure is nearly always performed on an outpatient basis. In most cases, a pain pump is inserted during the time of surgery which affords excellent postoperative pain relief for 2 days, at which time the pain pump catheter is easily and painlessly removed in the office at the first post-op check-up with the doctor 48 hours after surgery. Immediately after the surgery, patients are placed in sling for a couple of days and then usually receive about 6-8 weeks of physical therapy. After such a treatment regimen, nearly all patients will obtain complete relief of their pre-operative impingement symptoms and also not have to worry about any recurrent symptoms or progressive rotator cuff injury.
For those patients who have a compete tear of a tendon involving the rotator cuff, the tendon must oftentimes be repaired using surgical techniques. The choice of surgery, of course, depends on the severity of the symptoms, the health of the patient, and the functional requirements for that shoulder. In young working individuals, repair of the tendon is most often recommended. In some older individuals who do not require significant overhead lifting ability, surgical repair may not be as important. If chronic pain and disability are present at any age, consideration for repair of the rotator cuff should be given. Today, we are able to repair nearly all rotator cuff tears via arthroscopic surgery that requires only very small incisions.
In some situations, the bursa overlying the rotator cuff may form a patch to close the defect in the tendon. Although this is not true tendon healing, it may decrease the pain to an acceptable level. If the tendon edges become fragmented and severely worn, and the muscle contracts and atrophies, repair at that point may not be possible. Sometimes in this situation, the only beneficial surgical procedure would be an arthroscopic operation to remove bone spurs and fragments of torn tissue that catch when the arm is rotated. This certainly will not restore normal power or strength to the shoulder, but will often relieve pain.
From a surgical perspective, the arthroscope is extremely helpful when repairing rotator cuff tendons. The arthroscope allows visualization of the interior of the joint to facilitate trimming and removal of fragments of a torn rotator cuff tendon and sometimes of a torn or frayed biceps tendon. The next step utilizes the arthroscope to visualize the spur and thickened ligament beneath the acromial bone, which are then removed with miniature cutting and grinding instruments. If it is necessary to suture a rotator cuff tear, this can now be performed in the great majority of cases through the arthroscope using special instuments that allow the tendon to be directly sutured to itself or sometimes by placing suture anchors in the bone and then tying the torn tendon back down to the bone from which it detached. In a small minority of patients, a mini-open procedure through a 2 inch scar may be necessary for those tears that cannot be repaired through the arthroscope. As in the arthroscopic surgery performed for impingement syndrome, this procedure is almost always done on an outpatient basis.
For the more minor arthroscopic procedure for impingement, the shoulder is placed in a simple sling. For the more complicated rotator cuff repairs, the shoulder is supported by a shoulder immobilizer. The shoulder immobilizer is worn for a period of about 4-6 weeks to allow the repaired rotator cuff tendon to heal; however, during this time, the immobilizer is periodically removed to allow for exercise of the elbow, wrist, and hand as well as to perform very gentle "passive" range of motion exercises for the shoulder.
In minor tendinitis and impingement syndrome, overall the recovery program after surgery takes approximately two to three months. For those rotator cuff tears that have been surgically repaired, however, it may take six months or more before the atrophied muscles can resume their function and the range of motion of the arm is restored. Frequently, pain relief is much quicker, and return to daily activities is often possible by two to three months.
In the young, healthy person with a minor rotator cuff impingement, surgery is predictably successful. As the injury becomes more severe, such as with a large bone spur and fragmentation/tearing of the tendon, a perfect result cannot always be expected. Since it is necessary to trim back the unhealthy tendon before reattaching it to the bone, a decreased range of motion of the shoulder will sometimes result. Despite this, pain relief and return of strength are usually well worth the minor decreased mobility. The final outcome often depends on the willingness and ability of an individual patient to work on their postoperative physical therapy program.
The information contained above is for educational purposes only. If you have
any questions relating to this or to any other orthopedic conditions, please consult
a board-certified orthopedic surgeon.