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Rotator Cuff Injuries

Anatomy

The term “Rotator Cuff” is used to describe the group of muscles and their tendons in the shoulder that helps control shoulder joint motion. The supraspinatus is at the top of the shoulder, the subscapularis is in front, and the infraspinatus and teres minor are behind the shoulder. These muscles insert or attach to the shoulder bone by way of their tendons. The tendons fuse together giving rise to the term “cuff.”

Above the rotator cuff is a bony projection from the scapula (shoulder blade) called the acromion. The acromion forms the “ceiling” of the shoulder, and joins the clavicle (collarbone) to form the acromioclavicular (a/c) joint. Between the rotator cuff tendons and the acromion is a protective fluid-filled sack called a “bursa". With normal humeral elevation there is some contact between the rotator cuff, the bursa, and the acromion. A healthy and strong rotator cuff holds the shoulder joint down in the socket and minimises any bony contact between the shoulder joint and the acromion.

Pathology

Rotator cuff pathology can be caused by extrinsic (outside) or intrinsic (from within) causes.  Extrinsic examples include a traumatic tear in the tendon(s) from a fall or accident. Overuse injuries from repetitive lifting, pushing, pulling, or throwing are also extrinsic in nature. Intrinsic factors include poor blood supply, normal degeneration with aging, and calcification of the tendon.

Rotator cuff “tendonitis” is the term used to describe irritation of the tendon(s) either from excessive pressure on the acromion or less commonly from intrinsic tendon pathology. Irritation of the adjacent bursa is known as subdeltoid or subacromial “bursitis.” Repetitive overhead activities resulting in irritation of the tendon(s) and bursa from repeated contact with the undersurface of the acromion is called “Impingement Syndrome.”  

Rotator cuff dysfunction is typically a continuum of pathology ranging from tendonitis and bursitis to partial tearing, to a complete tear in one or more of the tendons. Although the earlier stages may resolve with conservative care, actual tearing of the tendon can be more problematic. These tears most commonly occur at the junction between the tendon and the bone. Because this area has a relatively poor blood supply, injury to the tendon here is very unlikely to actually heal. Additionally, the constant resting tension in the muscle-tendon unit, or “muscle tone”, pulls any detached fibers away from the bone, preventing their reattachment. Finally, joint fluid from within the shoulder may seep into the tear gap preventing the normal healing processes from occurring.

Diagnosis

Patients with rotator cuff pathology commonly present with an activity related dull ache in their upper outer arm and shoulder. Above shoulder level activity is usually most difficult. Many people have little to no discomfort with below shoulder level activities such as golf, bowling, gardening, writing or typing, etc. Conversely, tennis, baseball/softball, basketball, swimming, painting, etc. will be more problematic.   

Pain in the shoulder may extend down as far as the elbow, but not usually beyond. Neck pain on the same side may also develop later as well as occipital headaches. Patients may also experience snapping or cracking within the shoulder, pain at night, difficulty lying on the shoulder, and difficulty getting dressed. Late findings include weakness and loss of shoulder motion.

X-rays will not show the rotator cuff, but they will reveal any evidence of arthritis, spurs within the shoulder, loose bodies, fractures from a related fall, abnormal displacement of the humerus out of the glenoid, and congenital (birth) related problems. Therefore, good quality x-rays are a must in the proper evaluation of the shoulder.

Magnetic Resonance Imaging or MRI has allowed visualization of the soft tissues of the body, including the rotator cuff. An MRI can depict tendonitis, partial tearing, and complete tears of the rotator cuff. While an MRI is usually not required to diagnose a torn rotator cuff, it can be very helpful to determine which tendons are torn, how large the tear is, the degree of tendon retraction, the extent of muscle belly atrophy (shrinkage), and any coexisting problems.

Conservative Treatment

Many rotator cuff tears do not require surgery. Physiotherapists at SSM are trained in the rehabilitation of rotator cuff injury. Treatment may include rest, activity modification, nonsteroidal anti-inflammatory medications, and physical therapy. Physiotherapy may include heat, cold, ultrasound, electrical stimulation, massage and other modalities, but the hallmark of an effective rotator cuff rehabilitation program is therapeutic exercise. Stretching of particularly the posterior joint capsule can help the tendency of the humeral head to migrate superiorly toward the acromion with forward elevation. Strengthening of the remaining rotator cuff through resistance exercises can again help contain the humeral head within the glenoid and avoid undue pressure up on the acromion.

In patients who fail to improve with initial conservative therapy, there may be a role for judicious use of corticosteroid (“cortisone”) injection therapy in the bursa above the tendon. Your Physiotherapist can decide whether this therapy is appropriate.

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