Rotator Cuff Injuries
What is it: The rotator cuff muscles are a group of muscles that help to stabilize the humerus in the glenoid. The rotator cuff muscle group includes the supraspinatus, infraspinatus, subscapularis, and teres minor. Rotator cuff injuries include tendinopathies of any of these muscles, impingement of the rotator cuff muscles between the humerus and acromion and tears that can be either partial or full thickness.
How does it present: Many of the injuries above will present with similar symptoms of shoulder pain that may radiate down the arm. The pain is often worse with any activities that require abduction of the shoulder or extension and internal rotation, such as bringing the arms above the shoulder level, reaching for a wallet from the back pocket or attempting to clasp a bra. Often patients will also complain of pain being worse at night when they are trying to sleep. The injury can present as an overuse injury, such as with athletic activities that involve throwing or repetitive overhead motions, or with activities of daily living such as painting a room or raking a yard. The injury can also present acutely, such as after a fall onto the arm or with a yanking or pulling injury to the arm. Pain is a primary presentation, but weakness and decreased range of motion may also be a complaint, especially in cases of full thickness tears.
Common exam findings: In many of the injuries, you may find decrease range of motion in shoulder abduction, internal and/or external rotation. You may also find pain with these ranges of motion and weakness with resisted strength. In addition you may find a positive Hawkin's Test, Empty Can Test, and Drop Arm Test (with a full thickness tear of the supraspinatus). In some cases you may notice multidirectional instability, which can be tested with the Load and Shift Test and Sulcus Sign Test. Multidirectional instability can contribute to the recurrence of an overuse injury. You will also want to look for any evidence of atrophy of the supraspinatus and infraspinatus muscles along the scapula, as this may indicate a chronic tear of the tendon/muscle unit.
Tests and treatment: X-rays may be considered to evaluate for bony pathology if indicated. Evidence of acromial spurring or Type 2 or 3 acromion seen on x-ray may be indicative of shoulder impingement. In chronic rotator cuff tears there may be a decrease in the space between the humerus and acromion with the humeral head shifted upwards. For evaluation of the rotator cuff, an ultrasound or MRI may be indicated if there is clinical question regarding diagnosis. Partial rotator cuff tears, tendinopanthy, impingement, and multidirectional instability may be treated with physical therapy and avoidance of aggravating activity. A corticosteroid injection into the subacromial bursa may be considered to aid in pain management. Cases resistant to conservative treatment may be referred to orthopedics for consideration of a subacromial decompression. In cases of full thickness tears, referral to orthopedics for repair is indicated unless the patient declines surgery. In this case, physical therapy can be used to aid in maximizing return to function.