What’s the diagnosis?
Rotator cuff tear was suspected because Robert had positive elements of the “rotator cuff triad”—supraspinatus weakness (as indicated by a positive empty can test), external rotation weakness (revealed by the French horn test), and a positive Hawkins impingement test. We ordered diagnostic studies, including plain radiographs, which revealed degenerative changes at the acromioclavicular joint, decreased acromiohumeral interval, and no significant changes at the glenohumeral joint (FIGURE 2), and magnetic resonance imaging (MRI) of the right shoulder. The MRI revealed a large, full-thickness rotator cuff tear of the supraspinatus tendon with retraction. A torn and retracted biceps tendon and AC joint osteoarthritis were also shown, likely causing a mass effect on the supraspinatus. The patient underwent surgery to repair the torn rotator cuff, with excellent results.
FIGURE 2
Chronic right shoulder pain
An AP view of the patient’s right shoulder shows acromioclavicular joint narrowing and degeneration and subtle narrowing of the acromiohumeral interval.
The take-away message: Keep the rotator-cuff triad in mind
Because none of the tests that comprise the triad is specific enough alone to diagnose a rotator cuff tear,15,20,21 Murrell and Walton16 suggested that the 3 tests be considered together for diagnostic purposes. If all 3 are positive, there is a 98% chance of a rotator cuff tear; if 2 tests are positive and the patient is older than 60 years, the findings are suggestive of a tear; and if all 3 tests (plus the drop arm test) are negative, there is less than a 5% chance of a major rotator cuff tear.16
CORRESPONDENCE Nilesh Shah, MD, Summa Center for Sports Health, 20 Olive Street, Suite 201, Akron, OH 44310; ShahN@summahealth.org