Predicting Size of Subscapularis Tears

One of the four muscle-tendon units of the rotator cuff in the shoulder is the subscapularis muscle. There are four clinical tests doctors can use to find out if the subscapularis is torn and how large the tear is. In this study each test is measured for accuracy.

A new test called the Bear-Hug test is included. In this test the patient places the hand of the painful shoulder on his or her opposite shoulder. The elbow is bent and the fingers are straight. The patient tries to keep the hand in that position while the examiner tries to pull the hand away. An external (outward) rotation force is applied. A positive test occurs when the patient can’t hold the hand in place.

Researchers tested 68 patients with possible rotator cuff tears (RCTs) using three standard tests: the lift-off test, the belly-press test, the Napoleon test, and the new Bear-hug test. Results were compared with final findings on arthroscopic exam.

Here’s what they found:

  • Four out of 10 subscapularis tears weren’t detected at all with any of these four tests
  • The lift-off test activates the lower portion of the subscapularis muscle
  • The belly-press and bear-hug tests activate the upper part of the muscle
  • The lift-off test wasn’t positive until more than 75 per cent of the scapularis was torn
  • The belly-press and bear-hug tests were positive when at least 30 per cent of the muscle/tendon unit was torn
  • The napoleon test was positive when at least 50 per cent of the subscapularis was torn

    Overall the tests were very specific (not positive unless something was torn). Sensitivity (able to actually detect a tear) ranged from 17.6 per cent (lift-off test) to 60 per cent (bear-hug test).

    The authors conclude all tests should be used to increase the chances of finding a tear and estimating its size. Since 40 per cent of subscapularis tears are missed with these tests, the surgeon is advised to check the subscapularis carefully for tears during the arthroscopic exam.