Background: Several tests for making the diagnosis of rotator cuff
disease have been described, but their utility for diagnosing bursitis alone,
partial-thickness rotator cuff tears, and full-thickness rotator cuff tears
has not been studied. The hypothesis of this study was that the degree of
severity of rotator cuff disease affects the diagnostic values of the commonly
used clinical tests.
Methods: Eight physical examination tests (the Neer impingement
sign, Hawkins-Kennedy impingement sign, painful arc sign, supraspinatus muscle
strength test, Speed test, cross-body adduction test, drop-arm sign, and
infraspinatus muscle strength test) were evaluated to determine their
diagnostic values, including likelihood ratios and post-test probabilities,
for three degrees of severity in rotator cuff disease: bursitis,
partial-thickness rotator cuff tears, and full-thickness rotator cuff tears. A
forward stepwise logistic regression analysis was used to determine the best
combination of clinical tests for predicting the various grades of impingement
syndrome.
Results: The sensitivity, specificity, positive predictive value,
negative predictive value, and overall accuracy of the eight tests varied
considerably. The combination of the Hawkins-Kennedy impingement sign, the
painful arc sign, and the infraspinatus muscle test yielded the best post-test
probability (95%) for any degree of impingement syndrome. The combination of
the painful arc sign, drop-arm sign, and infraspinatus muscle test produced
the best post-test probability (91%) for full-thickness rotator cuff
tears.
Conclusions: The severity of the impingement syndrome affects the
diagnostic values of the commonly used clinical tests. The variable accuracy
of these tests should be taken into consideration when evaluating patients
with symptoms of rotator cuff disease.
Level of Evidence: Diagnostic Level I. See Instructions
to Authors for a complete description of levels of evidence.