How to Know If Shoulder Pain Might Be Rotator Cuff Disease
Source: Medscape
A positive painful arc test and a positive external rotation resistance test in a patient with shoulder pain has a high likelihood of being rotator cuff disease (RCD). And a positive lag test (external or internal rotation) likely means a full-thickness rotator cuff tear.
That’s according to a meta-analytic review of relevant studies. Dr. Job Hermans from Erasmus Medical Center, Rotterdam, the Netherlands and colleagues say they did the analysis to identify the most accurate clinical examination findings for RCD.
The studies they included involved patients referred to a specialist (orthopedist, rheumatologist, or sports medicine physician) for evaluation of shoulder pain. As a result, the prevalence of RCD was high – 33% to 81%, compared to a general population prevalence of 2.8% to 15%, they noted in JAMA August 28. Among five studies with level 1-2 quality scores, a positive painful arc test result was the only finding with a positive likelihood ratio (LR) greater than 2.0 for RCD (LR 3.7). A normal painful arc test result had the lowest negative LR (0.36).
Among strength tests, a positive external rotation lag test and internal rotation lag test had the highest positive LRs (7.2 and 5.6) for full-thickness tears.
With an LR of 3.3, a positive drop arm test result “might help identify patients with RCD,” the investigators say, whereas a normal internal rotation lag test result was most accurate for identifying patients without a full-thickness tear (LR 0.04).
There is a lack of data from primary care settings for findings that could be used to diagnose RCD among patients with shoulder pain,” Dr. Hermans and colleagues say.
And they caution, “Because specialists performed all the clinical maneuvers for RCD in each of the included studies with no finding evaluated in more than three studies, the generalizability of the results to a nonreferred population is unknown.”
Also, they say, it’s unclear whether examinations performed by generalist physicians would have the same results as those performed by specialists, because differences may be attributable to the skill of the examiner as well as to the patient populations. Yet, they believe the tests “could be mastered with practice by the generalist physician.”
“The approach we present of pain provocation tests, strength tests, and composite tests provides a framework for thinking about the physical examination findings and for interpreting the results,” the researchers conclude.
For a patient with shoulder pain, they suggest the physician could perform a single pain provocation test (painful arc test), three strength tests (internal rotation lag test, external rotation lag test, and drop arm test), and one composite test (external rotation resistance test).
Using the general population prevalence of RCD, which increases with age, the posterior probability of disease would be 9.6% (for patients older than 30 years) to more than 40% (for patients 70 years and older), the investigators say. Among patients referred to shoulder specialists, the presence of pain during the painful arc test confers a more than 60% probability of disease.
On the other hand, general medical patients with no pain during the painful arc test would have a low probability of RCD (1%-6%). Because of the high probability of disease among patients referred to shoulder specialists, the absence of pain during a painful arc test in a referred patient does not rule out RCD, because the probability could still be as high as 13%, the investigators say. They did not respond to request for comment by press time.