More and more orthopedic surgeons are finding that treatment depends on an accurate diagnosis of the problem. In this review of superior labral anterior posterior (SLAP) injuries of the shoulder, the accuracy of clinical tests is reported. The authors tell us which tests to use and what the test results mean.
SLAP injuries refer to a tear along the top (front and back) of the labrum. The labrum is a rim of fibrous cartilage around the shoulder socket. It provides depth and stability to the socket.
Seventeen studies over a 10-year period of time were included in this systematic review. The authors compared the sensitivity, specificity, and likelihood ratios for dozens of tests used in the evaluation of shoulder pain and problems.
Sensitivity tells us how good the test is in identifying patients with a SLAP injury. Specificity tells us how good the test is in identifying patients who do not have a SLAP injury. Both of these measurements are used to calculate the likelihood ratios.
These ratios refer to how much more likely (or unlikely) a positive (or negative) test is to be found in patients with the condition compared to people without the problem. These ratios are very useful when looking at the diagnostic accuracy of clinical tests.
After carefully assessing sensitivity, specificity, and ratios for all these tests, there wasn’t one that was good enough to detect the presence (or absence) of a SLAP tear. Tests with the highest levels of accuracy included active compression, compression rotation, biceps load (two separate tests), and the crank test.
More studies are needed to identify which test is best for different types of SLAP lesions. Some tests may be better than others for specific types of SLAP injuries (e.g., falling on an outstretched hand versus overhead throwing injuries). And it may turn out that a combination of tests works best for one injury over another.
For now, it is important that examiners agree on what is a positive or negative result for each test. This will help improve the validity and accuracy of tests.