Critically Appraised Topic
During our first clinical internship, in two different outpatient orthopedic clinics, we were able to assist in treating patients with various knee injuries. From total knee replacements to repaired anterior cruciate ligaments, the knee was without a doubt the most commonly injured joint within our clinics. While our patients experienced an array of knee injuries, the most frequently observed and were meniscal tears. Throughout our four week internship, we learned of a variety of physical diagnostic tests available for determining if a meniscal tear is present. However, we are unsatisfied with the accuracy that current research has reported for the commonly used McMurray and Joint Line Tenderness tests. In this critically appraised topic, we wish to assess if the Thessaly Test can improve one’s clinical decision of a meniscal tear by providing relatively high diagnostic accuracy, sensitivity, and specificity values in comparison to a Magnetic Resonance Imaging of the knee, the McMurray Test, and the Joint Line Tenderness Test.
Does the Thessaly test accurately detect meniscal tears in individuals aged 15 to 50 years old in comparison to MRI, the McMurray Test, and the Joint Line Tenderness Test?
Clinical Bottom Line
Based on the results of the outcomes from Karachalios et al., Konan et al., and Harrison et al., the Thessaly test does demonstrate a consistently high accuracy with regards to detecting meniscal tears. While both Karachalios et al. and Harrison et al. reported high sensitivity, specificity, and diagnostic accuracy values for the Thessaly test with 20º knee flexion, Konan et al. conveyed results that demonstrated limitations of the test to accurately predict meniscal tears. According to Karachalios, the Thessaly test with 20º knee flexion provided the highest average sensitivity and specificity values of 89% and 97% respectively for the medial meniscus. Similarly, it provided the highest sensitivity and specificity values of 92% and 96% respectively for the lateral meniscus. Additionally, the test indicated the highest diagnostic accuracy of 94% and 96% for the medial and lateral menisci respectively. Harrison et al also reported high sensitivity, specificity, and diagnostic accuracy values for the Thessaly Test with 20º knee flexion of 90.3%, 97.7%, 88.8% respectively. In light of the results from these two studies, we feel confident in the test’s ability to accurately diagnose meniscal tears in adults with chronic knee symptoms that are consistent with a meniscal injury. Still, more research is necessary regarding the Thessaly test, as indicated by the drastically low sensitivity and diagnostic accuracy values reported by Konan et al. Overall, we feel that based upon overwhelming research and clinical experience, the Thessaly Test with 20º knee flexion is a useful tool for diagnosing meniscal tears.
Although the Thessaly test with 20º knee flexion has a consistently high diagnostic accuracy, we have several concerns regarding its ability to safely predict meniscal tears for the general population. Our first concern involves the neglect of each group of researchers to include patients who were acutely injured. This flaw limits the ability of the results from each study to be extrapolated to the general population. Another primary concern regarding the Thessaly test relates to the stress it places upon the patient’s knee. According to Karachalios, several of the patients experienced aggravated knee symptoms during testing, requiring the use of analgesic tablets and one subject experienced severe knee locking.
We feel that the Thessaly test is accurate in predicting meniscal tears but still further research is needed. Despite our concerns, the Thessaly test is easy, inexpensive, and available. Although MRI and arthroscopic surgery remain as the gold standards for diagnosing meniscal tears, it is important to continue to look for a cheaper and easier method. While we believe that further research is necessary, the Thessaly test should be used to help accurately diagnose meniscal tears prior to receiving an expensive and time consuming MRI.
Peixoto, John and Tarpo, Alexandra, "Diagnostic Accuracy of the Thessaly Test for Predicting Meniscal Tears in Patients aged 15 to 50 as Measured by Sensitivity, Specificity, and Likelihood Ratios" (2012). PT Critically Appraised Topics. 29.