Clinical accuracy of McMurray test and Thessaly test in meniscal injuries and their correlation with MRI

Abstract

Background: The meniscus of the knee are vital for load bearing and shock absorption. Meniscal injury are common in young active adults who engaged in athletic activities. Following meniscal injury the presentation may vary from mild joint discomfort to frank locking of the joint. This creates a lot of morbidity to the patient. Various clinical tests are available for examining the integrity of the meniscus. The Thessaly test and McMurray test are very useful and cheap screening tools for identifying patient with suspected meniscal injuries. Before advising any patient presenting with traumatic knee pain for expensive investigations like MRI for suspected meniscus injury, these two clinical tests can serve as useful adjuncts in the management of such patients as not all meniscus tear need invasive treatment. Objectives: To assess the validity of a new clinical test (Thessaly) as a means of diagnosing meniscal tears of the knee by comparing the findings of Thessaly test with those of MRI and /or arthroscopy. Materials and Methods: This cross-sectional study was done between June 2016 to June 2017 at chettinad hospital & research institute on consecutive patients who presented with suspected meniscal injury. These patients were screened for meniscal injuries by performing the McMurray and Thessaly test. Patients with strong clinical suspicion for meniscal tear were then advised MRI of the injured knee. The findings of MRI were then correlated with the clinical findings to measure the diagnostic accuracy. Results: A total of 71 patients were included in the study. The mean of age was 29.77 years with a standard deviation of 7.8. Injury during sports activity accounting for 56.34% of the study sample was the most common mode of injury. The McMurray test was positive in 66.20% and Negative in 33.80% of the study population. The Thessaly test at 5 degree of knee flexion was positive in 63.38% and Negative in 36.62% of the study population. The Thessaly test at 20 degrees of knee flexion was positive in 73.24% and Negative in 26.76% of the study population. Thessaly test in 20 degree flexion is more sensitive than McMurray test for diagnosis of meniscal lesions. Whereas McMurray test has better specificity and better predictive values compared to Thessaly test. Conclusions: Both McMurray test and Thessaly test either singly or combined cannot be used as an alternative to MRI in confirming the diagnosis of meniscal lesions. However, they can be used as an effective screening tool in the identification of patients with meniscal lesions who may benefit from further investigations like MRI.