Currently, the clinical tests we use to detect early meniscal lesions have variable diagnostic accuracy. A few years ago, the Journal of Bone and Joint Surgery published a study which examined the diagnostic accuracy of a new, functional meniscal test, The Thessaly’s test. The results of this study indicated that the Thessaly’s test, performed in 20 degrees of knee flexion, had a diagnostic accuracy of 94% in detection of medial meniscal tears and 96% in detection of lateral meniscal tears. Other, more traditional tests, performed in this study, had much lower detection rates.
How to perform: The patient stands on a single leg (the effected leg) with their knee bent to 20 degrees. The examiner helps support them with UE support. The patient then rotates his/her knee internally and externally. Complaints of pain, knee locking or catching is considered a + test.
Theory of how it works: With this maneuver, the meniscal tear is subjected to excessive loading conditions.
Medial Menscus Detection Sensitivity: 89% Specificity: 92% Accuracy: 94%
Lateral Meniscus Detection Sensitivity: 97% Specificity: 96% Accuracy: 96%
(Note: This test can also be performed in 5 degrees of knee flexion with lower diagnostic accuracy)
Karachalios T, Hantes M, et al. Diagnostic accuracy of a new clinic test (the Thessalay test) for early detection of meniscal test. Journal of Bone and Joint Surgery 2005; 87: 955-962.