Thessaly test is used to detect lateral or medial meniscal tears of the knee joint. It is based on dynamic reproduction of load transmission in the knee joint under normal or trauma condition.
How do you do the Thessaly test?
- The patient first stands barefoot on the healthy leg, supported by the examiner, who holds the patient’s outstretched hands.
- With the knee flexed 5 degrees, the patient is asked to actively rotate the knee and the whole body externally and internally three times around the flexed foot.
- The procedure is repeated again with 20 degrees of flexion.
- The test is then carried out standing on the affected leg.
What does a positive Thessaly test mean?
Thessaly test is considered positive for a meniscus tear if the patient experiences medial or lateral joint line discomfort / pain or a sense of locking/ catching in the knee.
Is the Thessaly test accurate?
A Retrospective cohort study by Bradley K Harrison 1 to assess the validity of the Thessaly test for detecting meniscal tears of the knee by comparing arthroscopic findings to a clinical examination finding, he found that the Sensitivity & Specificity of the test was:
- Sensitivity: 90.3 %
- Specificity: 97.7 %
Another study by Theofilos Karachalios 2 found that the Thessaly test at 20 degrees of knee flexion had a high diagnostic accuracy rate of 94 % in the detection of tears of the medial meniscus and 96 % in the detection of tears of the lateral meniscus, and it had a low rate of false-positive and false-negative recordings.
A study by B Shekarchi 3 to compare Thessaly Test with Joint Line Tenderness and McMurray Test in the Diagnosis of Meniscal Tears, he conclude that The Thessaly can be used to screen for medial meniscus tears. McMurray and joint-line tenderness should be used for suspected medial meniscus tears. For lateral meniscus, McMurray is appropriate for screening and all the tests are useful in clinic.
The test has a high degree of diagnostic accuracy when carried out at 20 degrees of flexion.
The crescent-shaped lateral and medial menisci, attached on top of the tibial plateaus, lie between the articular cartilage of the femur and the tibia.
The blood supply of the meniscus, which is key to successful meniscal repair, comes from the peri meniscal capsular arteries, which are branches of the lateral, medial, and middle genicular arteries. The outer 25% of the lateral meniscus (with the exception of the posterolateral corner of the lateral meniscus adjacent to the popliteus tendon) and the outer 30% of the medial menisci are vascularized, giving these areas the potential for healing. The remaining inner portions of the menisci are considered avascular. Despite the lack of vascularity to the inner portions, tears involving the avascular zone may heal. This healing capacity may be improved with the addition of a fibrin clot or with such techniques as trephination.
The menisci assist in a number of functions, including:
- load transmission,
- shock absorption,
- joint lubrication and nutrition,
- secondary mechanical stability (particularly the posterior horn of the medial meniscus that blocks anterior translation of the tibia on the femur),
- and the guiding of movements.
- Harrison BK, Abell BE, Gibson TW. The Thessaly test for detection of meniscal tears: validation of a new physical examination technique for primary care medicine. Clin J Sport Med. 2009 Jan;19(1):9-12. doi: 10.1097/ JSM.0b013e31818f1689. PMID: 19124977.
- Karachalios T, Hantes M, Zibis AH, Zachos V, Karantanas AH, Malizos KN. Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears. J Bone Joint Surg Am. 2005 May;87(5):955-62. doi: 10.2106/ JBJS.D.02338. PMID: 15866956.
- Shekarchi B, Panahi A, Raeissadat SA, Maleki N, Nayebabbas S, Farhadi P. Comparison of Thessaly Test with Joint Line Tenderness and McMurray Test in the Diagnosis of Meniscal Tears. Malays Orthop J. 2020 Jul;14(2):94-100. doi: 10.5704/MOJ.2007.018. PMID: 32983383; PMCID: PMC7513660.
- Clinical Tests for the Musculoskeletal System 3rd Edition.
- Sarvdeep S. Dhatt, Sharad Prabhakar – Handbook of Clinical Examination in Orthopedics.
- Campbel’s Operative Orthopaedics 12th edition Book.
- Ronald McRae – Clinical Orthopaedic Examination 6th Edition Book.