• the Thessaly test is a dynamic reproduction of load transmission in the knee joint and is performed at 5° and 20° of flexion
  • the examiner supports the patient by holding his or her outstretched hands
  • the patient then stands flatfooted on the floor on one leg (the leg associated with no knee symptoms is tested first)
  • patient rotates his or her knee and body, internally and externally, three times, whilst keeping the weight-bearing knee in slight flexion (5°) - "doing the twist"
    • the same procedure is carried out with the knee flexed at 20°
  • if a patient has a suspected meniscal tears then s/he may experience medial or lateral joint-line discomfort and may have a sense of locking or catching
  • the theory is, that during the test, the knee with a meniscal tear is subjected to excessive loading conditions and will produce the same symptoms that the patient reported
  • the Thessaly test is always performed first on the normal knee so that the patient may be trained, particularly with respect to how to keep the knee in 5° and then in 20° of flexion and how to recognize, by comparison, a possible positive result in the symptomatic knee

There is evidence that the Thessaly test at 20° of knee flexion has a high sensitivity, specificity, and accuracy for detecting medial and lateral meniscal tears.

Reference:

1. Karachalios T et al. Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears. J Bone Joint Surg Am 2005;87:955-62.