Test: Thessaly Test (Knee)

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Background/Purpose

The Thessaly Test was introduced by Karachalios and colleagues in 2005 (Journal of Bone and Joint Surgery) as a dynamic, weight-bearing test for detecting meniscal tears. Traditional meniscal tests such as McMurray's and Apley's are done non-weight-bearing. The Thessaly Test instead reproduces the compressive and rotational loads the knee sees during daily activity by having the patient rotate on a single, slightly flexed leg. This loads the menisci between the femoral condyles and tibial plateau. The original study reported high diagnostic accuracy at 20° of flexion, around 94% for medial and 96% for lateral meniscal tears. Later independent studies have found more modest sensitivity and specificity, so it works best alongside other meniscal tests, joint line palpation, and history rather than on its own. It is useful for evaluating knee pain, mechanical symptoms (locking, catching, giving way), and suspected degenerative or traumatic meniscal injury. It may not be appropriate for patients with acute ligamentous instability, significant effusion, or poor balance.

Procedure

The patient stands barefoot on the leg being tested with the opposite leg lifted off the floor. The clinician stands directly in front of the patient and holds the patient's outstretched hands to support balance without restricting movement.

Test the uninvolved knee first so the patient learns the movement and you have a baseline. With the tested knee flexed to 5°, the patient rotates the knee and body internally and externally three times, keeping the foot planted. The patient then flexes the knee to 20° and repeats the same three internal and external rotations. The 20° position is the primary diagnostic position.

The test is positive if the patient reports medial or lateral joint line discomfort, or a sense of locking or catching, during the rotations. Record which side is involved (medial or lateral), the flexion angle at which symptoms occurred, and whether symptoms were pain, locking, or catching.
Performed: Unilaterally

Dialog

Stand on this leg, bend slightly, and twist side to side 3 times. Tell me if you feel pain, catching, or locking.

Criteria

• No medial or lateral joint line pain during rotation at 5° or 20° of knee flexion.
• No sensation of locking, catching, or giving way during the rotations.
• Patient completes three full internal and external rotations at 20° flexion without stopping or guarding.
• Symptoms are comparable to the uninvolved knee.

Measurement

LOINC Code

Scale/Grading

selection range; grade - LOINC ID
Option - Value option selection range; grade - LOINC IDPass ; Pass - Fail ; Fail -