Trokos

Test library › Knee

Thessaly test (20° flexion)

For: Meniscal tear

A tear in a meniscus, one of the two C-shaped cartilage pads between the thigh bone and the shin bone. Can follow a twist or develop with age.

Treat with caution (see below)
Sensitivity75%
Specificity87%
LR+ (positive)5.6
LR− (negative)0.28

Caution: These pooled figures rest on just two studies, one of them the original Karachalios study, and the two disagreed sharply; an independent arthroscopy study (Goossens 2015) found LR+ only 1.4.

Its positive likelihood ratio reaches the usual rule-in threshold, but the book does not count it as a reliable rule-in test.

What the numbers mean

  • Positive result: see the caution above before relying on this result.
  • Negative result: a small shift: a negative result nudges the diagnosis down, but does not exclude it.

Work out what a result means for your patient: probability calculator

Other tests in the library for meniscal tear

Source

Smith BE, Thacker D, Crewesmith A, Hall M. Special tests for assessing meniscal tears within the knee: a systematic review and meta-analysis. Evid Based Med. 2015;20(3):88–97. Journal article · meta-analysis
Also cited: Goossens P, Keijsers E, van Geenen RJ, et al. Validity of the Thessaly Test in Evaluating Meniscal Tears Compared With Arthroscopy: A Diagnostic Accuracy Study. J Orthop Sports Phys Ther. 2015;45(1):18–24. Journal article (DOI)

Figures as they will appear in Rule It In, Rule It Out (Trokos, forthcoming). If a newer or better study changes them, this page changes with the book. Figures last updated from the book on 6 October 2026.

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Rule It In is a free evidence letter for musculoskeletal clinicians: one recent study explained, one examination test with its real numbers. From Trokos, publisher of Rule It In, Rule It Out.