The Caton-Deschamps Index is a measure of the position of the patella relative to the tibia.

caton-deschamps index
It is not always easy to decide the exact points of the lines because the patella is slightly different in shape in each person.

 

Caton-Deschamps Index and patella alta

The index is of value in determining whether or not there is patella alta (high riding kneeap). It is a ratio of the distance between:

  • the lower point of the part of the patella that makes contact with the femur to the top of the tibial plateau
  • the length of the part of the back of the patella that makes contact with the femur 

The normal range is 0.8-1.2. A ratio higher than 1.3 is suggestive of patella alta.

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The unstable patella

A discussion about patellar instability, the factors that may cause the patella to sublux or dislocate, and what can be done about it.

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CLINICAL PUBLICATIONS

Evaluation of patella alta using MRI measurements in adolescents. Yılmaz B, Ozdemir G, Sirin E, Cicek ED, Anıl BS and Bulbun G. Indian J Radiol Imaging. 2017 Apr-Jun; 27(2): 181–186.


See also -


 

eBook on patellar instability

eBook - Factors contributing to an Unstable Patella

An easy-to-read eBook about patella alta and other causes of kneecap instability.