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