Caton-Deschamps index can be measured on a lateral radiograph or sagittal knee CT or MRI reconstructions. For measurement it is considered ideal that the knee is flexed at an angle of 30º, although for the original study by Caton-Deschamps the bending angles were between 20º and 80º.
- A: measure of the distance between the lower pole of the patella and upper limit of the tibia
- B: measure of patellar articular surface
The mathematical operation performed is A / B:
- normal range 0.6-1.3
- patella baja: <0.6
- patella alta: >1.3
Caton-Deschamps ratio can also be applied to children, but age correction should be applied because patellar ossification begins at its proximal side 1.
- 1. Thévenin-Lemoine C, Ferrand M, Courvoisier A, Damsin J-P, Pointe HD le, Vialle R. Is the Caton-Deschamps Index a Valuable Ratio to Investigate Patellar Height in Children? J Bone Joint Surg Am. 2011 Apr 20;93(8):e35.
- 2. Seil R, Müller B, Georg T, Kohn D, Rupp S. Reliability and interobserver variability in radiological patellar height ratios. Knee Surg Sports Traumatol Arthrosc. 2000;8(4):231–6.
- 3. van Duijvenbode D, Stavenuiter M, Burger B, van Dijke C, Spermon J, Hoozemans M. The reliability of four widely used patellar height ratios. Int Orthop. 2016 Mar;40(3):493–7.
- 4. Munch JL, Sullivan JP, Nguyen JT, Mintz D, Green DW, Shubin Stein BE, et al. Patellar Articular Overlap on MRI Is a Simple Alternative to Conventional Measurements of Patellar Height. Orthop J Sports Med. 2016 Jul;4(7):2325967116656328.
- 5. Narkbunnam R, Chareancholvanich K. Effect of patient position on measurement of patellar height ratio. Arch Orthop Trauma Surg. 2015 Aug;135(8):1151–6.
The knee is a complex synovial joint that can be affected by a range of pathologies:
- bone and cartilage
- distal femoral condyle fracture
- tibial plateau fracture (classification)
- patella fracture
avulsion fractures of the knee
- Segond fracture
- reverse Segond fracture
- anterior cruciate ligament avulsion fracture
- posterior cruciate ligament avulsion fracture
- arcuate complex avulsion fracture (arcuate sign)
- biceps femoris avulsion fracture
- iliotibial band avulsion fracture
- semimembranosus tendon avulsion fracture
- Stieda fracture (MCL avulsion fracture)
- patella fracture
- chronic avulsion injuries
- chondromalacia patellae
- osteoarthritis of the knee
- osteochondral defects
- osteochondritis dissecans of the knee
- pattern of bone contusion in knee injuries
- knee fractures
- meniscal lesions
- synovial lesions
- fat pad
- popliteal fossa