Caton-Deschamps index (knee)
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 an angle of 30º, although the original study by Caton-Deschamps the bending angles were between 20 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 ration can also be applied to children, but age correction should be applied because patellar ossification begins at its proximal side 1.
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
- 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.