Patellar tendon angle
Patellar tendon angle
- Acronym: PTA
Definition
The patellar tendon angle is a measurement used to assess the anatomy of the tibia and its modification in predisposed dogs or dogs at risk for cranial cruciate ligament rupture. It is determined from a mediolateral radiograph of the tibial. The X-ray beam is centred at the stifle joint, with an angle of extension of 135+/-5°. The mediolateral projection is considered acceptable when the femoral condyles are superimposed.
The patellar tendon angle is measured as the angle between the proximal tibial joint orientation line (tibial plateau) and a line drawn from the cranial most aspect of the patella to the cranial most aspect of the tibial tuberosity.
The following values have been published for the patellar tendon angle:
Labrador Retrievers: 106.9 +/- 3.9° (Vedrine et al. 2013)
Large breed dogs: 96° (70-116) (Schwandt et al. 2006)
Yorkshire Terriers: 103.7 +/- 6.5° (Vedrine et al. 2013)
Small breed dogs: 103.7+/-6.2° (Witte 2015)
References
Vedrine B, Guillemot A, Fontaine D, Ragetly GR, Etchepareborde S. Comparative anatomy of the proximal tibia in healthy Labrador Retrievers and Yorkshire Terriers. Vet Comp Orthop Traumatol. 2013;26(4):266-70. doi: 10.3415/VCOT-12-02-0018. Epub 2013 Apr 24.
Witte PG. Tibial anatomy in normal small breed dogs including anisometry of various extracapsular stabilizing suture attachment sites. Vet Comp Orthop Traumatol. 2015;28(5):331-8. doi: 10.3415/VCOT-14-12-0186. Epub 2015 Jul 21. PMID: 26195139.
Schwandt CS, Bohorquez-Vanelli A, Tepic S, Hassig M, Dennler R, Vezzoni A, Montavon PM. Angle between the patellar ligament and tibial plateau in dogs with partial rupture of the cranial cruciate ligament. Am J Vet Res. 2006 Nov;67(11):1855-60. doi: 10.2460/ajvr.67.11.1855. PMID: 17078746.
