Radial torsion angle
Radial torsion angle
- Acronym: RTA
Definition
The radial torsion angle is a landmark used to assess angular deformities of the radius and provide guidance for corrections. It is determined from multiplanar reconstructed CT images of the radius.
The radial torsion angle is definied by the intersection of two lines :
- The line tangent to the cranial cortex across the articular fovea of radial head proximally
- The joining line tangent to the medial eminence of the groove of the abductor pollicis longus muscle and the cranial eminence of the ulnar notch, distally
The following mean value have been reported for the radial torsion angle :
- Shih-Tzu : 20.91 +/- 3.00° (Jeong et al. 2020)
- Normal medium to large breed dogs : 3.6 +/- 6.4° (Kroner et al. 2017)
References
Kwan et al (2014). Correction of Biapical Radial Deformities by Use of Bi-Level Hinged Circular External Fixation and Distraction Osteogenesis in 13 Dogs. Veterinary Surgery, 43(3), 316–329. doi:10.1111/j.1532-950X.2014.12114.x
Jeong J et al. (2020) Measurement of Thoracic Limb Joint Reference Angles in Purebred Shih-Tzu Dogs by Computed Tomography. J Vet Clin 37(4):169 doi.org/10.17555/jvc.2020.08.37.4.169
Meola et al. (2008). Validation of a Technique to Assess Radial Torsion in the Presence of Procurvatum and Valgus Deformity Using Computed Tomography: A Cadaveric Study. , 37(6), 525–529. doi:10.1111/j.1532-950x.2008.00399.x
Kroner et al. (2017). Assessment of radial torsion using computed tomography in dogs with and without antebrachial limb deformity. Veterinary Surgery, 46(1), 24–31. doi:10.1111/vsu.12589
