title: Assessing torsion of the medial cortex of the canine tibia using computed tomography multiplanar reconstruction.
abstract: OBJECTIVE
  To describe a protocol for the measurement of tibial rotational alignment using CT multiplanar reconstructions. To establish the feasibility of producing general guidelines for the amount of torsional contouring to apply to a bone plate applied to the medial aspect of the tibia during repair of a non-reducible tibial fracture.
  
  
  METHODS
  CT scans of the pelvic limbs of 15 chondrodystrophic and 34 non-chondrodystrophic dogs were studied. Medial tibial cortex torsion angle and distal medial tibial cortex angle were determined from CT multiplanar reconstructions. Medial plate application was simulated using a plate contoured to the group mean medial tibial cortex torsion angle and post-simulation tibial rotational alignment was assessed.
  
  
  RESULTS
  Mean medial tibial cortex torsion angles were 23° (chondrodystrophic) and 26° (non-chondrodystrophic). Following simulated plate application the change in medial tibial cortex torsion was less than 10° in 73% of chondrodystrophic and 93% of non-chondrodystrophic tibias. In total, 93% of chondrodystrophic and 97% of non-chondrodystrophic tibias had post-simulation distal medial tibial cortex angle less than 10° from the group mean pre-simulation distal medial tibial cortex angle.
  
  
  CONCLUSIONS
  Medial tibial cortex torsion and tibial rotational alignment can be measured using the protocol described in this study. 26° of internal torsional tibial plate pre-contouring may be appropriate for non-chondrodystrophic dogs, but further clinical validation is required.
authors.affiliation: Anderson Abercromby Veterinary Referrals, Ockley, Surrey, RH5 5RR.
authors.forename: Khadije
authors.initials: K
authors.lastname: Hette
authors.affiliation: Anderson Abercromby Veterinary Referrals, Ockley, Surrey, RH5 5RR.
authors.forename: A A
authors.initials: AA
authors.lastname: Anderson
authors.affiliation: Eastcott Referrals, Dorcan Way, Swindon, SN3 3FR.
authors.forename: D M
authors.initials: DM
authors.lastname: Barnes
mesh_terms: D000818:Animals; D004285:Dogs / Q000033:anatomy & histology / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D008297:Male; D013977:Tibia / Q000000981:diagnostic imaging / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000662:veterinary*; D054159:Torsion, Mechanical