Comparative digital study using four methods of measurements of the tibial distal anatomical axes for determining the anatomical-mechanical angle in dogs with cranial cruciate ligament rupture

This study evaluates the amplitude of the anatomical-mechanical angle (AMA-angle) using 4 measuring methods of the tibial distal anatomical axes (DAA) previously described, comparing the literature results to determine if there are significant differences in patients with cranial cruciate ligament (CrCL) rupture. This study was comprised of 30 tibiae (29 dogs), including 1 bilateral case. A retrospective study was selected for this research. DAA measurements were performed on all surgically confirmed cases of canine CrCL rupture at Hospital Veterinário de Especialidades Bruselas from 2019 to 2022. Four different published methods (identified by surname of the corresponding author of the original publication) were compared. Tibial measurements were made using Veterinary Preoperative Orthopedic Planning Pro software (https://vpop-pro.com/) on mediolateral radiographic projections obtained from a digital database. The mean (range) in the DAA method conducted by Hulse obtained a AMA-angle of 5.4° (3.3 to 8.1°), 3.0° (0 to 5.8°) for Osmond et al, 3.2° (0.9 to 6°) for Miles, and 5.9° (2.4 to 8.8°) for Tudury. Differences among the means of the AMA-angle of the authors methods were found with a statistical difference (P < .05), except between Osmond and Miles. The mean AMA-angle with the Osmond method concurred with previous study results that determined the magnitude using the same measurement method of DAA in patients with CrCL rupture. The AMA-angle magnitude has been associated with higher sensitivity and specificity for predicting the development of CrCL rupture compared to other anatomical factors evaluated; therefore, future comparisons with different methods of measurement of the DAA between healthy and affected patients are recommended to determine whether any of them can increase the percentage value as a predictive factor for the occurrence of this condition.