Medidas de translação cranial da tíbia para diagnóstico radiográfico da ruptura do ligamento cruzado cranial em cães

Abstract

This study is divided into two chapters: the first deals with a brief general introduction and theoretical reference regarding the rupture of the cranial cruciate ligament (CCL) in dogs, with the purpose of justifying the objectives and hypotheses formulated in scientific research. The second chapter is presented as a scientific paper, whose objective was to evaluate the effect of tibial compression on cranial tibial translation measurements in normal dogs and CCL ruptured dogs, and to define specific criteria for radiographic diagnosis of the CCL rupture. Radiographs of 60 dogs were divided into three groups: 20 healthy adult dogs, 20 adult dogs with CCL rupture and 20 healthy puppies. In each dog, two mediolateral radiographic projections of the stifle joint were performed, one in the conventional joint position and the other under joint stress by tibial compression. Five variables were measured in each radiographic projection: tibial translation angle measured by the established method (TTAa) and modified method (TTAb), patellar ligament angle (PLA), patellar ligament insertion angle (PLIA), and linear distance between the points of origin and insertion of the CCL (DPOI). The linear measure DPOI was transformed into the ratio rDPOI (DPOI in the tibial compression divided by the DPOI without tibial compression), which was evaluated for diagnostic purposes. Statistical analysis showed that, in relation to the radiographic positioning, the tibial compression significantly altered in almost all variables in the comparison within the groups. The DPOI and TTAa variables did not show differences between the radiographic positions with and without tibial compression in the group of normal adult dogs, but showed a significant difference in the group of dogs with CCL rupture, and they were considered important parameters for the disease diagnosis. Regarding the analysis of the rDPOI, it was possible to differentiate the dogs with CCL rupture from the healthy dogs, with high specificity and sensitivity. Values of rDPOI above 1.05 were consistent with CCL rupture, allowing the precise radiographic diagnosis of the disease.