CT-based assessment of the stress state of dog spines

An urgent task of biomechanics is the study of the influence of external loads on the human musculoskeletal system, one of the main elements of which is the vertebral column. In this case, research involves considering the spine as a complex system consisting of vertebrae and the intervertebral discs that articulate them. At the moment, there are many works devoted to determining the causes of various abnormalities in the tissue fibers between the vertebrae, which leads to the development of discopathy. Dogs are the most susceptible to such changes due to their genetic predisposition. Thus, in this work, studies were carried out on the cervical spine of three animals: Yorkshire Terrier, Russian Toy Terrier and half-breed. During the work, numerical modeling of samples was performed using computed tomography data. Computational experiments were carried out using the finite element method and made it possible to determine the stress state taking into account the distribution of the mechanical properties of the material. The tests corresponded to longitudinal compression of the samples. Based on the results obtained, the compressive stress field was determined, the reliability of the values was assessed according to the energy error, and the von Mises stress intensity and the rigidity of the resulting structure were calculated. Analysis of the results showed that the highest stress values are achieved between the vertebrae of the border sections of the cervical spine. On average, a sample of the Yorkshire Terrier breed is predisposed to experience greater stress compared to the results of other dogs in the experimental group. The highest rigidity corresponded to half-breed: twice as much as the average value for dwarf breeds. The distribution of the energy error showed that the areas with the highest values correspond to finite elements at the boundary between different phases of the medium. Thus, the results obtained in the framework of the study make it possible to establish the nature of the distribution of the stress state in the intervertebral discs, as well as to identify the strength indicators of the vertebral columns, taking into account the mechanical properties of various biological tissues.