Comparative evaluation of contusion spinal cord injury models from ventral and dorsal approaches in rabbits in an experiment

BACKGROUND: Contemporary experimental models for spinal cord injury studies are mainly based on spinal cord injury in rats and mice. Modeling of experimental spinal cord injuries is generally performed from the dorsal approach, which excludes its injury as a result of compression by the fragments of the fractured vertebral body and significantly restricts the application of the results obtained from clinical practice. AIM: To develop and create contusional spinal cord injury model from the ventral approach with its subsequent comparison with the contusional spinal cord injury model from the dorsal approach. MATERIALS AND METHODS: The study examined 20 female Soviet Chinchilla rabbits weighing 3.5–4.5 kg. The rabbits were subjected to standardized spinal cord injuries from the ventral and dorsal approaches at the LII level. Somatosensory- and motor-evoked potentials, H-reflex, were recorded in all experimental animals before injury, immediately after, and 3 and 8 h after injury. Histological studies were also performed using qualitative and semiquantitative analyses of biopsy samples of damaged areas and assessing the number of dystrophic neurons over time. The results of neurophysiological and histological examinations of the spinal cord in cases of ventral and dorsal trauma were statistically processed. RESULTS: When modeling spinal cord injury from the ventral approach, in comparison with the model from the dorsal approach, more significant damage is detected. As a result of the injury factor, the dysfunction of both neurons at the traumatization level and peripheral neurons below the injury zone was revealed; however, as histological examinations have shown, in contrast to the dorsal approach, mild hemorrhage was observed in the ventral approach. CONCLUSIONS: The results obtained indicate a more significant and strict contusion mechanism of the spinal cord injury model from the ventral approach and the maximum proximity of the resulting model in a clinical situation. In the future, the experimental model of the contusional spinal cord injury in a laboratory animal can be used in chronic experiments.