"Standardized" spinal cord trauma: biomechanical parameters and lesion volume.

The T5-6 level of the feline spinal cord was traumatized by the weight-dropping technique. The following "400 gm-cm" trauma groups were studied:I) 5gm X 80cm; ii) 10gm X 40cm; III)20gm X 20cm; IV) 40gm X 10cm; and V) 80gm X 5cm. It was found that the lesion volume was different in each of the groups even though all had a "400 gm-cm" injury. In Groups I through IV the deformation velocity, energy and lesion volume were related to the height in a hyperbolic manner. In all groups a linear relationship was noted between lesion volume and impulse while a sigmoid-shaped nonlinear relationship between lesion volume and energy was present. The amount of energy transferred to the spinal cord was dependent upon factors such as mass, height, impounder mass and velocity. Energy absorbed by the spinal cord in Group IV was approximately 100 times that in Group I.