Spinal cord-fragment interactions following burst fracture: an in vitro model

Object. The purpose of the study was to develop an in vitro model of the bone fragment and spinal cord interactions that occur during a burst fracture and further the understanding of how the velocity of the bone fragment and the status of the posterior longitudinal ligament (PLL) affect the deformation of the cord. Methods. An in vitro model was developed such that high-speed video and pressure measurements recorded the impact of a simulated bone fragment on sections of explanted bovine spinal cord. The model simulated the PLL and the posterior elements. The status of the PLL had a significant effect on both the maximum occlusion of the spinal cord and the time for occlusion to occur. Raising the fragment velocity led to an overall increase in the spinal cord deformation. Interestingly the dura mater appeared to have little or no effect on the extent of occlusion. Conclusions. These findings may indicate the importance of the dura's interaction with the cerebrospinal fluid in protecting the cord during this type of impact.