The effect of bone fragment size and cerebrospinal fluid on spinal cord deformation during trauma: an ex vivo study Laboratory investigation

Object. The purpose of the Study was to assess the effect of CSF and the size of the impacting bone fragment area on spinal cord deformation during trauma. Methods. A transverse impact rig was used to produce repeated impacts on bovine and surrogate cord models. Tests were recorded with high-speed video and performed on specimens with and without CSF and/or dura mater and with 3 different impactor areas. Results. The CSF layer was found to reduce the maximum cord deformation significantly. A 50% reduction in impact area significantly increased the maximum cord deformation by 20-30%. The surrogate model showed similar trends to the bovine model but with lower absolute deformation values. Conclusions. Cerebrospinal fluid protects the cord during impact by reducing its deformation. A smaller bone fragment impact area increases the deformation of the cord, in agreement with clinical results, where a higher impact energy-possibly giving rise to smaller fragments-results in a worse neurological deficit. (DOI: 10.3171/2009.1.SPINE08286)