MECHANICAL RESPONSES IN TRAUMATIC CERVICAL SPINE INJURIES SV HIGH-SPEED IMPACT

Abstract

INTRODUCTION-Spinal injuries resulted in personal suffering and significant loss to society. Although there are many studies about burst/crush fracture but the role of disc in traumatic processing is still not c1ear.[1] In this study we attempted to produce clinically relevant fractures in the porcine cervical spine under high speed trauma and put the emphasis on the difference of disc deformation between fractured and non-fractured specimens The load-time curve of fracture and intact specimens during trauma were also documented. MATERIALS AND METHODS-A total of ten fresh frozen lower cervical porcine spines were used. The specimens were three vertebrae segment(C3-C5). All the specimens were impacted through axial compression loading after QCT evaluation. To record the deformation of disc and body during impact, 1/16" steels ball were glued on the side of the specimens. The whole procedures were recorded by a high speed camera which went synchronically with the output load sequence. After impact, whether the specimens were fractured or not were examined and determined by Xray and CT scan. Then we compared the load-time curves, configure changes of disc and QCT values between the fractured and non-fractured groups. RESULTS AND DISCUSSIONS-There were six cases of fracture in total of ten specimens. The results were summarized in table 1. Figure 1 was the typical force-time curve including fractured and non-fractured groups. Height-time curve showed the changes of disc thickness in the anterior edge during impact (figure 2) Most of the fractured specimens were occurred in C4-C5 region and incompressible nature of disc was present even in high speed impact REFERENCE,Wilien J.et al A: The thoracolumbar crush fracture An experimental study on instant axial dynamic loading: the resulting fracture type and its stability Spine 9:624-631. 1984 Acknowledgments - Supported by NSC 832331-8-006-066 , Taiwan