P6. Hydrodynamic change of cerebrospinal fluid flow works for scoliosis formation in a kaolin-induced rabbit model

Abstract

BACKGROUND CONTEXT Syringomyelia (SM) is often found in scoliosis patients, but the relationship between them is still obscure. The hydrodynamic change of cerebrospinal fluid (CSF) flow has been believed as an important reason of SM. The changes of CSF flow should be included in the researches of scoliosis and associated-SM. PURPOSE Based on a kaolin-induced SM-associated scoliosis rabbit model, the potential relationship between cerebrospinal fluid flow (CSF) flow and scoliosis was explored through magnetic resonance image (MRI) analysis and radiography. STUDY DESIGN/SETTING An experimental study evaluated the relationship between CSF flow and scoliosis formation. PATIENT SAMPLE A total of 50 Japanese white rabbits were included in this study: 40 for experimental kaolin induction, 10 as the control: performing the same surgical process but using the 0.9% saline to instead of kaolin injection. OUTCOME MEASURES The Cobb angle of spinal curve on the coronal plane, the peak velocities of CSF flow, including up-flow (VUmax) and down-flow (VDmax) were measured at different phases. METHODS In 40 rabbits, before and after injecting kaolin into C7 spinal cord, through phase contrast–cine MRI (PC-cine MRI) and radiography, CSF flow and spinal curve formation were recorded at consecutive phases. According to the final formation of scoliosis, the rabbits were divided into 2 groups: scoliosis (group S) and non-scoliosis (group Non-S). The relationship between the changes of CSF flow velocity and scoliosis formation were analyzed. RESULTS In the 37 survived rabbits after kaolin-induction, spinal curve and/or syrinx were observed from week 6. At postoperative 12 weeks, scoliosis was observed in 73.0% animals and involved in group S and the mean final Cobb angle was 27.4°, and the other 10 without scoliosis were involved in group Non-S. In the control, either scoliosis or SM was observed in none. From the comparison between the 2 groups, the differences of the velocities of CSF flow were more obviously from week 4 to 12 after induction, especially at week 6. In the group S, the peak velocity of CSF flow was diseased gradually after induction. Moreover, the changes of VDmax and VUmax from preoperation to postoperative 12 weeks positively correlated to the final Cobb angle (P CONCLUSIONS The SM-associated scoliosis can be induced by kaolin injection into rabbit cervical spinal cord. In this model, the formation of scoliosis is correlated to the hydrodynamic status of CSF flow. The change of CSF flow could be an important potential factor working for the formation of scoliosis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.