兔腰椎间盘严重退变骨水泥成形术模型建立与鉴定

Establishment and identification of cementoplasty model of rabbit lumbar disc with severe degeneration

目的建立兔腰椎间盘严重退变骨水泥成形术模型并进行鉴定。方法选用新西兰白兔6只,手术干预前摄腰椎正侧位X线片并进行MRI扫描Pfirrmann分级,之后通过腹外斜肌与腰大肌间隙入路手术去除兔腰2~3椎间盘髓核组织及部分纤维环模拟腰椎间盘严重退变状态。饲养6周后相应腰椎节段椎间盘进行MR扫描Pfirrmann分级,确认相应腰椎节段椎间盘符合严重退变影像表现后再次手术显露相应椎间隙并注入骨水泥。1周后再次摄腰椎正侧位X线片并行MRI扫描Pfirrmann分级,终末处死并解剖动物检查椎间盘内骨水泥填充情况。结果兔腰椎间盘退化模型建立6周后磁共振Pfirrmann分级为Ⅴ级。椎间隙骨水泥注射后1周其术后磁共振Pfirrmann分级为Ⅳ。骨水泥注射模型1周后拍摄手术节段X线片显示骨水泥较好地填充于腰2~3间隙,椎间隙高度接近正常状态。终末处死并解剖动物发现腰椎节段椎间盘内骨水泥填充良好无脱落或松动。结论通过腹外斜肌与腰大肌间隙入路,手术去除椎间盘髓核组织及部分纤维环6周后,往椎间隙内注入骨水泥,可获得较为可靠的新西兰大白兔腰椎间盘严重退变骨水泥成形术的动物模型。

Objective To establish and identify the rabbit model of lumbar disc with severe degeneration.Methods Six New Zealand white rabbits were selected,lumbar X-ray and Pfirrmann grade by MR scan were performed before surgical intervention.Along the space of obliquus externus abdominis and psoas major,the front edge of L2 to L3 was exposed.Then,the nucleus pulposus and part of annulus fibrosus were removed to imitate severe degeneration of lumbar disc.After 6 weeks of rearing,the operated lumbar disc was graded by MR scan,confirming that the lumbar disc met the image of severe degeneration,and then exposed the intervertebral space and injected bone cement.One week later,the anterior lumbar X-ray and the MRI scan for Pfirrmann grading were taken.The animals were sacrificed and dissected to check the bone cement filling in the intervertebral disc.Results The rabbit MR Pfirrmann grade of intervertebral disk was V after 6 weeks of first operation.One week after intervertebral cement injection,the MR Pfirrmann grade wasⅣ.The surgical segment X-ray was taken one week after the cement injection,which showed that the cement was well filled in the L2-L3 gap and the vertebral space height was close to normal.Animals were sacrificed and dissected,the lumbar intervertebral disc was well filled with cement without shedding or loosening.Conclusions A reliable animal model of lumbar disc with severe degeneration in New Zealand white rabbits can be obtained by injecting cement into the intervertebral space after 6 weeks of removal of the intervertebral disc nucleus pulposus and part of the annulus fibrosus through the obliquus externus abdomins and psoas major intervertebral space.