椎间失稳对椎体形态与骨密度影响实验分析

目的：探讨腰椎椎间失稳对椎体形态和骨密度的影响。方法：27只兔随机分为手术和对照组，手术组沿L3～6棘突后正中切开，剥离两侧肌肉，切除棘上、棘是韧带，咬除关节外后1／2；对照组作相继同皮肤切口。于术后4、8月行X线和骨密度检查。结果：手术组L3～6椎体相继出现楔形样变、软骨下骨化和骨赞形成，腰椎呈后凸畸形，椎体前后壁高度比和骨密度值与对照组的差异具有显著性意义，椎体楔变和骨密度减少随退变进程加重。结论：腰椎椎间失稳可诱发椎体楔变和骨密度减低，致脊柱后凸畸形及骨质疏松。

EXPERIMENTAL STUDY OF MORPHOLOGICAL AND BONE MINERAL DENSITY CHANGES IN LUMBAR VERTEBRAL BODIES INDUCED BY INTERVERTEBRAL INSTABILITY

Objective:To observe the morpholgical and bone mineral density changes in lumbar vertebral bodies caused by instability of the spinal intervertebral equilibrium system.Methods:Twenty-seven rabbits were divided into an operating group and a control group.The operating group was incised through posterior approach along spinous process and resected the supraspinal and interspinal ligament and the posterior half of the zygapophysial joint between the third and the sixth lumbar spine .The control group was incised only by he skin .All of the rabbits were examined four and dual eight months later with roentgenogram and dual energy radiograph absorptiometry.Results:In the operating group,all lumbar spines were recurved .The height ratio of the anterior to the posterior border and the bone mineral density were lower than that of the control group with a significant difference.Conclusions:Wedging and bone mineral density decreasing of the vertebral body may be induced by spine instability,which contribute to kyphosis and osteoporosis of th spine.