实验性腰椎失稳致椎间盘退变的放射影像学观察

目的：探讨腰椎失稳对椎间盘的影响及其X线表现。方法：选用新西兰兔27只，随机分为手术组15只，对照组12只，手术组沿L3-L6棘突作后正中切口，剥离骶棘肌，切除棘上，棘间韧带，咬除关节突关节外后1/2，对照组作相同皮肤切口即缝合，分别于术后4，8个月对腰椎行X线检查，结果：除外手术组切口感染1只，术后2和5个月各死亡1只，其余兔存活完好至取材，术后4个月，手术组均发生腰椎后凸畸形，出现软骨终板钙化的椎间盘超过半数，8个月时，所有椎间盘软骨终板均钙化，多数椎间隙狭窄。对椎间隙楔形样变。椎间隙狭窄。终板钙化和骨赘形成4种退变征象发生频数的统计分析显示，手术组与对照组间的差异具有显著性意义。结论：脊柱稳定对保持椎间盘生理功能意义重大，脊柱失稳可诱发椎间盘退变，后凸畸形和软骨终板钙化是失稳诱发的腰椎间盘退变早先发生和常见的X线征象。

Radiological Characterization of Experimental Rabbit Lumbar Intervertebral Disc Degeneration Caused by Spinal Instability

Objective:To observe the X ray signs in rabbit lumbar intervertebral disc degeneration induced by instability of the spinal equilibrium system.Methods:Twenty seven New Zealand white rabbits were divided into two groups,fifteen as the operating group,and another twelve as the control group.The operating group was incised through posterior approach along spinous process,then detached below erector spinal muscle,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 the skin.All of the rabbits were bred in standard circumstance,and examined four and eight months later with X ray.Results:In the operating group,incision infection occurred in one rabbit,and two rabbits died two and five months after the operation respectively.By the end of four months,all lumbar spines showed recurvation and the majority discs showed endplate calcification.By the end of eight months,all the cartilage endplates were calcified and the majority discs showed narrowing.Statistic analysis displayed that the radiological abnormality such as wedging,narrowing,endplate calcification,and osteophyte formation from the third to the sixth disc were more common than in the control group with a significant difference.Conclusions:The equilibrium of spine is of importance to its physiological function.Disc degeneration may be induced by spine nonequilibrium.Recurvation deformity and endplate calcification are early and common,X ray signs in disc degeneration caused by spinal instability.