阻断双侧终板营养途径构建山羊椎间盘退变模型

The establishment of a goat model of intervertebral disc degeneration by blocking bilateral endplate nutritional pathways

目的通过建立山羊腰椎双侧终板营养途径阻断的动物模型,观察椎间盘退变(IDD)的情况,研究椎间盘营养途径与IDD的相关性。方法选取8只24月龄雌性关中山羊,每只山羊L2~3、L3~4作为实验椎间盘,麻醉后在平行于终板2 mm的椎体骨质处造成骨缺损,并使用骨水泥填塞,阻断椎体和终板之间的营养通路,L1~2、L4~5作为对照椎间盘。分别于术后4、12、24、48周行X线、MRI检查,各时间点随机处死2只山羊,采集椎间盘标本,计算骨水泥有效阻断面积、椎间高度指数(DHI)和Pfirrmann分级,并行HE、Masson三色、蛋白多糖、番红O染色组织学检查。结果术后骨水泥有效阻断面积达49.6%~69.6%(60.7%±5.3%)。术后48周时实验椎间盘DHI百分比为60.5%~81.7%(72.7%±5.6%),椎间高度丢失较对照差异有统计学意义(P<0.01);术后48周时实验椎间盘Pfirrmann分级为3~5(4.0±0.7)分,较对照差异有统计学意义(P<0.01)。组织学检查证实,实验椎间盘术后12周即发生退变,并随时间(24、48周)逐步加重。结论骨水泥填塞阻断双侧终板营养途径可以构建山羊IDD的动物模型,阻断终板营养途径可以导致IDD发生。

Objective To establish the goat model of intervertebral disc degeneration(IDD)by blocking bilateral endplate nutritional pathways with bone cement injection,and to study the correlation between intervertebral disc nutrition pathway and IDD.Methods Eight 24-month old female goats from guanzhong were selected as experiment samples.Two lumbar intervertebral discs(L2~3 and L3~4)were used as experimental discs,the bone defects were made in the adjacent vertebrae bone 2 mm away parallel to both endplates after anaesthesia,and then filled with the bone cement to block the nutritional pathways between the vertebrae and endplates,and the other two lumbar intervertebral discs(L1~2 and L4~5)remained intact as normal controls.And X-ray,magnetic resonance imaging(MRI)examination were performed at 4,12,24 and 48 weeks postoperation,respectively;two goats were randomly killed at each time point,and intervertebral disc specimens were collected.The effective blocking area of bone cement,intervertebral height index(DHI)and Pfirrmann grading were calculated,and histological examination was performed,including HE staining,Masson trichromatic staining,proteoglycan staining and pink O staining.Results The effective blocking area of bone cement reached 49.6%~69.6%(60.7%±5.3%).At 48 weeks postoperation,the percentage of DHI of experimental discs was 60.5%~81.7%(72.7%±5.6%),the intervertebral height loss had statistical difference,compared the control discs(P<0.01);Pfirrmann classification of experimental discs was 3~5(4.0±0.7)points,there was statistical difference,compared with the control discs(P<0.01).Histological examination confirmed that the degeneration of the experimental intervertebral disc occurred at 12 weeks after operation,and gradually aggravated with time(24,48 weeks).Conclusions The goat model of IDD can be established successfully by blocking bilateral endplate nutritional pathways with bone cement injection.The severe inhibition in the endplate nutritional pathways can lead to IDD.