背景:胸腰椎椎体切除后的脊柱重建方法有多种,但不同内植物的破坏载荷评价并未受到广泛重视.目的:测试牛胸腰椎椎体切除后不同内植物重建的破坏载荷.设计:随机对照实验.地点和对象:实验在上海大学完成,21具小于6周的小牛胸腰椎标本,由上海光明牛奶厂提供.干预:标本随机分为对照组、髂骨植骨组、人工椎体替代组、髂骨植骨+前路钢板组、人工椎体+前路钢板组、髂骨植骨+椎弓根钉组及人工椎体+椎弓根钉等7组.以50 N开始加载,直至标本破坏.主要观察指标:测量各标本在屈曲压缩状态下的最大破坏载荷.结果:正常小牛胸腰椎标本的极限载荷最高,平均为1 050 N,髂骨植骨组的最小,为80 N,仅有原始标本的45%,单纯钛合金人工椎体组平均破坏载荷比髂骨植骨组高16%,附加前路钢板及后路椎弓根钉固定,破坏载荷均高于单纯植入者.结论:不管是人工椎体还是髂骨替代其破坏载荷均小于原始标本,椎体重建的远期目标是融合而不是支撑.%BACKGROUND: Several methods have been described for spinal reconstruction after thoracic lumbar corpectomy. However, the load-to-collapse of different implants has not been widely emphasized and evaluated.OBJECTIVE: To investigate the load-to-collapse of different implants in thoracic lumbar spine.DESIGN: A randomized controlled experiment was conducted.SETTING and PARTICIPANTS: Twenty-one bovine thoracic and lumbar spine specimens under 6 weeks old were provided by Shanghai Bright Dairy. The experiment was finished in Shanghai University, Shanghai, China.INTERVENTIONS: The specimens were divided into seven groups which were control group(Intact spine, IS), iliac bone graft group(IBG), AHT-AVB gronp(AVB), IBG supplemented with anterior plate group(IBG + AP), AVB supplemented with anterior plate group (AVB + AP), IBG supplemented with posterior pedicle screw group(IBG + PS) and AVB supplemented with posterior pedicle screw group(AVB + PS) . Loading began from 50 N until the specimen was collapsed.MAIN OUTCOME MEASURES: The load-to-collapse under flextional compression were tested and determined for each specimen.RESULTS: The load-to-collapse in intact specimen is the highest with the mean score of 1 050 N while the iliac group is the lowest with the mean score of 80 N only which is 45% of the intact specimen. The average load-to-collapse in AVB fixation alone group is 16% higher than those in iliac bone graft group. After supplemented with anterior plate or posterior pedicel screw the load-to-failure value increased.
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