摘要
目的 分析脊柱前中柱稳定性对椎弓根螺钉内固定器固定后前屈压缩刚度的影响,并探讨其临床意义。方法 收集7具新鲜猪T_(10)～L_4节段胸腰椎脊柱标本,“Ⅴ”形切除L_1椎体并压缩至闭合,造成前中柱不稳,模拟L_1骨折后安放AF椎弓根内固定器,进行前屈-压缩测试,分别计算完整标本、损伤标本和内固定后标本的前屈-压缩刚度。结果 完整标本、损伤标本和固定后标本的前屈-压缩刚度分别为413.9±118.6N/mm、136.6±31.6N/mm、240.5±51.4N/mm。相互间差异显著 (P<0.001)。结论 脊柱前中柱失稳后,经椎弓根螺钉内固定器械固定不能使其恢复到正常的机械力学性质,特别是前屈-压缩方向上。胸腰椎脊柱骨折经椎弓根螺钉系统固定后恢复前中柱的机械力学性质,减少其载荷分享是防止术后角度丢失,避免内固定器械固定失败的关键。
Objective To evaluate biomechanical roles of anterior and middle column on flexion-compression stiffness for pedicle screw device fixation in thoracolumbar spine. Methods A model of L1 body fracture was produced on seven specimens of fresh pig cadaver spine from T10 to L4. AF pedicle screw device was applied in the specimen to strength the injured level. Stiffness of flexion-compression was measured in intact, injured and stabilized specimens. Results Stiffness under flexion-compression in intact, injured and stabilized specimens were 413.9±118.6 N/mm,136.6 ± 31.6 N/mm, 240.5± 51.4 N/mm, respectively. There were significant difference in each group (P<0.001). Conclusion In thoracolumbar spine with deficiency of anterior and middle column, pedicle screw device fixation can not provide efficient stability, especially in flexion-compression. Recovering mechanical property and reducing load-sharing of anterior and middle spinal column are valuable measures for prevention of the implant failure.
出处
《骨与关节损伤杂志》
2003年第9期614-616,共3页
The Journal of Bone and Joint Injury
