摘要
目的 评价聚甲基丙烯酸甲酯 (polymethylmethacrylate,PMMA)骨水泥强化椎弓根螺钉内固定对骨质疏松不稳定性胸腰椎损伤的即刻稳定性和反复载荷后的稳定性。 方法 6具新鲜老年女性骨质疏松脊柱标本 (T1 0 ～L5) ,制备L1 椎体节段不稳定性损伤模型后 ,椎弓根螺钉系统固定 ,进行左 /右侧弯、左 /右旋转和前屈 /后伸 6个运动方向的稳定性测试 ,并在MTS 85 8型材料试验机上进行屈 /伸疲劳试验。比较完整脊柱标本 (a)、损伤模型钢板固定未强化疲劳前 (b)、钢板固定未强化疲劳后 (c)、钢板固定强化后疲劳前 (d)、钢板固定强化后疲劳后 (e) 5种状态下脊柱的稳定性变化。 结果 在b、d、e三种状态下 ,6个运动方向脊柱的稳定性差异不明显 (P >0 .0 5 ) ,但均强于a、c状态 (P <0 .0 1)。 2 0颗螺钉未强化疲劳后有 19颗出现松动 ,而强化螺钉疲劳后未见螺钉松动。 结论 PMMA强化骨质疏松椎弓根螺钉内固定能明显增强脊柱的稳定性和抗疲劳能力。
Objective To ascertain the instant and post-repeated-bearing stability of augmentation pedicle screw fixation with polymethylmethacrylate (PMMA) bone cement on the unstable thoracolumbar fractures of osteoporotic spine. Methods Six fresh osteoporotic spines (T 10 -L 5) from old females were harvested and spine L 1 was defected to make an anterior and posterior column unstable model. Each specimen was fixated with plate and the stability testing performed on directions of left and right flexions, left and right rotations, anterior extension and lateral bending. The fatigue experiment on extension and bending was done on MTS 858. The biomechanical stability of different conditions was observed and compared: (a) normal specimens, (b)defect model fixated with plate with no augmentation or fatigue, (c) plate fixation after fatigue without augmentation, (d) plate augmented with PMMA without fatigue and (e) plate fixation after augmentation and fatigue. Results At 6 directions, the stability of 6 specimens had no significant difference under conditions of b, d and e ( P >0.05) but was stronger than that under conditions of a and c ( P <0.01). Under condition c, 19 out of 20 screws loosened but no loosening occurred under condition e. Conclusions Augmentation osteoporotic pedicle screw fixation with PMMA can strengthen stability and anti-fatigue capacities of the osteoporotic spine.
出处
《中华创伤杂志》
CAS
CSCD
北大核心
2003年第6期358-361,共4页
Chinese Journal of Trauma
基金
广东省科委基金资助项目 ( 99M0 0 2 10G)
