摘要
目的 探讨新型脊柱后路内固定器 (NSPF)的设计并进行生物力学分析 .方法 选取 8具新鲜尸体脊柱标本 ,截取 L1- S2脊柱节段 (INT) ,制作 L3椎体损伤模型 .分别安装 NSPF和 RF内固定器 .在 SANS材料实验机上 ,以频率0 .5 Hz加载变化 (44 0± 16 5 ) N对标本进行 10 0 0 0次疲劳实验 .记录初始状态、15 0 0次和 10 0 0 0次疲劳后各组在载荷 5 0 0N时固定节段 Y轴位移 ,代表刚度 .结果 经 15 0 0次和10 0 0 0次疲劳后 NSPF组及 RF组均保持良好刚度 ,两种内固定组间无明显差异 (P>0 .0 5 ) .结论 NSPF能有效地使骨折复位 ,具有节段短、创伤小、操作容易等特点 ;生物力学上达到良好的稳定性 .
AIM To evaluate the new spinal posterior fixation device (NSPF) on the models of unstable thoracolumbar burst fractures. METHODS In the fracture models, fatigue characteristics of two dorsally applied spinal fixation implants (RF and NSPF) were determined using lumbosacral cadaveric spine, with an L3 burst fracture, loaded cyclically in combined compression(maximum 605 N) and bending moment (maximum 16 Nm) for up to 10000 cycles. Displacement transducers monitored motion at the site of instability. Flexibility at these segments was then calculated. RESULTS Inthe fracture models, a one way analysis of variance showed that NSPF and RF allowed significantly more rigidity across the site of instability than intact spine ( P <0.05). There was no significant difference between NSPF and RF devices. Failure of RF screws occurred in one of 4 constructions. There was no metal failure in NSPF implants. CONCLUSION NSPF might be preferable because short motion segments are immobilized. There is more rigidity across the adjacent segments and batter corrected in kyphotic deformity and translation. It is easy to opterate on in clinical treatment. In vitro fatigue testing of spinal imlpants helps demonstrate potential design weaknesses so that improvements can be made before their clincal application in humans.
出处
《第四军医大学学报》
北大核心
2002年第17期1577-1579,共3页
Journal of the Fourth Military Medical University
关键词
胸腰椎骨折
生物力学
疲劳
脊柱内固定器
thoracolumbar burst fractures
biomechanics
fatigue
spinal instrumentation
