摘要
目的比较跨节段椎弓根钉固定与三椎体六枚椎弓根钉固定术固定胸腰椎骨折的生物力学效果。方法采用8具新鲜小牛椎体标本(T_(11)～L_3),MTS机压缩制作L_1椎体爆裂性骨折模型。实验分完整状态组、骨折组、跨节段椎弓根钉固定组、三椎体六枚椎弓根钉固定组。应用脊柱三维运动试验机对标本进行前屈,后伸,左、右侧弯及左、右旋转6个方位的运动范围(ROM)测试并计算刚度值,所得数据进行统计学处理,比较各组间差异。结果脊柱骨折状态6个方向ROM均显著增加(P＜0．05),椎间刚度值明显降低(P＜0．05)；固定状态的ROM均较完整状态、骨折状态显著减小(P＜0．01),而刚度值均较完整状态、骨折状态增大,差异有显著性意义(P＜0．05)；跨节段椎弓根钉固定组与三椎体六枚椎弓根钉固定组之间的ROM、刚度值差异均无显著性意义(P＞0．05)。结论跨节段椎弓根固定与三椎体六枚椎弓根钉固定术在重建脊柱骨折稳定性方面,效果无明显差异。
Objective To compare the biomechanical properties between the two-level fixation by implantation of pedicle-screws into the adjacent upper and lower vertebrae of the fractured vertebra and the three-level fixation by implantation of pedicle screws into the fractured vertebra and its adjacent upper and lower vertebrae in the treatment of thoracolumbar burst fractures. Methods Eight fresh frozen calf spines were used in this study. Each specimen was tested in four models： intact model as the control, L1 burst fracture model, two-level fixation model, and three-level fixation model. The L1 burst fracture model was created on a biaxial material testing machine （MTS858 Bionix test system, America）. During the experiment, the flexion, extension, bilateral bending and axial rotation loadings were applied to the specimens and the range of motion （ROM） was measured with a three-dimensional laser analysis apparatus and the stiffness was calculated subsequently. One-way statistical analysis was used. Results The ROMs under six different loadings in the fracture model became larger obviously （ P 〈 0. 05） and the stiffness decreased （ P 〈 0. 05） . The ROMs in both fixation models were smaller than those in the other models （ P 〈 0. 01 ） and the stiffness increased distinctly （ P 〈 0. 05）. There were no significant differences in ROMs and stiffness between the two-level fixation and three-level fixation models （ P 〉 0. 05） . Conclusion Two-level fixation provides similar biomechanical stability as three-level fixation does in the reconstruction of unstable thoracolumbar fractures.
出处
《中华创伤骨科杂志》
CAS
CSCD
2006年第9期857-860,共4页
Chinese Journal of Orthopaedic Trauma
基金
广州市科委攻关项目(2005Z3-E0401
2005Z2-E0111)
关键词
脊柱骨折
生物力学
内固定器
伤椎固定
Spinal fracture
Biomechanics
Internal fixator
Fixation of fractured vertebra
