纹牙弧轨钉板系统治疗腰椎单节段失稳性疾病的生物力学测试

Biomechanical test on the curative effect of thread-tooth arc-track screw-plate system in the treatment of lumbar monosegment instability diseases

目的:评价纹牙弧轨钉板系统治疗腰椎单节段失稳性疾病的生物力学性能。方法:取4具新鲜猪L2～S1节段脊柱标本,分别将4具标本标记为1号、2号、3号、4号,并制成L3～4椎间失稳模型。分别用自行研制的纹牙弧轨钉板系统模拟手术,行单节段经椎弓根固定,并进行轴向和弯曲扭转加载测试,观察纹牙弧轨钉板系统的应力、应变关系特点。结果:①在压缩实验中,最大载荷达到600 N时,压缩引起的正应力、剪应力均较小;载荷达600 N时,中心加载最大位移量为1.05 mm,偏心加载最大位移量为2.07 mm;在0～600 N轴向加载范围内,纹牙弧轨钉板系统应力与应变呈线性关系。②在弯曲扭转实验中,标本的应力与应变呈线性关系;当扭转角达到3°时,平均扭矩为18.06 N.m。结论:纹牙弧轨钉板系统具有较强的抗轴向和弯曲扭转载荷能力,能为腰椎失稳节段提供即刻的稳定性。

Objective：To evaluate the biomechanical property of thread-tooth arc-track screw-plate system in the treatment of lumbar monosegment instability diseases.Methods：Four fresh spine specimens of L2~S1 segments of pig were fetched and marked with No.1,No.2,No.3 and No.4 respectively,then L3~4 intervertebral instability models were built from them.They were administrated with simulating operation of transpedicular fixation in the single segment through self-designed thread-tooth arc-track screw-plate system,then they were processed with axial loading test and torsion test,and the stress-strain relation of the thread-tooth arc-track screw-plate system was observed.Results：①In the compressive test,the normal stress and shear stress caused by the compression were all low when the maximum load came to 600 N;when the load reached to 600 N,the maximum displacement of central loading was 1.05 mm and the maximum displacement of eccentric loading was 2.07 mm;when axial loading changed within the range of 0~600 N,there was a linear relationship between stress and strain for the thread-tooth arc-track screw-plate system.②In the bending torsion test,there was a linear relationship between stress and strain for the specimen;when torsion angle came to 3°,the average torque was 18.06 N·m.Conclusion：Thread-tooth arc-track screw-plate system can provide immediate stability for lumbar instability segments for its higher capacity to resist axial and torsion load.