CAJ | 학술논문

目的:探讨和评价椎弓根螺钉不同置钉深度对胸腰椎骨折矢状面重建的生物力学作用.方法:6具新鲜人尸体固定腰段(L_1～L_3节段)脊柱标本,以预损伤方法制作胸腰椎骨折模型.选用直径为6 mm的USS椎弓根螺钉内固定系统,在L_1和L_3椎体各植入2枚Schanz钉,在L_1和L_3前缘正中各植入1枚空心钉,两空心钉根部之间距离设为正常的高度.在椎体前方轴向加载(前负荷),螺钉间的轴向加压模拟撑开复位操作(后负荷).分别在椎体后缘(D1)、椎弓根钉道1/2(D2)和钉道全长(D3)3个置钉深度轴向加载,观测两空心钉根部的直线距离,以后负荷加载至恢复原高度为止,记录椎弓根螺钉置钉深度、骨折椎体高度及后负荷.结果:在3种不同的置钉深度时,随着后负荷的增加,伤椎椎体高度均相应增大,但增加幅度有所不同.当骨折椎体达到完全复位时,D1、D2、D3工况下后负荷分别为 (2 630±13)g、(2 339±61)g和(2 221±164)g.D1与D2之间、D1与D3之间差异有统计学意义(P < 0.01),而D2与D3之间差异无统计学意义(P > 0.05).结论:椎弓根螺钉植入椎体的深度与伤椎复位能力及胸腰椎骨折矢状面重建相关,其植入深度在椎弓根通道1/2至椎弓根通道全长时力学效果最佳.
목적:탐토화평개추궁근라정불동치정심도대흉요추골절시상면중건적생물역학작용.방법:6구신선인시체고정요단(L_1～L_3절단)척주표본,이예손상방법제작흉요추골절모형.선용직경위6 mm적USS추궁근라정내고정계통,재L_1화L_3추체각식입2매Schanz정,재L_1화L_3전연정중각식입1매공심정,량공심정근부지간거리설위정상적고도.재추체전방축향가재(전부하),라정간적축향가압모의탱개복위조작(후부하).분별재추체후연(D1)、추궁근정도1/2(D2)화정도전장(D3)3개치정심도축향가재,관측량공심정근부적직선거리,이후부하가재지회복원고도위지,기록추궁근라정치정심도、골절추체고도급후부하.결과:재3충불동적치정심도시,수착후부하적증가,상추추체고도균상응증대,단증가폭도유소불동.당골절추체체도완전복위시,D1、D2、D3공황하후부하분별위 (2 630±13)g、(2 339±61)g화(2 221±164)g.D1여D2지간、D1여D3지간차이유통계학의의(P < 0.01),이D2여D3지간차이무통계학의의(P > 0.05).결론:추궁근라정식입추체적심도여상추복위능력급흉요추골절시상면중건상관,기식입심도재추궁근통도1/2지추궁근통도전장시역학효과최가.
Objective: To explore and evaluate the biomechanic relationships between different depth of pedicle screw penetration with the sagittal plane reconstruction in thoracolumbar fracture. Methods:Six fresh cadaveric specimens of lumbar spine from L_1 to L_3 were used to make the model of thoracolumbar fracture. The system of universal spine system( USS )pedicle screw was adopted with the 6 mm diameter of screw. Each of two Schanz screws was implanted into the pedicles of L_1 and L_3 A canulated screw was fixed into the former of vertebral body in L_1 and L_3, and the distance of the two canulated screws was taken as the normal height. The axial loads were given while the pedicle screws were implanted at the depth of D1, D2 and D3, and the distance of the two canulated screw was measured as well as the distance was reduced to the normal height by axial load. The index measured included of the depth of pedicle screw penetration, the height of fractured vertebral body and afterload. Results: Along with the increasing of afterload, the height of injured vertebral body was increased accordingly, but the extent was different at three depth of pedicle screw penetration (D1, D2, and D3). While the injured vertebral body was reduced totally (reduced distance 0.00 mm), there was (2 630±13) g of afterload needed in Dl depth, and (2 339±61) g and(2 221± 164) g of afterload in D2 and D3 depth respectively. There was significant difference in distance between D1, D2 and D3 (P< 0.01), however, no significant difference between D2 and D3 (P> 0.05). Conclusion: There is a relationship in the depth of pedicle screw penetration, the capacity of reduction and sagittal plane reconstruction. The depth of pedicle screw had a significant effect on the capacity of reduction for the injured vertebral body, which would be the best option in biomechanics when the pedicle screw was implanted more than 1/2 pedicle or all of it.