【作者】 武启军；

【导师】 王自立；

【作者基本信息】 宁夏医科大学 ， 外科学， 2010， 硕士

【摘要】 目的通过小牛脊柱模型的生物力学测试和临床研究,探讨单节段椎弓根内固定及单节段短椎弓根螺钉内固定的可行性。方法应用小牛脊柱制成力学测试模型,模拟体外L1-2边缘型脊柱结核前路病变椎体切除手术,即切除L1/2间盘和邻近终板,自体髂骨支撑植骨,后路采用椎弓根内固定系统进行不同方式的固定,并在试验机上模拟脊柱的轴向压缩、侧弯、屈伸和扭转运动,测试模型在轴向压缩、侧弯、屈伸和扭转方向上的运动范围(ROM, range of movement),计算相对运动范围(RROM, relative range of movement)并进行比较。本研究从4个方面分别探讨了单节段椎弓根内固定的稳定性:(1)比较长节段、短节段、单节段长椎弓根螺钉和单节段短椎弓螺钉内固定的生物力学稳定性:后路分别采用长节段、短节段、单节段长钉、单节段短钉进行固定,依次测量各运动方向上的ROM;(2)比较植骨和非植骨条件下的单节段固定的稳定性:分别测量植骨组和非植骨组在各运动方向上的ROM,同步测量后路固定棒的应力变化;(3)分析了橫连在单节段固定中的作用:分别测量无橫连组、一根横联组、二根横联组在各运动方向上的ROM;(4)对45例单节段固定的临床病例进行了随访观察和疗效分析。结果(1)在各个加载方向上长节段组、短节段组的RROM均小于单节段长钉组和单节段短钉组(P<0.05),而单节段长钉组和单节段短钉组的ROM均小于对照组(P<0.05),单节段短钉组和单节段长钉组的RROM相比较均无显著性差异(P>0.05);(2)在轴向压缩、侧弯、前屈和后伸方向上植骨组的RROM显著小于非植骨组(P<0.05),在扭转方向上两组比较无明显差异(P>0.05),在轴向压缩、侧弯、前屈和后伸方向上非植骨组后路内固定棒的应变较植骨组明显增加(P<0.05);(3)在扭转载荷下,一根橫连组和二根橫连组分别与无橫连组比较RROM显著减少(P<0.05),而在其余方向上的RROM比较无显著性差异(P>0.05),一根橫连组和二根橫连组相比在各个运动方向上均无显著性差异(P>0.05);(4)临床治疗随访结果显示单节段固定植骨融合优良,未见矫正度数的明显丢失;结论(1)单节段长钉固定的稳定性虽然低于短节段和长节段固定,但是高于对照组,达到了重建脊柱术后即刻稳定性的目的;单节段短钉内固定与单节段长钉内固定在轴向压缩、侧弯、屈伸、扭转方向上的即刻稳定性相近。(2)椎间植骨后增加了前中柱脊柱的载荷分享,减少了通过后路内固定器的应力,可明显增加脊柱在轴向压缩、侧弯、前屈后伸运动方向上的稳定性;然而在体外非融合状态下,椎间植骨对于脊柱扭转稳定性的影响不大。(3)在单节段椎弓根螺钉内固定中,橫连仅仅能够增强脊柱在扭转方向上的稳定性,使用一根橫连即能够达到最佳的对抗扭转的效果。(4)临床研究结果表明病椎间植骨融合、单节段内固定术可以有效的恢复和维持脊柱的稳定性。更多还原

【Abstract】 Objective Through biomechanical stability test of calf spine model and clinical research, explore feasibility of monosegment pedicle instrumentation (MSPI) and monosegment short pedicle instrumentation used in treatment for spinal tuberculosis;Method Calf spines were made into the mechanical test models of simulating resecting operation on spinal tuberculosis, being cut off the L1/2 intervertebral discs and the adjacent end plates, auto-iliac grafting and posterior being fixed with different method. Simulate spine motion in axial compression, lateral bending, flexion-extension and rotation and test range of movement(ROM) in all move directions. Calculate and compare relative range of movement(RROM). The research was mainly composed of four parts to discuss the stability of MSPI:(1) Compare the biomechanical properties of long segment pedicle instrumentation(LSPI), short segment pedicle instrumentation(SSPI), monosegment instrumentation with long pedicle screw (MILPS), monosegment instrumentation with short pedicle screw (MISPS): Posterior fix with LSPI,SSPI,MILPS,MISPS. Test ROM in all move directions;(2)Compare stability of MSPI with and without intervertebral bone graft: Separately test ROM of graft group and non-graft group in all directions and synchronously measure stress along the posterior internal fixation;(3)Analysis the effect of cross-linkage on monosegment pedicle instrumentation: Test ROM of the models without cross-linkage, with 1 and 2 cross-linkages in all directions;(4)Follow up 45 cases with monosegment pedicle instrumentation and analysis the curative effect.Result(1) Relative range of movement (RROM) of LSPI and SSPI were significantly smaller than that of MILPS and MISPS in all loading directions (P<0.05).However, range of movement(ROM) of MILPS and MISPS were smaller than that of control group(P<0.05); no statistical difference of the RROM was found between MISPS and MILPS(P>0.05);(2) The RROM of the models with bone graft was significantly lower than that of the ones without bone graft in axial compression, lateral bending and flexion-extension (P<0.05). However, no significant difference was found between them in rotation (P>0.05). In axial compression, lateral bending and flexion-extension the stress along the posterior internal fixation in group without bone graft was significantly increased than that in group with bone graft (P<0.05);(3) The RROM of fixation with 1 cross-linkage and 2 cross-linkages was significantly lower than that of fixation without cross-linkage in rotation (P<0.05), but there is no statistical difference in other directions (P>0.05). However, comparison of RROM between 1 and 2 cross-linkages was no significantly different in all directions (P>0.05);(4)The result of follow up showed that graft got well fused in monosegment fixation. There was no significant loss of correction angle;Conclusion(1)The stability of MILPS was significantly lower than that of LSPI and SSPI, but higher than that of control group. MILPS could reconstruct instant stability of spine; With iliac struting graft in anterior and mid column, MISPS can provide identical instant stability compare with MILPS in axial compression, lateral bending, flexion-extension and rotation;(2)Intervertebral bone graft could increase the load-sharing on the anterior and mid column , decrease stress along posterior internal fixation. It could increase the stability of spine in axial compression, lateral bending, flexion - extension, Otherwise, it effects little in rotation without interbody fusion;(3)With monosegment pedicle instrumentation, cross-linkage only increased torsional stability of spine. With 1 cross-linkage, the fixation will achieve the best effect to resist rotation;(4) The result of clinical research confirmed that bone-graft and fuse intervertebrae with monosegment pedicle instrumentation could reconstruct and sustain stability of spine effectively;更多还原