Background： We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with sun＇ounding bone, and determine whether pedicle screws achieve good mechanical stability ...Background： We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with sun＇ounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. Methods： Twenty-four goats aged 2-3 years had Cosmic pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. Results： In the static control group, new bone was formed around the pedicle screw and on the screw surthce. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surlhce; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest （ROI） in the unilateral and bilateral dynamic fixation group were not significantly different （P 〉 0.05）, but were lower in the fixed groups than the static control group （P 〈 0.05）. This showed the description bone of the ROI in the static control group was greater than in the fixation groups. Under loading conditions, the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups （P 〉 0.05）： however the maximum pull force of the fixation groups was significantly less than the static control group （P 〈 0.01 ）. Conclusions： Fibrous connective tissue formed at the bone-screw interface tinder unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.展开更多
目的:采用有限元分析方法,评估传统椎弓根轨迹置钉(traditional trajectory,TT)技术与改良皮质骨轨迹置钉(modified cortical bone trajectory,MCBT)技术在不同骨质疏松条件下的腰椎生物力学性能差异。方法:采用CT扫描技术获取骨质疏松...目的:采用有限元分析方法,评估传统椎弓根轨迹置钉(traditional trajectory,TT)技术与改良皮质骨轨迹置钉(modified cortical bone trajectory,MCBT)技术在不同骨质疏松条件下的腰椎生物力学性能差异。方法:采用CT扫描技术获取骨质疏松患者的腰椎断层图像,然后对L4腰椎结构进行三维重建并进行验证。通过改变骨密度,在骨量减少(A1)、中度骨质疏松(A2)、重度骨质疏松(A3)中分别构建两种钉道设计。一种在TT技术中使用传统双螺纹椎弓根螺钉(TT组),直径6mm,全长45mm;另一种在MCBT技术中使用的变径全皮质骨螺纹螺钉(MCBT组),直径4~5.5mm,全长45mm。分析不同骨质疏松条件下,两种钉道设计对螺钉轴向抗拔出力、螺钉稳定性(上、下、左、右工况的载荷位移比,即螺钉尾端向其垂直轴的上、下、左、右位移0.1mm时载荷值与其位移的比值)以及腰椎活动度(前屈、后伸、侧弯及轴向旋转时)的影响。结果:在轴向抗拔出力方面,MCBT组在A1、A2、A3中较TT组分别提高93.5%、96.5%、98.5%。在稳定性方面,上、下、左、右工况在A1、A2、A3下,MCBT组螺钉的载荷位移比,相对于TT组分别提升42.2%、40.8%、41.7%;49%、49%、51.5%;82.4%、81.5%、85.2%;73.1%、70.8%、72.5%。在腰椎活动度方面,前屈时在A1、A2、A3下,TT组较MCBT组增加25%、26.6%、28.7%;后伸时在A1和A2下,TT组比MCBT组增加24.5%、22.9%,而在A3下,差异无显著性意义(P>0.05);而在侧弯和轴向旋转时,MCBT组在A1、A2、A3下相比TT组仅有轻微增加(P>0.05)。结论:在不同程度骨质疏松分级下,MCBT技术仅在椎体轴向旋转和侧屈时的稳定性上弱于TT技术,但在轴向抗拔出力、螺钉稳定性及椎体前屈、后伸时的稳定性上优于TT技术。展开更多
目的:探讨应用枕骨螺钉-棒-多轴螺钉内固定系统行枕颈固定融合术治疗“三明治”畸形伴寰枢关节脱位的临床效果。方法:回顾性分析2017年1月~2023年1月于我院因“三明治”畸形伴寰枢关节脱位行后路复位、植骨融合、枕颈内固定术的62例患者...目的:探讨应用枕骨螺钉-棒-多轴螺钉内固定系统行枕颈固定融合术治疗“三明治”畸形伴寰枢关节脱位的临床效果。方法:回顾性分析2017年1月~2023年1月于我院因“三明治”畸形伴寰枢关节脱位行后路复位、植骨融合、枕颈内固定术的62例患者,其中男性19例,女性43例,年龄51.1±23.5岁(29~72岁)。根据内固定系统枕骨端螺钉固定方式不同将患者分为两组:A组(38例)采用枕骨螺钉-棒-多轴螺钉内固定系统,男12例,女26例,年龄50.9±24.8岁(29~72岁),影像学表现脑干或颈髓受压30例、脊髓空洞6例、Chiari畸形2例;B组(24例)采用枕骨板-棒-多轴螺钉内固定系统,男7例,女17例,年龄51.4±22.4岁(32~69岁),影像学表现脑干或颈髓受压16例,脊髓空洞6例,Chiari畸形2例。A组随访时间36.5±11.8个月,B组随访时间36.1±9.8个月。两组患者年龄、性别、随访时间、影像表现无统计学差异(P>0.05)。收集并比较两组的术中出血量、手术时间、并发症发生率。术前及末次随访时进行颈部疼痛视觉模拟量表(visual analog scale,VAS)评分、颈椎功能障碍指数(neck disability index,NDI)、日本骨科协会(Japanese Orthopaedic Association,JOA)评分,术后1周及末次随访时测量两组患者CT植骨融合部横断面及矢状面骨性融合面积,术前、术后1周及末次随访时测量两组患者寰齿前间隙(atlantodental interval,ADI)、脊髓可用空间(space available for cord,SAC)、斜坡-椎管角(clivus canal angle,CCA)、延髓-脊髓角(cervico-medullary angle,CMA)。结果:A组术中出血量362.4±89.1mL、手术时间144.8±35.6min,B组术中出血量345.1±93.7mL、手术时间143.7±36.2min,两组间无统计学差异(P>0.05)。随访期间两组均无脊髓损伤、脑脊液漏等严重并发症发生,B组有2例患者出现连接棒断裂,3例患者出现复位丢失。两组术前NDI、VAS评分、JOA评分与末次随访比较有显著性差异(P<0.05),两组同时间点比较均无统计学差异(P>0.05)。两组术前ADI、SAC、CCA、CMA与术后1周及末次随访比较有显著性差异(P<0.05),两组同时间点比较均无统计学差异(P>0.05)。A组术后1周植骨融合部横断面面积、植骨融合部矢状面面积分别为385.44±84.51mm^(2)、290.28±110.41mm^(2),末次随访时分别为267.06±66.13mm^(2)、204.54±83.85mm^(2);B组术后1周分别为442.61±76.85mm^(2)、267.21±104.63mm^(2),末次随访时分别为172.43±37.37mm^(2)、124.87±48.10mm^(2),两组术后1周植骨融合部横断面面积和植骨融合部矢状面面积比较无统计学差异(P>0.05),末次随访时有显著性差异(P<0.05)。结论:应用枕骨螺钉-棒-多轴螺钉内固定系统枕颈固定融合术治疗“三明治”畸形伴寰枢关节脱位同枕骨板-多轴螺钉内固定系统相比疗效相当,但术后植骨融合效果更好,能达到可靠的枕颈固定。展开更多
文摘Background： We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with sun＇ounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. Methods： Twenty-four goats aged 2-3 years had Cosmic pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. Results： In the static control group, new bone was formed around the pedicle screw and on the screw surthce. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surlhce; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest （ROI） in the unilateral and bilateral dynamic fixation group were not significantly different （P 〉 0.05）, but were lower in the fixed groups than the static control group （P 〈 0.05）. This showed the description bone of the ROI in the static control group was greater than in the fixation groups. Under loading conditions, the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups （P 〉 0.05）： however the maximum pull force of the fixation groups was significantly less than the static control group （P 〈 0.01 ）. Conclusions： Fibrous connective tissue formed at the bone-screw interface tinder unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.
文摘目的:采用有限元分析方法,评估传统椎弓根轨迹置钉(traditional trajectory,TT)技术与改良皮质骨轨迹置钉(modified cortical bone trajectory,MCBT)技术在不同骨质疏松条件下的腰椎生物力学性能差异。方法:采用CT扫描技术获取骨质疏松患者的腰椎断层图像,然后对L4腰椎结构进行三维重建并进行验证。通过改变骨密度,在骨量减少(A1)、中度骨质疏松(A2)、重度骨质疏松(A3)中分别构建两种钉道设计。一种在TT技术中使用传统双螺纹椎弓根螺钉(TT组),直径6mm,全长45mm;另一种在MCBT技术中使用的变径全皮质骨螺纹螺钉(MCBT组),直径4~5.5mm,全长45mm。分析不同骨质疏松条件下,两种钉道设计对螺钉轴向抗拔出力、螺钉稳定性(上、下、左、右工况的载荷位移比,即螺钉尾端向其垂直轴的上、下、左、右位移0.1mm时载荷值与其位移的比值)以及腰椎活动度(前屈、后伸、侧弯及轴向旋转时)的影响。结果:在轴向抗拔出力方面,MCBT组在A1、A2、A3中较TT组分别提高93.5%、96.5%、98.5%。在稳定性方面,上、下、左、右工况在A1、A2、A3下,MCBT组螺钉的载荷位移比,相对于TT组分别提升42.2%、40.8%、41.7%;49%、49%、51.5%;82.4%、81.5%、85.2%;73.1%、70.8%、72.5%。在腰椎活动度方面,前屈时在A1、A2、A3下,TT组较MCBT组增加25%、26.6%、28.7%;后伸时在A1和A2下,TT组比MCBT组增加24.5%、22.9%,而在A3下,差异无显著性意义(P>0.05);而在侧弯和轴向旋转时,MCBT组在A1、A2、A3下相比TT组仅有轻微增加(P>0.05)。结论:在不同程度骨质疏松分级下,MCBT技术仅在椎体轴向旋转和侧屈时的稳定性上弱于TT技术,但在轴向抗拔出力、螺钉稳定性及椎体前屈、后伸时的稳定性上优于TT技术。
文摘目的:探讨应用枕骨螺钉-棒-多轴螺钉内固定系统行枕颈固定融合术治疗“三明治”畸形伴寰枢关节脱位的临床效果。方法:回顾性分析2017年1月~2023年1月于我院因“三明治”畸形伴寰枢关节脱位行后路复位、植骨融合、枕颈内固定术的62例患者,其中男性19例,女性43例,年龄51.1±23.5岁(29~72岁)。根据内固定系统枕骨端螺钉固定方式不同将患者分为两组:A组(38例)采用枕骨螺钉-棒-多轴螺钉内固定系统,男12例,女26例,年龄50.9±24.8岁(29~72岁),影像学表现脑干或颈髓受压30例、脊髓空洞6例、Chiari畸形2例;B组(24例)采用枕骨板-棒-多轴螺钉内固定系统,男7例,女17例,年龄51.4±22.4岁(32~69岁),影像学表现脑干或颈髓受压16例,脊髓空洞6例,Chiari畸形2例。A组随访时间36.5±11.8个月,B组随访时间36.1±9.8个月。两组患者年龄、性别、随访时间、影像表现无统计学差异(P>0.05)。收集并比较两组的术中出血量、手术时间、并发症发生率。术前及末次随访时进行颈部疼痛视觉模拟量表(visual analog scale,VAS)评分、颈椎功能障碍指数(neck disability index,NDI)、日本骨科协会(Japanese Orthopaedic Association,JOA)评分,术后1周及末次随访时测量两组患者CT植骨融合部横断面及矢状面骨性融合面积,术前、术后1周及末次随访时测量两组患者寰齿前间隙(atlantodental interval,ADI)、脊髓可用空间(space available for cord,SAC)、斜坡-椎管角(clivus canal angle,CCA)、延髓-脊髓角(cervico-medullary angle,CMA)。结果:A组术中出血量362.4±89.1mL、手术时间144.8±35.6min,B组术中出血量345.1±93.7mL、手术时间143.7±36.2min,两组间无统计学差异(P>0.05)。随访期间两组均无脊髓损伤、脑脊液漏等严重并发症发生,B组有2例患者出现连接棒断裂,3例患者出现复位丢失。两组术前NDI、VAS评分、JOA评分与末次随访比较有显著性差异(P<0.05),两组同时间点比较均无统计学差异(P>0.05)。两组术前ADI、SAC、CCA、CMA与术后1周及末次随访比较有显著性差异(P<0.05),两组同时间点比较均无统计学差异(P>0.05)。A组术后1周植骨融合部横断面面积、植骨融合部矢状面面积分别为385.44±84.51mm^(2)、290.28±110.41mm^(2),末次随访时分别为267.06±66.13mm^(2)、204.54±83.85mm^(2);B组术后1周分别为442.61±76.85mm^(2)、267.21±104.63mm^(2),末次随访时分别为172.43±37.37mm^(2)、124.87±48.10mm^(2),两组术后1周植骨融合部横断面面积和植骨融合部矢状面面积比较无统计学差异(P>0.05),末次随访时有显著性差异(P<0.05)。结论:应用枕骨螺钉-棒-多轴螺钉内固定系统枕颈固定融合术治疗“三明治”畸形伴寰枢关节脱位同枕骨板-多轴螺钉内固定系统相比疗效相当,但术后植骨融合效果更好,能达到可靠的枕颈固定。
