【作者】 赵斌；

【导师】 马迅；

【作者基本信息】 山西医科大学 ， 外科学， 2010， 博士

【摘要】 背景胸腰椎骨折是脊柱外科的常见损伤,占脊柱损伤的10%-20%,近年来随着我国国民经济的发展及社会老龄化,工矿企业伤、交通伤及老年伤病造成脊柱骨折的发生率逐年增加,传统治疗胸腰椎骨折的方法是采用后路短节段椎弓根内固定术(short-segment posterior instrumentation, SSPI),它通过撑开复位使椎体高度恢复,纠正脊柱畸形,伸展后纵韧带使突入椎管内骨块达到一定程度的复位和减压。但其术后高度、角度的丢失及较高的内固定失败率是其在治疗胸腰椎骨折中所面临的巨大挑战,日益受到学者的重视。生物力学试验和影像学研究表明,不同向量的力均可造成椎体压缩骨折,椎体发生骨折时不仅外部皮质破损,椎体内的松质骨亦被压缩,椎弓根螺钉利用对前、后纵韧带和椎间盘纤维环的牵拉复位作用,虽能基本恢复伤椎的高度及外形,但对椎体内部松质骨的复位作用却十分微弱,骨折椎体经椎弓根钉复位后椎体内均出现明显的空隙,平均为5.25cm3,占椎体总体积的13.9%,对椎弓根钉复位后的椎体行CT扫描发现所有爆裂骨折椎体的内部特别是椎弓根层面的椎体前部依然存在骨缺损区域,其体积约为椎体大小的1／4,即形成所谓的“蛋壳样”空心椎,腔隙的存在意味著脊柱负重后出现椎体高度丢失的可能行,椎间盘纤维环不能得到有效支撑,造成椎体终板塌陷,后凸畸形以及内固定失败等并发症。椎间隙高度的丢失使脊柱前中柱丧失结构上的完整性,如不进行有效重建,内固定物长期承受过度载荷,晚期易发生内固定失败、骨折椎体塌陷及矫正度的丢失。伤椎重建术是经椎弓根通道完成伤椎终板复位,并向伤椎椎体空腔内置入不同填充材料以重建伤椎的生物力学特性,维持伤椎复位形态,减轻内固定物的应力负荷,从而减少术后并发症的发生。目前SSPI结合伤椎重建术主要用于治疗胸腰椎爆裂骨折；而经皮椎体成形术(Percutaneons vertebroplasty, PVP)和经皮椎体后凸成形术(Percutaneons kyphoplasty,PKP)主要用于治疗老年骨质疏松性压缩骨折,这两项技术都是经椎弓根通道完成椎体内重建,恢复伤椎的力学性能和减轻疼痛,但各有其适应症选择。本研究通过对经椎弓根通道椎体重建范围的解剖学研究,伤椎重建术治疗胸腰椎创伤性压缩骨折的生物力学研究,不同填充材料修复羊椎体内骨缺损动物载体实验及组织学研究,应用伤椎重建术治疗胸腰椎骨折的临床研究及椎体后凸成形装置的研制等方面,为经椎弓根伤椎重建术治疗胸腰椎骨折提供实验依据和临床指导。一、经椎弓根椎体重建术的解剖学研究目的：探讨胸腰椎经椎弓根通道行椎体重建术的相关径线及重建范围。方法：取5具新鲜人体胸腰椎标本,节段为T10-L2椎体,行X线及CT扫描(层厚为0.625mm,无间隔),将所得数据导入到Mimics软件中,测量每个椎体的椎弓根轴线长度(L)、椎弓根长度(L0)、宽度(W)及高度(H0)、椎体高度(H)、椎弓根入点在横断面可变化角度(α)及椎弓根入点在矢状面可变化角度(β),进一步计算出经单侧椎弓根通道行椎体重建术植骨的体积以及经椎弓根椎体重建占相应椎体体积的百分数。结果：T10-L2椎体椎弓根轴线长度平均分别为32.64±5.66mm、31.80±6.41mm、38.46±3.52mm、40.31±4.39mm及42.72±3.36mm。T10-L2椎体椎弓根长度平均分别为12.38±2.06mm、11.77±2.15mm、14.63±2.34mm、15.46±3.04mm及14.37±1.64mm；椎弓根宽度平均分别为5.09±0.26mm、5.79±1.10mm、7.35±1.87mm、7.17±0.69mm及7.14±0.84mm；椎弓根高度平均分别为9.76±1.43mm、10.83±0.77mm、11.16±0.78mm、11.33±1.26mm及11.16±0.96mm。椎体的平均高度平均分别为18.12±0.88mm、19.48±1.02mm、21.25±1.27mm、22.88±0.68mm及23.20±0.93mm。椎弓根入点在横断面可变化角度(α)平均分别为25.06±3.84°、30.87±7.28°、25.12±5.18°、20.55±1.54°及21.74±2.58°；椎弓根入点在矢状面可变化角度(β)平均分别为43.60±4.52°、49.48±10.30°、41.97±5.19°、40.29±6.49°及42.85±6.47°。T10-L2椎体经单侧椎弓根行椎体重建术植骨的体积平均分别为1.02±0.36cm3、1.30±0.43cm3、1.96±0.67cm3、1.84±0.48cm3及1.94±0.41cm3,占相应椎体体积的百分数分别为53.95%、55.68%、52.67%、49.5%及48.14%。结论：经椎弓根通道可有效行终板下复位及椎体内空腔填充,完成椎体重建术。二、伤椎重建治疗胸腰椎创伤性压缩骨折的生物力学研究目的：探讨胸腰椎骨折中采用不同填充材料行伤椎椎体重建术的生物力学特性及形态学变化。方法：取6具新鲜人体胸腰椎标本(T12-L2),应用INSTRON8874生物力学测试机制备成L1椎体创伤性压缩骨折模型,随机分为丙烯酸树脂骨水泥组及同种异体骨组,进行伤椎重建术。测试完整、损伤及椎体重建即刻三种状态下L1椎体的刚度、弹性模量、极限压缩强度,通过数据得出加载过程中椎体的应力应变关系。同时行不同状态下的X线及CT扫描,以观察椎体压缩骨折、复位及重建后影像学变化。测试结束后,两组分别随机选取一具标本,将L1椎体中部横断,观察L1椎体内大体形态学变化。结果：两种填充材料结合伤椎重建术可使L1椎体高度恢复至完整状态的98.95%。丙烯酸树脂骨水泥和同种异体骨行伤椎重建后即刻状态的整体刚度和弹性模量与完整及损伤状态相比差异有统计学意义(P<0.05)；两组间伤椎重建后即刻状态的整体刚度和弹性模量相比差异无统计学意义(P>0.05)。丙烯酸树脂骨水泥和同种异体骨组伤椎重建后极限抗压强度与完整状态相比差异有统计学意义(P<0.05)；两组间伤椎重建后极限抗压强度相比差异有统计学意义(P<0.05)。影像学显示伤椎重建术能有效的恢复椎体高度,达到解剖复位。重建后标本CT扫描及椎体横断剖面显示,未见骨水泥断裂,同种异体骨组可见骨块紧密嵌差。结论：丙烯酸树脂骨水泥或同种异体骨结合伤椎重建术可有效维持创伤性压缩骨折的复位及生物力学强度。三、不同填充材料在修复羊椎体内骨缺损的组织学研究目的：观察不同填充材料在修复羊椎体内骨缺损中的吸收与成骨特性。方法：采用成年健康山羊6只,全麻后俯卧位,从后方显露羊胸腰椎T12-L6节段,经双侧椎弓根开孔,深入刮匙,尽可能刮除椎体内松质骨形成骨缺损。每只羊的L1-6椎体分为四组,分别填充羊同种异体骨组、丙烯酸树脂骨水泥组及Cem-OsteticTM人工骨浆组,T12椎体空腔未填充作为空白对照。于术后4周、8周及12周分别处死2只动物,取出T12-L6椎体行CT扫描,观察椎体内骨缺损修复情况,将组织块制备为脱钙组织切片,行HE染色并进行组织学观察。结果：所有动物羊均成活,通过组织学观察发现,在12周时,空白对照组缺损处为纤维结缔组织结构,内无骨小梁结构,缺损区与正常骨小梁交界处可见散在的成骨细胞、破骨细胞及骨小梁；羊同种异体骨组缺损内吸收明显,有大量骨小梁,排列有一定方向,内有大量成骨细胞；丙烯酸树脂骨水泥组骨水泥-骨小梁界面可见大量缺损存在,散在均质淡红染的结构,内无细胞,周围可见大量炎细胞；Cem-OsteticTM人工骨浆组可见散乱的骨小梁,周围有大量成骨细胞和破骨细胞,部分骨小梁重构成形。结论：除丙烯酸树脂骨水泥组外,其余两种材料填充椎体内骨缺损处均可见生物降解性及成骨性存在,均可做为骨缺损填充材料,其中同种异体骨在成骨方面较为显著。空白对照组缺损处为纤维结缔组织填充,无骨小梁结构。四、应用伤椎重建术治疗胸腰椎骨折的临床研究第一节椎弓根内固定并伤椎重建术治疗胸腰椎爆裂骨折目的：评价经后路矫形固定结合椎体撬拨植骨术治疗胸腰椎骨折的临床疗效。方法：采用经后路椎弓根螺钉矫形固定,同时经椎弓根对骨折椎体进行撬拨,恢复椎体前中柱高度,并行椎体内植骨治疗30例(共34椎)胸腰椎骨折。男23例,女7例；年龄24-77岁,平均40.8岁。所有患者均为外伤性骨折,其中6例合并骨质疏松。植骨材料分别采用Cem-OsteticTM人工骨浆(3例)、自体骨(17例)和同种异体骨(10例)。随访观察患者疼痛视觉模拟评分(visual analogue scale, VAS)及影像学改变情况。结果：所有患者术后均获得12～24个月随访,平均18个月。术前、术后1周及末次随访,椎体前高平均分别为15.5±3.8mm、23.3±5.7mm和22.5±5.1mm；椎体后高平均分别为25.8±3.4mm、28.6±2.0mm和28.3±2.2mm；后凸角度平均分别为23.5°±7.6°、14.3°±7.1°和15.7°±7.5°；VAS评分平均分别为7.57±1.45、2.57±0.65和2.07±0.62。各项指标均较术前有显著改善,差异有统计学意义(P<0.05),而末次随访与术后1周比较差异无统计学意义(P>0.05)。随访期间内固定无松动、断裂等,骨折椎体密度等同或高于上、下相邻椎体,部分行后外侧植骨融合病例亦达到临床融合标准。结论：经后路矫形固定结合椎体撬拨植骨术治疗胸腰椎骨折,可有效恢复和维持椎体高度,提高骨折椎体密度,增强脊柱前中柱的稳定性。第二节经肌间隙入路与传统手术入路椎弓根内固定治疗胸腰椎骨折的比较研究目的：探讨经后路椎旁肌间隙入路治疗胸椎、腰椎椎骨折(T2-L5)的手术方法及与传统手术方法的比较研究。方法：2006年10月至2008年10月,连续52例无神经损伤表现的胸腰椎骨折患者纳入研究。男37例,女15例；平均年龄46.5岁(18-59岁)。T4骨折1例,T7骨折2例,T8骨折1例,T10骨折3例,T11骨折5例,T12骨折14例,L1骨折16例,L2骨折9例,L3骨折1例。依据Denis骨折分型,压缩型骨折17例,其余35例均为爆裂性骨折,椎管占位<1／3,突入椎管骨块均匀完整,无碎裂及翻转。患者随机分为两组,其中20例患者采用传统后正中入路,其余32例患者采用经后路改良椎旁肌间隙入路,均行后路椎弓根螺钉固定。结果：通过对比研究发现,后路椎旁肌间隙入路较传统后正中入路在于术时间上无明显差异,但在术中出血量、引流管放置时间、术后引流量、下地活动时间及疼痛视觉模拟评分(visual analogue scale. VAS)等方面具有显著优势,差异有统计学意义(P<0.05)。至2008年10月,所有患者均获得随访,平均时间15.6(9-24个月),所有患者伤椎椎体高度无丢失,内固定无松动、断裂。结论：经后路椎旁肌间隙入路治疗胸椎、腰椎骨折,完整保留脊柱后方复合体结构,具有创伤小,出血少,能早期下地活动,是一种有效地微侵入治疗方法,临床疗效满意。第三节可调式后凸成形装置的研制与应力负荷测试目的：研制一种新型金属可调式后凸成形装置,探讨其应用于伤椎重建的可行性。方法：利用钛合金的刚性及柔韧性,采用钛合金片组成灯笼状金属球,应用可调式旋进装置使金属球膨胀及回缩,并应用该器械进行椎体重建术,在人体新鲜胸腰椎标本(T12-L2)中进行可行性测试。采用白行设计的测试装置于INSTRON5544上测试单片金属片的最大应力载荷。结果：由钛合金钢片组成的灯笼球状金属球初始直径为6.0mm,可以通过胸腰椎椎弓根进入椎体内部,通过尾端可调式旋进装置调节使金属球膨胀,最大直径可达12mm,同时产生强大的撑开力,经生物力学测试,其单片金属片最大载荷为56.96±3.21N,应力为9.48±0.53Mpa。结论：可调式后凸成形装置可以经皮或结合后路椎弓根钉固定作为治疗包括骨质疏松椎体压缩骨折在内的各类型骨折,完成伤椎重建术,但其临床应用尚需进一步研究。总结1.利用CT扫描及计算机辅助技术对人体新鲜胸腰椎标本(T10-L2)相关径线和角度变化范围进行测量,通过矢状面角度测量我们发现经椎弓根通道完全可以达到上终板的复位,同时测算出经椎弓根通道椎体重建的体积,为经椎弓根通道完成终板下复位及椎体重建术提供理论依据。2.通过模拟创伤性椎体压缩骨折,测试其完整、损伤状态的生物力学特性,然后经椎弓根通道椎体内填充同种异体骨或骨水泥,测试伤椎重建后即刻状态椎体的刚度、弹性模量、极限压缩强度以及加载过程中椎体的应力应变关系,并进行影像学和大体观察,证实了两种不同填充材料可有效维持伤椎复位,具有与完整椎体相同的生物力学性能。3.通过对不同植骨材料填充羊椎体骨缺损的组织学观察研究证实,空白对照组缺损处为纤维结缔组织结构,内无骨小梁结构,缺损区与正常骨小梁交界处可见散在的成骨细胞、破骨细胞及骨小梁；羊同种异体骨组缺损内吸收明显,有大量骨小梁,排列有一定方向,内有大量成骨细胞；丙烯酸树脂骨水泥组骨水泥-骨小梁界面可见大量缺损存在,散在均质淡红染的结构,内无细胞,周围可见大量炎细胞；Cem-OsteticTM人工骨浆组可见散乱的骨小梁,周围有大量成骨细胞和破骨细胞,部分骨小梁重构成形。4.经后路椎弓根固定结合椎体撬拨成形,可有效地进行终板下复位,恢复椎体高度和角度,结合椎体内填充不同植骨材料维持复位和生物力学特性,具有简便、经济的特点,是在传统手术治疗基础上的进一步改进和完善,为手术治疗胸、腰椎骨折提供了一种新的术式选择。5.经后方椎旁肌间隙入路与传统手术入路比较保留了后方复合体结构完整,大大减少手术创伤,缩短手术时间。术中直视下操作,不用大量X线透视,与经皮微创手术同一间隙操作且较经皮椎弓根钉系统费用、用时及操作学习曲线方面均小,具有很大的实用性。本术式经解剖研究和临床操作可为T1-L5间骨折提供了一种微侵入的治疗方法。6.通过对自行研制的可调式后凸成形装置体外研究及生物力学测定证实了本装置在治疗椎体骨折伤椎重建中安全可行,操作简单,可重复使用,节约手术成本。可应用于经皮或结合后路椎弓根钉固定治疗骨质疏松性椎体压缩骨折在内的各型骨折的椎体重建。更多还原

【Abstract】 Background As the China’s national economic development and social aging population growth, industrial and mining injuries, traffic injuries geriatric spinal fractures caused by injury were increased year by year. Thoracolumbar spinal fractures are common injuries, accounting for 10% to 20% of the spinal injuries in recent years. Traditional treatment of thoracolumbar fractures is to use the short-segment pedicle instrumentation(SSPI), which restore vertebral height, correct spinal deformity and stretch the posterior longitudinal ligament to make the spinal canal bone to reaches a certain level of reduction and decompression. But the loss of angle and height of postoperative and the higher failure rate of the fixation in the treatment of thoracolumbar fracture were facing enormous challenges, which caused the increasing attention by the experts. Biomechanics experiments and imaging studies have shown that the different force vectors can be caused by vertebral compression fractures, when the vertebral fractures occur, the damage is not only in the external cortex, trabecular bone within the vertebral body was also compressed. Pedicle screw was used to the anterior and posterior longitudinal ligament and intervertebral disc annulus fibrosus for reduction, although this can basically restore the vertebral height and shape, but the internal vertebral trabecular bone reduction effect was very weak[2]. Vertebral fractures after pedicle screw reduction, which remained noticeable gap in both was average 5.25cm3, accounting for 13.9% of the total volume of vertebral body，and the CT scan after pedicle screw reduction found that all the internal of the bursting vertebral fractures, especially vertebral pedicle level, remained bone defect area in the front of the vertebral body, its volume is about a quarter size of vertebral body, which was namely the formation of "eggshell-like" hollow vertebrae, the presence of lacunar means that the vertebral height may be missing after load, vertebral endplate will collapse,and the intervertebral disc annulus fibrosus without effective support. The lost intervertebral height of the spine will break the integrity of the front and middle column of the spine. Without an effective reconstruction, internal fixation over a long time to bear load, prone to the failure of internal fixation, vertebral collapse and loss of correction in later period. Vertebral reconstruction is through the vertebral pedicle channel to complete endplate reset, and fill into the different filling materials into the injured vertebra vertebral body cavity to restore the biomechanical properties of vertebral, maintain the form of vertebral body, reduce the internal fixation the stress load, thereby reducing the incidence of postoperative complications. At present, the SSPI combined with vertebral reconstruction is major in treatment of thoracolumbar burst fractures; The percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) were major in used to treatment of osteoporotic compression fractures. The two technologies are used the pedicle channel to complete the vertebral reconstruction, rehabilitation of the mechanical properties of injured vertebral and reduce pain, but each has its indications.This study was discussed the reconstruction of the vertebral body through the pedicle channel, which were range of the anatomical studies of the pedicles channels, biomechanics research of the treatment of thoracolumbar vertebral reconstruction caused by traumatic compression fractures, the animal experimental and histological study of the different filling materials repair sheep vertebral bone defect and clinical research of the vertebral reconstruction in treatment of thoracolumbar vertebral fractures and self-designed kyphoplasty Device. This study is aimed to provide experimental evidence and clinical supervisors for vertebral reconstruction through the pedicle channels to treatment of thoracolumbar vertebral fractures.Part 1 Vertebral reconstruction through the pedicle channels:A anatomical studyObjective:To evaluate the line and the area of thoracolumbar (T10-L2) vertebral pedicle channel for vertebral reconstruction.Methods:Five fresh specimens of human thoracolumbar vertebrae (T10-L2), take the lateral of X-ray and CT scan, slice thickness of 0.625mm without interval, the CT date were inputed into Mimics 10.0 and then using the measurement tool in the Mimics to measure each vertebral body pedicle axis length(L), pedicle length(L0), width(W) and height(Ho), vertebral height(H), pedicle entry point in the sagittal plane angle (a) and the pedicle entry point in the cross-section angle (β), and further calculated the volume through vertebral pedicle channel for vertebral reconstruction.Results:The average thoracolumbar (T10-L2) vertebral pedicle axis length were 32.64±5.66mm、31.80±6.41mm、38.46±3.52mm、40.31±4.39mm and 42.72±3.36mm. The average vertebral pedicle length were 12.38±2.06mm、11.77±2.15mm、14.63±2.34mm、15.46±3.04mm and 14.37±1.64mm; The average pedicle width were 5.09±0.26mm、5.79±1.10mm、7.35±1.87mm、7.17±0.69mm and 7.14±0.84mm; The average pedicle height were 9.76±1.43mm、10.83±0.77mm、11.16±0.78mm、11.33±1.26mm and 11.16±0.96mm. The average vertebral height were 18.12±0.88mm、19.48±1.02mm、21.25±1.27mm、22.88±0.68mm and 23.20±0.93mm. The averageαangle were 25.06±3.84°、30.87±7.284°、25.12±5.18°、20.55±1.54°and 21.74±2.58°; The averageβangle were 43.6±4.52°、49.48±10.30°、41.97±5.19°、40.29±6.49°and 42.85±6.47°. The average volume of one side of vertebral body after vertebral reconstruction respectively were 1.02±0.36cm3、1.30±0.43cm3、1.96±0.67cm3、1.84±0.48cm3 and 1.94±0.41cm3, the corresponding percentage of total vertebral volume were 53.95%,55.68%, 52.67%,49.5% and 48.14%.Conclusion:It’s possible to use the pedicle channels for vertebral body reconstruction, reduction the end-plates and filling bone graft inside vertebral body.Part 2 Vertebral reconstruction in the treatment of thoracolumbar fractures:A biomechanical StudyObjective:To discuss the changes of biomechanical and morphological with different filling materials in combination with vertebral reconstruction in the treatment of thoracolumbar fractures.Methods:Six fresh specimens of human thoracolumbar vertebrae (T12-L2), using the INSTRONI8874 as prepared by biomechanical testing mechanism of traumatic compression fracture of L1 vertebral body were randomly divided into two group:the acrylic bone cement group and allograft bone group, and then reconstruction of vertebral. To test the stiffness, elastic modulus and ultimate compression strength at the state of integrity, injury and immediately vertebral reconstruction. At the same time take the X-ray film in order to observe the imageology changes of vertebral compression fractures, reduction and reconstruction. By the end of the test, two groups were randomly selected specimens of the L1 vertebral body with a cross-sectional, observing morphological changes of L1 vertebral body.Results:98.95% of the height of L1 vertebral body was restored by the two kinds of filling materials in combination with vertebral reconstruction(P>0.05). The stiffness and elastic modulus of the acrylic bone cement group and allograft bone group were significantly between the immediately state after the vertebral reconstruction and the state of integrity and the damage (P<0.05); The stiffness and elastic modulus of the immediately state after the vertebral reconstruction were not statistically significant between the two groups (P>0.05). The ultimate compressive strength of the acrylic bone cement group and allograft bone group were statistically significant between the immediately state after the vertebral reconstruction and the integrity state(P<0.05); The ultimate compressive strength was statistical significance between the two groups(P<0.05). The imaging of the vertebral reconstruction shows that the vertebral body height can be effective restoration to achieve anatomic reduction. The CT scan after reconstruction and vertebral cross-sectional sample profile showed no bone cement fracture, and bone allograft can be seen in close embedded.Conclusion:Acrylic bone cement or allograft bone injuries of vertebral reconstruction can effectively maintain the reduction of traumatic compression fractures and biomechanical strength. Part 3 Different filling materials in the repair of bone defects in sheep vertebral:A histological studyObjective:To observe characteristics of the bone absorption and formation with different filling material in the repair of bone defects in sheep vertebral body.Methods:Six adult healthy goats, revealed the rear structure after general anesthesia, using the curette to scrape off as much as possible the vertebral trabecular bone to form the bone defects through the bilateral pedicle channels. Each of the L1-6 vertebral were divided into four groups:sheep allogeneic bone group, acrylic bone cement group and Cem-OsteticTM artificial bone group. T12 vertebral body is not filled as a blank control. To execute two animals after four, eight and twelve weeks, remove the vertebral body tissue to prepare for decalcified tissue section, and then taking the HE staining for histological observation.Results:All animals are survived, at 12 weeks, the histological observation found that in the blank control group the fibrous connective tissue structure can be seen, and none of trabecular bone structure. The trabecular bone, osteoblasts and osteoclasts can be seen at the junction of normal trabeculae and defect area; The defects in the sheep allogeneic bone group absorbed significantly, there are a large number of osteoblasts and trabeculae bone, which arranged in a certain direction; In acrylic bone cement group, the cement-trabecular bone interface shows a large number of defects and scattered pink dye homogeneous structure without any cellexistence, surrounded by a large number of inflammatory cells; The defects in the Cem-OsteticTM artificial bone group can be seen scattered trabeculae, surrounded by a large number of osteoblasts and osteoclasts, including a part of remodeling trabecular bone.Conclusion:In addition to acrylic bone cement group, the other two kinds of material within the bone defect filled with vertebral body could be seen biodegradable and osteogenic presence, can be used as bone defect filling materials, and the allograft bone is more significant. There was no trabecula bone in the defect of the blank control group, which was filling with fibrous connective tissue.Part 4 Vertebral reconstruction in the treatment of thoracolumbar fractures:A clinical StudyChapter 1 Pedicle fixation and vertebral reconstruction for treatment of thoracolumbar fracturesObjective:To evaluate the posterior instrumentation combined with the vertebral lifted bone grafting to treat thoracolumbar fractures.Methods:Thirty patients (34 vertebrae) with thoracolumbar fractures were treated with posterior instrumentation fixation, which restored the anterior and middle column height of vertebral body and inserted the bone graft through the pedicle. There were 23 males and 7 females with an average age of 40.8 years (range,24-77 years). All patients were traumatic fractures (6 patients with osteoporosis). The bone grafting included Cem-OsteticTM 3 cases, autograft 17 and allograft 10 cases. The visual analogue scale (VAS) score and imageology changing were followed up.Results:All patients were follow-up for 12-24 months (average,18 months). Pre-operation, one week postoperatively and final follow-up, the average anterior height of vertebral body were 15.5±3.8mm,23.3±5.7mm and 22.5±5.1mm; and the average posterior height of vertebral body were 25.8±3.4mm,28.6±2.0mm and 28.3±2.2mm; the average Cobb angle were 23.5°±7.6°, 14.3°±7.1°and 15.7°±7.5°. The average VAS score were 7.57±1.45,2.57±0.65 and 2.07±0.62. All indexes above were significantly improved, there was a statistically significant difference between pre-operation and on week postoperatively (P<0.05), but no significant difference between final follow-up and 1 week postoperatively (P>0.05). All patients were cured and instrumentations were not loosed and broken. The bone mineral density of all fractured vertebral bodies was equal or higher than the adjacent levels.Conclusion:For restoring and maintaining the height of vertebral body and improving the density of the vertebral body, the posterior instrumentation combined with the vertebral lifted bone grafting is an ideal method to treat thoracolumbar fractures, especially for stability of the anterior and middle column of vertebral body.Chapter 2 Posterior paraspinal muscle approach for thoracic and lumbar spine fractures: compareed with the traditional surgical approachObjective:To evaluate the posterior paraspinal muscle approach treatment of thoracic and lumbar spine fractures (T2-L5) of the surgical methods and compared with conventional approach.Method:From October 2006 to October 2008,a total of 52 cases of non-neurological symptoms consecutive patients with thoracic and lumbar spine fractures were included in the study, including 37 male and 15 female with an average 46.5 years(from 18 to 59 years). Accordding to the Denis fracture classification, there were 17 compression fractures and 35 burst fractures with spinal space-occupying less than 1/3,including 1 T4 fractures,2 T7 fractures,1 Tg fractures,3 T10 fractures,5 T11 fractures,14 T12 fractures,16 L1 fractures,9 L2 fractures,1 L3 fractures. The patients are randomly divided in two group,20 cases with the traditional approach, and the other 32 cases with the posterior paraspinal muscle approach. All the patients were given pedicle screw fixation, partly with posterolateral fusion. Results:The posterior paraspinal muscle approach to the traditional after the surgery has no significant difference in time, but in the amount of bleeding, postoperative drainage, duration of recumbence and visual analogue pain score (VAS) significant advantages, the difference was statistically significant (P>0.05). All patients were follow-up for 9-24 months (average,15.6 months).Till the last follow-up, all patients with vertebral fractures were healed. No loosening or breaking of internal fixation.Conclusions:The posterior paraspinal muscle approach for thoracic and lumbar spine fractures, retain the posterior ligament complex, is an effective and minimally invasive treatment, with less trauma, less bleeding, the advantages of reliable clinical results.Chapter 3 Self-designed adjustable kyphoplasty device for a biomechanics testObjective:To develop a new type of titanium alloy adjustable kyphoplasty devices used to explore the feasibility of the vertebral reconstruction.Methods:Using of the rigid and flexible of titanium alloy, the equipment is composed of lantern-shaped metal pieces. Using the adjustable rotating precession devices to make the metal balls expansion and retraction, the device for vertebral reconstruction in the fresh human body of thoracolumbar spine specimens (T12-L2) for a feasibility test. Applications INSTRON5544 test the maximum stress load of metal balls by self-designed test equipment.Results:The initial diameter of lantern-shaped metal ball was 6.0mm, which formed from the titanium alloy, can pass the thoracolumbar pedicle channels into the vertebral body inside, and then rotating the adjustable device to adjust the metal ball to expanse, which reached maximum diameter was 12mm, while producing a strong distraction force, the biomechanical testing show that the maximum stress load of a single piece was 56.96±3.21N, the stress is 9.48±0.53 Mpa.Conclusion:The Self-designed adjustable kyphoplasty device can combinated with PKP or combinated with posterior pedicle screw fixation for the treatment of various types of fractures, including osteoporotic vertebral compression fractures, complete vertebral reconstruction. But its clinical application still need further study.SUMMARY1. To use the CT scanning and computer-aided technique to measure the related-lines and angles of the fresh human thoracic spine specimens (T10-L2). Through the measurement of the sagittal plane angle we have found that through the pedicle channels can be achieved the reduction of the endplate. At the same time, to calculate the volume of the vertebral reconstructtion through the pedicle channel, to provides a theoretical basis for the reduction of endplate and vertebral reconstruction.2. By simulating traumatic vertebral compression fractures, filled with allograft bone and bone cement through the pedicle channel to test biomechanical properties in the state of the integrity, damage and injuries immediately after the reconstruction. We confirmed that two different filling materials can be effectively maintain the reduction of vertebral injury, which has the same biomechanical properties of the integrity vertebral body.3. By filling with the different graft material to the sheep vertebral bone defect, which confirmed that in the blank control group the fibrous connective tissue structure can be seen, and none of trabecular bone structure. The trabecular bone, osteoblasts and osteoclasts can be seen at the junction of normal trabeculae and defect area; The defects in the sheep allogeneic bone group absorbed significantly, there are a large number of osteoblasts and trabeculae bone, which arranged in a certain direction; In acrylic bone cement group, the cement-trabecular bone interface shows a large number of defects and scattered pink dye homogeneous structure without any cellexistence, surrounded by a large number of inflammatory cells; The defects in the Cem-OsteticTM artificial bone group can be seen scattered trabeculae, surrounded by a large number of osteoblasts and osteoclasts, including a part of remodeling trabecular bone.4. Posterior pedicle screw fixation combined with vertebral body lifted, which can effectively replace endplate, restore vertebral height and angle, filled with different bone graft materials to maintain reduction and biomechanical properties, has a simple and economical features, which is improved based on the traditional surgical treatment and provided a new surgical option of the surgical treatment of thoracic and lumbar fractures.5. Compared with traditional surgical approach, the posterior paraspinal muscle approach retains the integrity of posterior ligament complex, greatly reducing the surgical trauma and shorten the operation time. Operating under direct vision surgery, without a large amount of X-ray fluoroscopy, and has the same surgical level, which compared with percutaneous minimally invasive surgery, is less than percutaneous pedicle screw system at the facet of the cost, operation time and the learning curve, has great relevance. This surgical approach provide a minimally invasive treatment for vertebral fractures from T1 to L5, which is confirmed by the anatomy and clinical research.6. The self-designed and developed by adjustable kyphoplasty devices and biomechanics test in vitro study confirmed that the device in the treatment of vertebral fractures of vertebral reconstruction is feasible and safe, which is simple operation, can be reused, saving the cost of surgery. Its can be applied to vertebral reconstruction in percutaneous or combination with pedicle screw fixation in the treatment of various types of vertebral fractures, including osteoporotic vertebral compression fractures.更多还原