短节段椎弓根螺钉置入内固定椎体成形治疗胸腰椎骨折的生物力学检测☆

背景：为避免单纯椎弓根螺钉置入内固定治疗胸腰段骨折出现的内固定物松动、断裂,及合并植骨时出现的骨折不愈合、后凸畸形丢失,而发展的短节段椎弓根螺钉合并椎体成形技术治疗胸腰段骨折,临床已有应用,但其生物力学方面鲜有研究。 目的：观察应用椎弓根螺钉置入内固定椎体成形治疗胸腰椎骨折的生物力学变化。 方法：12个冻存的新鲜胸腰段脊椎(T12~L2)标本,用于制备胸腰椎骨折模型,备测试。分为3组,经皮椎体成形术组：给予经单侧椎弓根注入低黏度的含对比剂骨水泥5~7 mL;椎弓根螺钉内固定组：于T12、L2椎弓根置入螺钉;强化组：行椎弓根螺钉内固定的同时行伤椎骨水泥椎体成形术,测试各组静态最大抗压强度及刚度。 结果与结论：骨水泥分布面积皆大于50%,经皮椎体成形术组和椎弓根螺钉内固定组最大静态抗压强度与刚度均小于强化组最大强度和刚度(P < 0.05)。椎弓根螺钉内固定组椎弓根螺钉较小强度下出现弯曲,而强化组在达到极性轴向压缩强度时才出现弯曲。提示应用短节段椎弓根钉置入内固定椎体成形治疗胸腰椎骨折提高了固定的强度及刚度,并且维持了复位伤椎高度,提高了稳定性,减少了椎弓根螺钉的并发症。     

经伤椎椎弓根螺钉置入内固定治疗胸腰椎骨折

目的：评价经伤椎椎弓根钉内固定治疗胸腰椎骨折的效果及不良反应。 方法：以胸腰椎、骨折、伤椎、椎弓根螺钉、内固定为中文关键词;以thoracolumbar,fracture,Injury vertebral,Pedicle screws,Internal fixation为英文关键词,采用计算机检索1993-01/2009-10相关文章。纳入与有关经伤椎椎弓根钉内固定治疗胸腰椎骨折相关的文章;排除重复研究或Meta分析类文章。以22篇文献为主重点讨论经伤椎椎弓根钉内固定治疗胸腰椎骨折的临床效果及不良反应。 结果：经伤椎椎弓根螺钉内固定能让胸腰骨折获得满意复位,重建椎体高度,增强脊柱的抗压稳定性,提供脊柱的长期稳定;既可有效的使胸腰椎骨折良好复位,牢固固定,又可减少内固定的松动或断裂,减少后凸的形成等内固定并发症;生物力学测试证明胸腰椎骨折伤椎椎弓根内固定能加强脊柱的稳定性;临床应用表明伤椎椎弓根内固定在技术操作上是可行的,选择合适、可靠的内固定物及工具,规范、严格地手术操作,不良反应会降低。 结论：经伤椎椎弓根螺钉内固定是治疗胸腰椎骨折的可靠、有效方法,且不良反应低。     

无神经症状单节段胸腰椎爆裂型骨折行后路短节段椎弓根螺钉内固定置入186例

背景：胸腰椎骨折治疗方法众多,但是对于无神经症状的爆裂型骨折,采用简单的手术方法治疗,是否在减少创伤的同时能够取得较好的疗效,从而避免手术的扩大化尚不清楚。 目的：观察采用单纯后路短节段椎弓根螺钉系统置入治疗无神经症状的单节段胸腰椎爆裂型骨折的疗效。 方法：选择2003-09/2008-01苏州大学附属第一医院骨科收治的无神经症状单节段胸腰椎爆裂型骨折患者186例,男152例,女34例,年龄18~65岁。均采用单纯后路短节段椎弓根螺钉内固定置入治疗,椎管内骨块占位采用间接复位。于置入前、置入后及置入后1年余取内固定前摄以伤椎为中心的X射线正侧位片和CT,对X射线平片和CT进行测量,统计伤椎前缘高度、伤椎横截面积内骨块的占有率。 结果与结论：伤椎前缘置入前高度平均为正常的42%,术后为98%,内固定取出术前伤椎前缘高度为正常高度的98%。伤椎横截面积内骨块占有率,术前平均为34%,术后平均为13%,内固定取出术前为8%。提示应用后路短节段椎弓根螺钉系统治疗无神经症状的胸腰椎爆裂型骨折,能够提供脊柱足够的稳定性,有效恢复椎体高度、生理弧度和椎管容积。     

个体优化经椎弓根置钉复位内固定治疗胸腰椎骨折

背景：在日臻成熟的椎弓根螺钉应用技术中,仅满足于将螺钉置入椎弓根中是不够的,而是应根据骨折复位固定要求寻求最佳置钉通道。 目的：验证经椎弓根内固定个体化治疗胸腰椎骨折的有效性和安全性。 方法：对50例胸腰椎骨折患者内固定前X射线片和CT片进行个体化矢状面及水平面椎弓根螺钉置入角、椎弓根横径、间距、钉道深度、椎体前后高、脊柱后凸角及椎管前后径测量,确定胸腰段椎弓根钉道个体优化置钉和复位的安全范围。术中结合解剖定位标志,C臂X射线机监控置钉并复位骨折椎体,确定复位结果。 结果与结论：置钉位置良好,角度及深度适中,内固定后骨折椎体复位高度、后凸角及椎管面积改善(P < 0.01)。经2~26个月随访,骨折均愈合。提示在胸腰段椎弓根钉道个体化影像测量安全范围内,优化置入椎弓根钉和复位是保证置钉内固定安全和椎体骨折复位合理而有效的方法。     

伤椎椎弓根固定治疗胸腰椎骨折33例分析

目的 探讨胸腰椎骨折经伤椎椎弓根直接复位内固定的可行性和疗效.方法 采用经伤椎椎弓根固定胸腰椎骨折33例,术前术后随访摄片观察椎体高度有无丢失,内固定物有无松动.结果 平均随访13.7个月,术前、术后伤椎椎体前缘高度比和Cobb角恢复良好,未出现内固定物松动和断裂.结论 胸腰椎骨折伤椎椎弓根固定有利于矫正后凸畸形,维持矫正效果,内固定系统固定牢固显著增强了脊柱的强度和稳定性.     

经椎弓根植骨结合Schanz钉治疗胸腰段椎体骨折脱位

目的探讨经椎弓根椎体内植骨结合后路Schanz钉内固定治疗胸腰段椎体骨折脱位的临床疗效。方法2004-03～2007—07应用Schanz钉复位固定及经患椎椎弓根内植骨治疗胸腰段椎体骨折脱位16例,受伤节段为T11～L2,通过测量术前、术后x线片了解骨折椎体前缘变化,随访后期相关并发症情况。结果全部患者随访6～36个月,平均18个月。14例患者骨折椎体前缘高度平均恢复92％,患者神经功能部分恢复3例,完全恢复5例,无后凸畸形,无内固定松动、拔出、断钉等并发症。结论经椎弓根植骨并使用Schanz钉治疗胸腰段椎体骨折脱位复位效果满意,操作方便,无明显并发症。     

后路椎弓根螺钉系统固定并颗粒型磷酸钙人工骨经伤椎椎弓根椎体内植骨治疗青壮年胸腰椎骨折30例随访

回顾性分析2006-11/2008-10上海交通大学附属上海市第六人民医院脊柱外科收治的胸腰椎骨折患者30例,男18例,女12例;年龄29～65岁;均为单椎体骨折,骨折节段为T12~L2;压缩性骨折18例,爆裂性骨折12例。均采用后路椎弓根螺钉系统固定加经伤椎椎弓根椎体内植骨。记录植入时间,植入过程中出血量及植入并发症;伤椎以及临椎骨密度;植入后摄标准髋关节正侧位X射线平片,并测量Cobb角变化。30例患者均获得随访,平均17.6个月。植入时间90~220 min,出血量150~1 100 mL。2例发生椎体前方渗漏现象,所有病例均未发生椎管内渗漏现象。全部患者植入过程中均无神经系统并发症及其他并发症发生。内固定去除后3个月QCT测量显示,所有伤椎骨皮质,松质骨密度都较之相邻椎体明显升高(P < 0.05)。术后Cobb角平均(4.08±0.87)°,较术前(28.15±0.24)°有明显改善,差异有显著性意义(P < 0.05),随访时(4.71±1.45)°无明显丢失(P > 0.05)。提示使用椎弓根螺钉系统治疗青壮年胸腰椎骨折同时使用颗粒型磷酸钙人工骨经伤椎的椎弓根行椎体内植骨成形可以有效填充椎体内骨缺损空腔,避免术后椎体高度的丢失,并增强伤椎的强度。     

内固定材料置入后路短节段椎弓根并伤椎椎弓根充填自体糊状髂骨治疗胸腰椎爆裂性骨折

选择2002-08/2006-07湘潭市第一人民医院采用后路短节段椎弓根内固定材料置入并伤椎椎弓根充填自体糊状髂骨治疗胸腰椎爆裂性骨折35例。①置入材料：RF-Ⅲ脊柱内固定器，TENOR脊柱内固定系统，AF脊柱内固定系统。②术者资质：施术者为本科从事脊柱外科专业工作的主任医师或副主任医师，术者资格符合岗位技术标准要求。③置入后材料与宿主的生物相容性随访：平均随访14.8个月, 未发生内置物断裂和螺钉松动现象,也无明显矫正度丢失现象；无炎症及排异现象发生。④骨折愈合情况：骨折均达到满意复位并愈合,伤椎高度均得到明显恢复。⑤神经功能恢复情况：神经功能不全损伤患者均有不同程度功能恢复。⑥结果提示：该内固定材料置入后与宿主的生物相容性较好，可以重建椎体高度,增加脊柱前柱的抗压稳定性,可有效地防止内固定失败和矫正度丢失。     

伤椎椎弓根置钉治疗胸腰椎压缩性骨折的三维有限元分析*

背景：有文献报道伤椎置钉技术较传统4钉跨阶段固定具有更强的牢固性,可有效避免内固定的松动断裂,但其生物力学机制研究尚显不足。 目的：构建脊柱胸腰椎单纯压缩性骨折的三维有限元模型,探讨伤椎附加椎弓根螺钉置入治疗胸腰椎压缩性骨折的生物力学效应。 方法：将一T12椎体压缩性骨折患者脊柱胸腰段超薄CT扫描数据输入Mimics软件中,构建T12椎体压缩性骨折的有限元模型,在此模型基础上模拟伤椎置6钉和跨节段4钉内固定,对两个模型分别施加垂直压缩、前屈、后伸、左屈及右旋载荷。 结果与结论：两组固定模式各种载荷下的应力均集中在螺钉根部,在垂直载荷下,螺钉的应力最小,右旋和左屈载荷下的应力最大;在垂直压缩、前屈、后伸、左侧弯及右旋运动下,上位螺钉较下位螺钉应力大(P < 0.05)。伤椎置6钉固定组螺钉应力较跨节段4钉固定组小(P < 0.05)。两组T11椎体最大位移无差别。表明伤椎附加椎弓根螺钉置入可以优化内固定的载荷,减少断钉率。     

经椎弓根植骨结合Schanz钉治疗胸腰段椎体骨折脱位

我院2003—05～2007—07采用经后路椎弓根植骨结合Schanz钉内固定治疗32例胸腰段椎体骨折脱位患者,结果表明胸腰段椎体骨折脱位的后遗症明显减少,患椎高度恢复满意,疗效可靠。     

Short Segment Fixation for Thoracolumbar Burst Fracture Accompanying Osteopenia : A Comparative Study

Objective

The purpose of this study was to compare the results of three types of short segment screw fixation for thoracolumbar burst fracture accompanying osteopenia.

Methods

The records of 70 patients who underwent short segment screw fixation for a thoracolumbar burst fracture accompanying osteopenia (-2.5< mean T score by bone mineral densitometry <-1.0) from January 2005 to January 2008 were reviewed. Patients were divided into three groups based on whether or not bone fusion and bone cement augmentation procedure 1) Group I (n=26) : short segment fixation with posterolateral bone fusion; 2) Group II (n=23) : bone cement augmented short segment fixation with posterolateral bone fusion; 3) Group III (n=21) : bone cement augmented, short segment percutaneous screw fixation without bone fusion. Clinical outcomes were assessed using a visual analogue scale and modified MacNab''s criteria. Radiological findings, including kyphotic angle and vertebral height, and procedure-related complications, such as screw loosening or pull-out, were analyzed.

Results

No significant difference in radiographic or clinical outcomes was noted between patients managed using the three different techniques at last follow up. However, Group I showed more correction loss of kyphotic deformities and vertebral height loss at final follow-up, and Group I had higher screw loosening and implant failure rates than Group II or III.

Conclusion

Bone cement augmented procedure can be an efficient and safe surgical techniques in terms of achieving better outcomes with minimal complications for thoracolumbar burst fracture accompanying osteopenia.     

椎弓根螺钉植入物断裂18例相关因素分析*

目的：分析胸腰椎骨折中椎弓根螺钉断裂的相关因素。 方法：选择2001-03/2008-03桂林医学院附属医院脊柱外科收治的胸腰段骨折行椎弓根钉内固定患者374例,其中使用不锈钢材料的246例,使用钛合金材料的128例。术后出现椎弓根钉断裂患者18例(实验组),男8例,女10例;年龄19~61岁,平均38.6岁。随机抽取18例具有可比性的未断钉治疗效果良好的患者进行对比(对照组),男9例,女9例;年龄21~57岁,平均37.5岁。阅读所有观察对象的脊柱正侧位片,测量病椎的椎间隙高度、椎弓钉位置,观察骨性融合程度和横杆使用情况。 结果：246例使用不锈钢材料的患者中12例发生断钉,断钉率4.88%。128例使用钛合金材料的患者6例发生断钉,断钉率4.69%。两者相比,差异无显著性意义(P > 0.05),提示椎弓根钉的断钉和其材料无明显关系。通过对实验组和对照组4个观察指标的分析,病椎椎间隙的高度与椎弓根钉的断钉无明显关系,但是椎弓根钉置入的位置、植入骨的骨性融合程度及是否使用横杆和椎弓根钉的断钉有明显关系。 结论：胸腰椎骨折中螺钉断裂与其材料性质无明显关系,与椎弓根钉位置﹑骨性融合程度、横杆使用等因素密切相关,是多因素共同作用的结果。     

Biomechanical effect of the extent of vertebral body fracture on the thoracolumbar spine with pedicle screw fixation: an in vitro study.

A fractured vertebra does not transfer load as effectively as the intact vertebra. Patients who undergo surgery using short-segment pedicle screw instrumentation for middle-column injury may experience implant failure when vertebral body comminution is ignored. The purpose of this study was to investigate biomechanical effects of the extent of vertebral body fracture on the thoracolumbar spine after pedicle screw fixation and to evaluate the biomechanical role of anterior reconstruction. Twelve fresh porcine T12-L3 specimens were harvested and divided into two groups. A 2-mm drill bit was used to create holes in the L1 vertebra with two different extents: 1/6 and 1/3 vertebral body involvement. After the pre-injury had been created, specimens were subjected to flexion-compression to create a fracture in the body of the spine. Stiffness under axial-compression and flexion-compression were measured in intact specimens, after the fractured segments had been stabilized using transpedicular fixation, and after transpedicular fixation with anterior grafting. Despite fixation of the injured spine with pedicle screw instrumentation, the axial-compression and flexion-compression stiffness was still significantly lower than that of the intact group (p<0.01). The stiffness was associated with the extent of vertebral body involvement; 1/6 vertebral body involvement was stiffer than the 1/3 involvement (p<0.01). Additional anterior grafting significantly improved stiffness compared with posterior fixation alone (p<0.01), and restored stiffness to the intact level. In any state, stiffness under axial-compression was always significantly greater than that under flexion-compression (p<0.01). In conclusion, transpedicular fixation alone cannot provide sufficient stability for thoracolumbar fractures; the construct stability is related to the extent of vertebral body involvement. Recovering mechanical properties of the anterior and middle spinal column is a valuable measure for reducing the load-sharing of the posterior instrument.     

后路经椎弓根病灶清除、自体及同种异体骨植骨融合并节段性内固定治疗

摘要：回顾性分析2006-01/2008-06中南大学湘雅医院脊柱外科收治的脊柱结核患者22例,男15例,女7例;年龄17~50岁。其中胸椎结核8例,胸腰段结核4例,腰椎结核10例。均以胸腰背部疼痛首诊,伴瘫痪症状者10例,Frankel分级B级3例,D级7例。影像学检查主要表现为椎体骨质破坏,椎间隙变窄或消失。椎旁脓肿形成者8例,14例患者有不同程度后凸畸形。入院时平均血沉55 mm/h,术前平均血沉35 mm/h。全部病例采用后路经椎弓根行病灶清除、自体骨和/或同种异体骨植骨融合、以及节段内固定术治疗,观察围手术期并发症;根据术前、术后1周,术后6个月侧位X射线平片测量融合节段Cobb角;评价植骨融合情况。本组无术中并发症,术后疼痛症状消失。术后1周平均血沉20 mm/h,术后1~3个月全部降至正常范围。22例患者随访6~14个月,术后6个月均获骨性融合,至终末随访时均无感染和结核复发,无内固定失败,全部患者结核治愈。10例伴有神经功能损害者末次随访时Frankel B级3例均恢复到D级,D级7例均恢复到E级。术后1周后凸Cobb角较术前减小[(12.7±7.1)°,(31.2±10.6)°,P < 0.05],术后6个月与术后1周差异无显著性意义[(12.9±7.3)°,(12.7±7.1)°,P > 0.05]。提示后路经椎弓根病灶清除、植骨内固定术是治疗胸腰椎结核行之有效的方法。     

Short Segment Screw Fixation without Fusion for Unstable Thoracolumbar and Lumbar Burst Fracture : A Prospective Study on Selective Consecutive Patients

Objective

The purpose of this prospective study was to evaluate the efficacy and safety of screw fixation without bone fusion for unstable thoracolumbar and lumbar burst fracture.

Methods

Nine patients younger than 40 years underwent screw fixation without bone fusion, following postural reduction using a soft roll at the involved vertebra, in cases of burst fracture. Their motor power was intact in spite of severe canal compromise. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The patients underwent removal of implants 12 months after the initial operation, due to possibility of implant failure. Imaging and clinical findings, including canal encroachment, vertebral height, clinical outcome, and complications were analyzed.

Results

Prior to surgery, the mean pain score (visual analogue scale) was 8.2, which decreased to 2.2 at 12 months after screw fixation. None of the patients complained of worsening of pain during 6 months after implant removal. All patients were graded as having excellent or good outcomes at 6 months after implant removal. The proportion of canal compromise at the fractured level improved from 55% to 35% at 12 months after surgery. The mean preoperative vertebral height loss was 45.3%, which improved to 20.6% at 6 months after implant removal. There were no neurological deficits related to neural injury. The improved vertebral height and canal compromise were maintained at 6 months after implant removal.

Conclusion

Short segment pedicle screw fixation, including fractured level itself, without bone fusion following postural reduction can be an effective and safe operative technique in the management of selected young patients suffering from unstable burst fracture.     

Implant Removal after Percutaneous Short Segment Fixation for Thoracolumbar Burst Fracture : Does It Preserve Motion?

Objective

The purpose of this study was to evaluate the efficacy of implant removal of percutaneous short segment fixation after vertebral fracture consolidation in terms of motion preservation.

Methods

Between May 2007 and January 2011, 44 patients underwent percutaneous short segment screw fixation due to a thoracolumbar burst fracture. Sixteen of these patients, who underwent implant removal 12 months after screw fixation, were enrolled in this study. Motor power was intact in all patients, despite significant vertebral height loss and canal compromise. The patients were divided into two groups by degree of osteoporosis : Group A (n=8), the non-osteoporotic group, and Group B (n=8), the osteoporotic group. Imaging and clinical findings including vertebral height loss, kyphotic angle, range of motion (ROM), and complications were analyzed.

Results

Significant pain relief was achieved in both groups at final follow-up versus preoperative values. In terms of vertebral height loss, both groups showed significant improvement at 12 months after screw fixation and restored vertebral height was maintained to final follow-up in spite of some correction loss. ROM (measured using Cobb''s method) in flexion and extension in Group A was 10.5° (19.5/9.0°) at last follow-up, and in Group B was 10.2° (18.8/8.6°) at last follow-up. Both groups showed marked improvement in ROM as compared with the screw fixation state, which was considered motionless.

Conclusion

Removal of percutaneous implants after vertebral fracture consolidation can be an effective treatment to preserve motion regardless of osteoporosis for thoracolumbar burst fractures.     

下颈椎弓根CT图像的指标测量

背景：由于颈椎弓根较小的周径,高度的个体差异,周围复杂的解剖结构,在置椎弓根螺钉时易误伤脊髓、椎动脉及神经根,临床应用受到限制。正确的理解椎弓根及其周围结构解剖特点有助于提高经椎弓根螺钉内固定操作的安全性。 目的：评价CT测量颈椎椎弓根在颈椎弓根内固定的临床意义。 方法：随机选择81例正常成人颈椎CT片进行颈椎骨性指标的研究,测量指标包括13项：椎弓根高度、宽度,椎弓根内侧、外侧、上缘、下缘皮质厚度,椎弓根内松质骨高度、宽度,椎弓根轴线的骨性通道全长,椎弓根的长度1、长度2,椎弓根的内倾角和椎弓根轴线在矢状面上与椎体下终板之间的角度。 结果与结论：椎弓根宽度小于高度,C3、C4外径最小,颈椎椎弓根的松质骨内径小,皮质骨比例高。外侧皮质骨较内侧和上、下侧皮质骨均薄。下颈椎椎弓根的三个通道长度变化不显著,内倾角和上下倾角则有一定区别。提示经螺旋CT可以较好的呈现椎弓根内部的情况,为颈椎弓根螺钉内固定提供影像学数据。     

经椎弓根椎体楔形截骨治疗胸腰椎陈旧性骨折伴后凸畸形23例

背景：迟发性创伤后胸腰椎后凸畸形常引起下腰痛及椎管骨性压迫。为了消除疼痛及改善神经功能,常需手术治疗,其目标是矫正畸形,稳定脊柱。但究竟采取何种手术入路仍存在争论。 目的：观察经椎弓根椎体楔形截骨治疗胸腰椎陈旧性骨折伴后凸畸形的疗效。 方法：回顾性分析2004-01/2006-12南华大学附属第一医院脊柱外科收治的胸腰椎陈旧性骨折并后凸畸形患者23例,男14例,女9例;年龄18~60岁,平均36岁;术前腰椎功能损伤程度按照JOA评分标准评定为(11.02±1.24)分,胸腰段后凸畸形Cobb角为(37.43±3.76)°。23例患者均采用经椎弓根椎体截骨、椎管减压及重建矢状面矫形方法,比较截骨前后腰椎功能恢复、骨愈合情况及有无并发症发生。 结果与结论：23例患者均获得随访,随访时间6~28个月,平均12.5个月。术后腰椎功能及后凸畸形均有明显改善,末次随访JOA评分为(14.04±2.12)分,Cobb角为(11.02±3.58)°,与术前相比差异均有显著性意义(P < 0.05)。截骨面均于术后6个月骨性愈合,无假关节形成及矫正丢失等并发症。提示经椎弓根椎体楔形截骨可获得满意的后凸畸形矫正和神经减压,可促使腰椎功能恢复。