经伤椎椎弓根螺钉固定联合经伤椎椎弓根植骨治疗胸腰椎骨折的效果观察
谢清华 陈忠羡 付兆宗 刘一涛 薛忠林
广东省江门市中心医院脊柱骨科,广东江门 529000
[摘要]目的探讨经伤椎椎弓根钉固定联合经伤椎椎弓根椎体内植骨治疗胸腰椎骨折的效果。方法回顾性分析我院2011年9月~2015年8月收治的109例胸腰椎骨折患者,根据治疗方法的不同分为A组(49例)和B组(60例)。A组采用单纯经伤椎椎弓根钉固定,B组采用经伤椎椎弓根钉固定联合经伤椎椎弓根椎体内植骨。术后随访8~29个月,平均随访15.1个月。比较两组术前、术后及末次随访数字射线摄影(DR)侧位片上测量的伤椎前缘高度压缩比、伤椎相邻椎Cobb角,记录两组的手术时间、手术出血量及手术并发症。结果B组的手术时间长于A组,出血量多于A组,差异有统计学意义(P<0.05)。两组术后及末次随访的伤椎前缘高度压缩比大于术前,Cobb角小于术前,差异有统计学意义(P<0.05)。A组末次随访的伤椎前缘高度压缩比小于术后,Cobb角大于术后,差异有统计学意义(P<0.05)。B组末次随访的伤椎前缘高度压缩比、Cobb角与术后比较,差异无统计学意义(P>0.05)。两组术前、术后的伤椎前缘高度压缩比、Cobb角比较,差异无统计学意义(P>0.05)。B组末次随访的伤椎前缘高度压缩比大于A组,Cobb角小于A组,差异有统计学意义(P<0.05)。A组有1例断钉,1例螺钉松动椎体高度后凸角度丢失,出现神经压迫症状需再次手术;B组无螺钉松动、无断钉。结论在胸腰椎骨折经伤椎椎弓根钉固定联合经伤椎椎弓根椎体内植骨治疗术中,经伤椎置钉可较好地恢复椎体高度,纠正后凸畸形角度;同时联合经伤椎弓根椎体内植骨,可减少远期螺钉松动、断钉及椎体高度、Cobb角丢失等并发症。
[关键词]胸腰椎骨折;伤椎;固定;椎弓根钉;植骨
胸腰椎骨折是脊柱损伤中的临床常见疾病,主要表现为骨折椎体压缩变扁,椎体高度丢失,椎体后凸畸形,骨折块突入椎管,压迫脊髓、神经。后路椎弓根钉系统复位固定术是治疗胸腰椎骨折最常见的治疗方法,近年来经伤椎椎弓根置钉复位内固定术报道较多,但单纯经伤椎椎弓根置钉复位内固定后,伤椎会出现“鸡蛋壳”效应,容易出现椎体高度、后凸角丢失及松钉、断钉等现象,影响手术效果。本研究选取我科收治的胸腰椎骨折患者作为研究对象,分别采用单纯经伤椎椎弓根钉固定与经伤椎椎弓根钉固定联合经伤椎椎弓根椎体内植骨治疗,探讨其效果,现报道如下。
1 资料与方法
1.1 一般资料
选取我院2011年9月~2015年8月收治的109例胸腰椎骨折患者,年龄18~70岁;其中交通事故68例,高处跌伤35例,重物砸伤6例;损伤节段:胸椎46例,腰椎63例;伤椎骨折类型(Denis分型):压缩性骨折38例,爆裂性骨折71例。所有患者均于伤后2 d内行X线检查、CT扫描、MR检查,以了解骨折部位、类型及有无骨折块突入椎管及脊髓受压程度,影像学显示双侧或至少一侧椎弓根完整,椎体压缩>30%。根据治疗方法的不同将入选患者分为A组 (49例)和B组(60例)。全部患者于伤后 3~10 d(平均 5 d)内进行手术。排除标准:骨折合并脱位;屈曲牵张型(三柱骨折);有严重脊髓神经损伤、合并其他部位严重骨折或重要要脏器损伤以及既往有脊柱手术史者;陈旧性骨折;肿瘤、结核。
1.2 手术方法
两组皆行气管插管全身麻醉,取俯卧位,腹部悬空,全身麻醉下取后正中切口,逐层切开,骨膜下分离两侧椎旁肌,显露伤椎及伤椎上下椎至两侧小关节突。
A组采用单纯经伤椎椎弓根钉固定,在C形臂X线机透视监测下,于伤椎及伤椎上、下椎体椎弓根内置入6枚椎弓根螺钉,有神经损伤表现者或明显脊髓压迫者可根据具体情况行椎板或半椎板切除,无明显脊髓压迫及神经损伤患者可无需减压,安装连接杆进行复位操作,C形臂X线机透视见复位满意后,检查固定牢固、复位良好后,冲洗伤口,置负压引流,关闭伤口。
B组采用经伤椎椎弓根钉固定联合经伤椎椎弓根椎体内植骨,在C形臂X线机透视监测下,于伤椎上、下椎体椎弓根内置入4枚椎弓根螺钉,同时伤椎经双侧椎弓根锥好置钉通道,有神经损伤表现者或明显脊髓压迫者可根据具体情况行椎板或半椎板切除,无明显脊髓压迫及神经损伤患者可无需减压,先行一侧伤椎椎弓根钉植入,安装连接杆进行复位操作,C形臂X线机透视见复位满意后,植入已切除的椎板和棘突,或取同种异体骨粒植入,填满为止,置入椎弓根钉,安放连接杆固定,检查固定牢固、复位良好后,冲洗伤口,置负压引流,关闭伤口。
1.3 术后处理
术后常规使用抗生素、对症等治疗,手术后24~72 h拔除引流管,拔管后进行下肢功能锻炼,功能恢复良好者术后7 d在支具保护下下地行走。
1.4 疗效观察
记录手术时间和术中出血量,统计分析手术前后腰椎正侧位片伤椎前缘高度压缩比值、Cobb角,并于随访时观察伤椎前缘高度复位丢失、植骨融合及并发症情况。所有患者手术前均行X线正侧位片及CT检查或MRI检查,术后行X线片或CT检查。
X线检查:观察骨折椎体有无变形,术前、术后测量椎体前缘高度,计算伤椎前缘高度与正常椎体前缘高度比值,前缘高度比值(%)=伤椎前缘高度/[(伤椎相邻上一椎体前缘高度+伤椎相邻下一椎体前缘高度)/2]×100%;记录椎体骨折融合情况,同时测量脊柱Cobb角。
CT或MR检查:术前CT观察椎体骨折压缩程度及终板是否骨折塌陷、爆裂骨折骨折块突入椎管的程度,MR检查明确脊髓、神经损伤情况,确定是否需要椎板切除减压。术后CT观察伤椎植骨融合情况。
1.5 统计学处理
采用SPSS 13.0统计学软件对数据进行研究,计量资料采用均数±标准差(±s)表示,采用 t检验,以P<0.05为差异有统计学意义。
2 结果
两组患者均获随访,时间8~29个月,平均随访15.1个月。B组的手术时间长于A组,出血量多于A组,差异有统计学意义(P<0.05)。两组术后及末次随访的伤椎前缘高度压缩比大于术前,Cobb角小于术前,差异有统计学意义(P<0.05)。A组末次随访的伤椎前缘高度压缩比小于术后,Cobb角大于术后,差异有统计学意义(P<0.05)。B组末次随访的伤椎前缘高度压缩比、Cobb角与术后比较,差异无统计学意义(P>0.05)。两组术前、术后的伤椎前缘高度压缩比、Cobb角比较,差异无统计学意义(P>0.05)。 B 组末次随访的伤椎前缘高度压缩比大于A组,Cobb角小于 A 组,差异有统计学意义(P<0.05)(表1)。A 组有1例断钉,1例螺钉松动椎体高度后凸角度丢失,出现神经压迫症状需再次手术;B组无螺钉松动、无断钉。
表1 两组相关指标测量结果的比较(±s)

 
与 A 组比较,*P<0.05;与同组术前比较,#P<0.05;与同组术后比较,P<0.05
3 讨论
3.1 经伤椎置钉对伤椎复位的作用
胸腰椎骨折是脊柱骨折最常见的外科疾病,后路跨伤椎4钉内固定技术已被广泛应用于临床,但其术后继发后凸畸形伤椎高度丢失现象时有报道。随着内固定技术的进步,有学者尝试三椎体(经伤椎椎弓根置钉)6钉内固定技术[1-3],其较跨伤椎4钉内固定技术具有固定更牢固可靠、矫正度丢失少等优点。跨节段4钉内固定技术是通过纵向撑开使前后纵韧带牵张及椎间盘牵拉,进而使压缩椎体复位。但如果前韧带或后韧带断裂及椎间盘撕裂,纵向撑开就不能使前后纵韧带达到牵张及椎间盘的牵拉作用,骨折椎体复位可能不理想。经伤椎椎弓根钉可直接撬拔终板,使椎体高度恢复,同时在复位时伤椎椎弓根螺钉可直接顶推、撑开复位椎体,有利于Cobb角度的矫正。杜心如等[4]认为,伤椎椎弓根钉对伤椎有直接的撬拨复位作用,同时能够纠正后凸畸形,减少骨折块对椎管的占位。Anekstein等[5]则认为,通过伤椎置钉可以克服伤椎的“悬挂”效应,使得伤椎也能承受和传递载荷,实现更均衡的载荷分享。对于脊柱后路结构而言,伤椎置钉可维持伤椎椎弓根与关节突和横突的连续性。俞阳等[6]研究比较经伤椎与跨伤椎椎弓根螺钉复位固定治疗胸腰椎骨折的临床效果,结果显示,应用经伤椎椎弓根螺钉有利于恢复伤椎前缘高度及矫正后凸畸形,减少伤椎高度的丢失以及增加脊柱的稳定性。本研究结果也显示,应用伤椎椎弓根螺钉内固定较不伤椎椎弓根螺钉内固定能更好地恢复椎体前缘高度,对骨折块有较好的复位作用,对后凸角有理想的矫正。
3.2 经伤椎置钉的生物力学特点
经伤椎椎弓根钉不仅可较好地恢复椎体的高度、Cobb角度,还能更好地改善生物力学。Hirano等[7]的研究显示,椎弓根提供了至少60%的拔出力强度及80%的轴向刚度,其余的15%~20%抗拔出力和轴向强度由椎体提供。Dick等[8]利用小牛胸腰椎模型行生物力学测试,结果显示6钉固定在轴向压缩、屈伸、扭转等方面的稳定性与4钉相比均有显著优势。吕夫新等[9]利用新鲜小牛胸腰椎脊柱标本制造成严重前中柱损伤模型,研究3种内固定方式的生物力学,结果显示6钉固定(经伤椎置钉固定)与8钉固定对失稳脊柱各方向稳定性的加强程度较为接近,均高于4钉内固定形式。Mathar等[3]在人的脊柱标本上进行生物力学测试,结果显示经伤椎椎弓根钉内固定较传统后路短节段跨伤椎内固定能增加脊柱的生物力学稳定性、脊柱固定复位后的固定及后凸畸形的矫正。
3.3 经椎弓根椎体内植骨的必要性
胸腰椎椎体骨折后,椎体内骨小梁支架结构遭到破坏,后路经伤椎椎弓根钉可较好地恢复伤椎高度,改善内固定的生物力学情况;但由于椎体充分复位后,椎体内骨小梁结构并未同时恢复,致使椎体呈空壳样变。胡海刚等[10]的研究显示,胸腰椎骨折复位术后出现椎体“空壳现象”发生率高达62.1%。有学者[11-16]认为,胸腰椎骨折经伤椎弓根钉内固定时需行经椎弓根椎体内植骨,其目的在于植入骨颗粒可达到填充、增强椎体支撑的作用,避免“蛋壳效应”发生,重建前中柱稳定性,植入骨颗粒能够起到骨诱导、骨支架作用,骨折愈合效果好,远期可达到防止椎体高度丢失的作用。孔维清等[17]通过63例胸腰椎骨折经椎弓根植骨组与不植骨组对照研究发现,经椎弓根植骨组较不植骨组能更好地维持伤椎高度及后凸角度,两组比较差异有统计学意义(P<0.05),且经椎弓根植骨组术后的伤椎骨密度和JOA评分明显高于后者。本研究结果也显示,经伤椎椎弓根椎体内植骨组较非植骨组能较好地维持椎体前缘高度及后凸角度,较少发生螺钉松动、断钉棒等并发症。笔者认为,经椎弓根椎体内植骨可填充复位后椎体内的空壳,植骨颗粒早期可起前路支撑作用,同时骨折愈合中起骨的生长支架作用,促进骨折愈合,减少远期椎体高度丢失及后凸畸形加重等并发症。
综上所述,经伤椎椎置钉可较好地恢复椎体高度,纠正后凸畸形角度;同时联合经伤椎弓根椎体内植骨术,可填充复位后椎体内的空隙,植骨颗粒早期可起到前路支撑作用,促进骨折愈合,减少远期螺钉松动、断钉及椎体高度、Cobb角丢失等并发症。
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Effect observation of pedicle screw fixation combined with transpedicular bone grafting in the treatment of thoracolumbar fractures
XIE Qing-hua CHEN Zhong-xian FU Zhao-zong LIU Yi-tao XUE Zhong-lin
Department of Spinal Orthopaedics,Central Hospital of Jiangmen City in Guangdong Province,Jiangmen 529000,China
[Abstract]Objective To explore the clinical efficacy of pedicle screw fixation combined with transpedicular bone grafting in the treatment of thoracolumbar fractures.Methods Clinical data of 109 cases with thoracolumbar fracture from September 2011 to August 2015 in our hospital were retrospectively analyzed,all patients were divided into group A(49 cases)and group B (60 cases)according to different treatment methods.Group A was treated with simple pedicle screw fixation,and group B was treated with the pedicle screw fixation of the fractured vertebra combined with transpedicular bone grafting of the injured vertebra.All patients were followed up for 8-29 months,the mean follow-up was 15.1 months.The compression ratio of the leading edge height of the injured vertebra,the adjacent vertebral Cobb angle in digital radiography (DR)preoperative,postoperative and final follow-up in the two groups were compared.Operation time,blood loss and complications in the two groups were recorded.Results The operation time of group B was longer than that of group A,and the amount of bleeding of group B was more than that of group A,with significant difference(P<0.05).The compression ratio of the leading edge height of the injured vertebra after operation and final follow-up of the two groups was greater than that before operation,and the angle of Cobb after operation and final follow-up of the two groups was smaller than that before operation,with significant difference(P<0.05).The compression ratio of the leading edge height of the injured vertebra final follow-up of group A was smaller than that after operation,and the angle of Cobb final follow-up of group A was greater than that after operation,with significant difference (P<0.05).There was no significant difference in the compression ratio of the leading edge height of the injured vertebra and the angle of Cobb of group B between final follow-up and after operation (P>0.05).There was no significant difference in the compression ratio of the leading edge height of the injured vertebra and the angle of Cobb before operation and after operation between the two groups(P>0.05).The compression ratio of the leading edge height of the injured vertebra final follow-up in group B was greater than that in group A,and the angle of Cobb final follow-up in group B was smaller than that of group A,with significant difference(P<0.05).1 case nail was broken in group A,and 1 case loss of height of the vertebral column in group A,with symptoms of nerve compression and needed reoperation.There is no broken nail and loss of height of the vertebral column in group B.Conclusion In pedicle screw fixation combined with transpedicular bone grafting,the pedicle screw can effectively restore vertebral height,correct kyphosis angle;at the same time,combined with transpedicular bone grafting can reduce the complications such as long-term screw loosening,broken nail and vertebral height,Cobb angle loss and so on.
[Key words]Thoracolumbar fracture;Vertebral injury;Fixation;Pedicle screw;Bone graft
[中图分类号]R683.2
[文献标识码]A
[文章编号]1674-4721(2017)10(a)-0107-04
(收稿日期:2017-03-28 本文编辑:祁海文)