下颈椎后路螺钉固定的生物力学研究进展

目前,下颈椎后路螺钉固定除侧块螺钉和椎弓根螺钉技术已普遍应用外,经关节螺钉和经椎板螺钉固定技术也逐渐被重视。本文就此介绍下颈椎后路4种螺钉固定方式,并对各自固定技术的生物力学研究现状进行综述。生物力学研究内容包括三维稳定性、抗拔出力、置钉技术和螺钉特点等。侧块螺钉和椎弓根螺钉技术,因其优越的三维稳定性和较强的抗拔出力,已经作为下颈椎不稳的一种有效固定方法。经关节螺钉固定作为一种新的下颈椎后路固定方法,具有广范的手术适应证,并且该技术相对安全、简易,临床上也取得了良好的疗效。经椎板螺钉固定技术临床应用不多,但通过解剖学和生物力学研究证实,该技术可成为临床上可行的补救技术。上述4种下颈椎后路螺钉固定技术,各有其优劣,临床应用也各不相同,通过对这些技术的生物力学研究,将有助于下颈椎后路螺钉内固定技术的发展,更有效的指导临床工作。     

C7后路棘突螺钉固定的解剖可行性研究

目的:测量成人C7棘突螺钉固定的可行性和解剖参数,为临床应用提供参考。方法:取20具C7标本,仔细解剖以清楚地暴露椎板和棘突。用游标卡尺测量解剖学数据,包括C7棘突根部1/2、棘突中部、棘突后部1/2的高度,C7棘突根部头侧1/2、棘突根部中缘、棘突根部尾侧1/2的中点厚度,钉道长度、钉尖至椎动脉孔及脊髓的距离。随机抽取100名正常成年人CT图像测量C7棘突相关数据。结果:所有棘突螺钉均成功置入C7棘突。C7棘突平均高度和厚度分别为(11.25±2.28)mm、(12.53±3.11)mm。螺钉钉道长度平均为(9.83±2.23)mm,钉尖与椎动脉、脊髓的距离分别为(6.88±1.31)mm、(22.53±3.73)mm。下位螺钉钉道长度平均为(11.42±2.64)mm,明显长于上位螺钉钉道长度的(8.24±1.82)mm,差异有统计学意义(P<0.01)。100名正常成年人的C7棘突CT测量值与手工测量值比较差异无统计学意义(P>0.05)。结论:C7棘突螺钉具有解剖学可行性,有可能作为C7后路固定的一种补充内固定方法。     

寰椎椎弓根螺钉及枢椎椎板螺钉固定植骨融合治疗创伤性上颈椎不稳

目的:探讨寰椎椎弓根螺钉及枢椎椎板螺钉固定、植骨融合治疗创伤性上颈椎不稳的临床疗效。方法:2005年10月至2008年6月,采用后路寰椎椎弓根螺钉及枢椎椎板螺钉或椎弓根螺钉固定技术治疗创伤性上颈椎不稳患者43例,其中枢椎椎板螺钉固定组(A组)21例,枢椎椎弓根螺钉固定组(B组)22例。所有患者均有寰枢椎半脱位或不稳,表现为不同程度的颈枕区疼痛,活动受限。均使用颈椎后路Vertex钉棒系统固定。对比两组的手术时间、术中出血量,有无神经、血管、脊髓损伤和内固定松动、断裂失败并发症,是否出现复位丢失和植骨融合率。结果:A组手术时间1～3h,平均1.5h,出血量100～650ml,平均240ml。B组手术时间1.2～3h,平均2h,出血量120～800ml,平均350ml。A组手术时间和术中出血量明显少于B组(P0.05)。A组有2例、B组有3例术中在剥离时损伤C1-2间静脉丛,均用明胶海绵压迫止血成功。术后CT显示B组1例单侧枢椎椎弓根螺钉部分进入横突孔,但无症状,余枢椎椎弓根螺钉和椎板螺钉均位置良好,未见椎动脉、神经损伤及脑脊液漏并发症。43例术后获12个月～3年随访,平均20.3个月,所有患者均于术后3～4个月获得骨性融合,术后X线片显示颈椎稳定,未见复位丢失,亦未见内固定松动退出或断裂。结论:对创伤性上颈椎不稳患者应用寰椎椎弓根螺钉及枢椎椎板螺钉固定不仅具有椎弓根螺钉同等的固定疗效,而且相对安全、简单,可以作为椎弓根螺钉固定的一种补充方法。     

两种下颈椎经关节螺钉植入方法的比较研究

目的：比较两种下颈椎经关节螺钉植入方法的优缺点,提出并验证更为合理的植入方法,为临床提供参考。方法：运用8具颈椎标本随机模拟植入下颈椎经关节螺钉,植入的方法：一侧采用Takayasu法（记为A组）,另一侧采用Dalcanto法（记为B组）。A、B两组分别统计：植入时关节突关节劈裂情况;横突孔侵犯情况;植入后神经根损伤情况;未通过关节突关节的螺钉数。结果：共植入下颈椎经关节突螺钉64枚,A、B两组各32枚。A组未见下关节突劈裂;B组见下关节突关节下缘劈裂7例,外缘劈裂3例;两组中均未见上关节突劈裂。A组中发现8枚螺钉侵犯横突孔,B组未见横突孔侵犯。神经根前支损伤A组11例,B组2例;神经根后支损伤A组8例,B组9例。经观察证实A组2例未经过关节突关节,B组均经过下关节突关节。结论：Takayasu法在螺钉植入过长时易引起神经根和椎动脉损伤．而Dalcanto法在植入螺钉时易引起下关节突劈裂。     

下颈椎经关节螺钉固定“两点法”置钉的解剖学研究

目的通过解剖学研究,获得下颈椎经关节螺钉的安全置钉方法。方法取18具颈椎标本,仔细解剖颈部的后方和前侧方,以清楚地暴露颈椎侧块,保护好脊神经前、后支（C2～8）及与周围结构的关系。确定安全进、出钉：以侧块背面中心点内侧1mm为进钉点;下位椎体上关节突的侧前方,横突与关节突相交处为出钉点。从C2/C3～C5/C6直视下通过以上2点置入克氏针,通过正侧位X线片测量克氏针在矢状面上的尾倾角、在冠状面上的外倾角及进钉深度,以确定经关节螺钉固定的进钉角度和螺钉长度,并测量经关节螺钉出钉点与脊神经前、后支和椎动脉的距离。结果实验中所有克氏针均成功置入。经关节螺钉的外倾角度为16.5°±5.1°,尾倾角度为36.6°±5.1°,钉道长度为19.0mm±1.2mm。经关节螺钉的外倾角度和尾倾角度在各节段间略有不同,但差异均无统计学意义（P〉0.05）,但钉道长度在C2/C3与C3/C4/C5/C6间差异有统计学意义（P〈0.05）。经关节螺钉出钉点与脊神经前支距离为18.2mm±2.3mm,与后支距离为7.3mm±1.4mm,与椎动脉距离为5.8mm±1.5mm,在各节段间略有不同,但差异均无统计学意义（P〉0.05）。结论使用下颈椎经关节螺钉固定技术时建议以侧块背侧中心点内侧1mm为进钉点,在矢状面上尾倾35°～40°,在冠状面上外倾15°～20°,尽量将螺钉从下位椎体上关节突的侧前方、横突后嵴与关节突连接处出钉。     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

枢椎棘突、椎板和椎弓根的CT测量

目的探讨CT测量枢椎棘突、椎板和椎弓根的临床疗效及其临床意义。方法自2011年2月~2011年10月使用多层螺旋CT扫描机进行枢椎扫描,测量枢椎棘突基底部宽度和棘突中段高度、枢椎椎板中段的宽度和高度、枢椎椎弓根中段的宽度和高度。结果枢椎棘突基底部宽度、椎板中段宽度和椎弓根中段宽度测量结果分别为(19.57±2.11)、(6.12±1.23)、(5.82±1.39)mm,枢椎棘突宽度明显大于椎板和椎弓根,差异有统计学意义(P0.05)。枢椎棘突、椎板和椎弓根中段的高度测量结果分别为(13.13±2.06)、(12.63±1.91)、(5.73±1.25)mm,枢椎棘突和椎板中段的高度明显大于椎弓根,差异有统计学意义(P0.05)。结论枢椎棘突具有枢椎椎板和椎弓根具有更大的置钉空间,枢椎棘突螺钉也可以作为一种补充内固定的方法。     

TLIF与PLIF治疗腰椎退行性疾病疗效的Meta分析

目的:对TLIF与PLIF治疗腰椎退行性疾病的疗效及并发症进行Meta分析.方法:检索Medline、Ovid、中国生物医学文献数据库系统(CBM)、中国期刊全文数据库(CNKI)、中文科技期刊全文数据库(VIP)等数据库,检索时间至2012年5月.本研究提取的评价指标包括手术时间、手术失血量、住院时间、视觉模拟评分(visual analogue scale,VAS)、Oswestry功能残障指数(Oswestry disability index,ODI)等指标和并发症例数.应用Review Manager 5.1软件进行数据分析.结果:纳入文献9篇,其中随机对照研究1篇,队列研究8篇.共981例,TLIF组457例,PLIF组524例.两组间比较,手术失血量(P=0.002)及住院时间(P=0.02)TLIF组少于PLIF组,而优良例数(P＝0.27)、手术时间(P=0.07)、VAS评分(P＝0.61)和ODI评分(P＝0.24)两组间无差异;总并发症两组间差异显著(P＜0.0001),其中神经损伤(P=0.001)、硬膜损伤(P=0.04)TLIF组较少,而脑脊液漏(P=0.25)、螺钉松动(P=0.14)、内固定失败(P=0.86)、未融合例数(P=0.41)和感染(P=0.51)两组间无显著性差异.结论:两者临床总疗效优良率相当,但TLIF手术在手术失血量、住院时间及术后并发症方面,尤其是对神经和硬膜的损伤,较PLIF明显减少.TLIF手术是一种更安全有效地治疗腰椎退行性疾病的方法.