下颈椎前路椎弓根螺钉内固定技术的研究进展

与传统前路和后路手术相比,下颈椎前路椎弓根螺钉内固定技术（anterior transpedicular screw fixation．ATPS）具有较好的生物力学优势、相对安全等特点,仅通过一次前路手术可解决减压和重建两个问题。但是由于ATPS采用了较为特殊的解剖通道,临床上暂无专门用于前路椎弓根螺钉置钉的配套内固定系统,下颈椎ATPS技术的适应证相对较窄,尚不能替代传统前路和后路手术方法。如何精确置钉以及ATPS相关内固定器械的开发是目前研究的热点及未来发展方向。     

颈椎经关节椎弓根螺钉固定与标准椎弓根螺钉固定的生物力学比较

目的 比较颈椎经关节椎弓根螺钉固定和标准椎弓根螺钉固定的拔出强度.方法 取10具新鲜尸体颈椎标本(C_3～T_1),游离成三个颈椎运动节段(C_(3,4),C_(5,6),C_7T_1).在椎体两侧随机进行经关节椎弓根螺钉固定或标准椎弓根螺钉固定,置入直径3.5 mm皮质骨螺钉.经关节椎弓根螺钉固定以上位椎骨侧块外下象限中点为进钉点,在直视椎弓根下,螺钉在冠状面内倾约45°、矢状面尾倾约50°.由上位椎骨下关节突经关节突关节、下位椎骨的椎弓根,进入下位椎骨的椎体内.标准椎弓根螺钉固定以侧块外上象限中点为进钉点,在直视椎弓根下,螺钉方向参考CT测量结果 ,尽量与椎弓根倾斜角度保持一致,在横断面上内倾约45°、矢状面上螺钉指向椎体的上1/3.在生物力学试验机上行拔出强度试验,比较两种螺钉固定的最大轴向拔出力.结果 颈椎经关节椎弓根螺钉固定平均最大轴向拨出力为(694±42)N,标准椎弓根螺钉固定为(670±36)N,两者比较差异有统计学意义(P<0.05).结论 颈椎后路经关节椎弓根螺钉固定的拔出强度大干标准椎弓根螺钉固定,从生物力学强度方面考虑经关节椎弓根螺钉固定可以作为标准椎弓根螺钉固定的一种补充方法.     

颈椎经关节椎弓根螺钉固定与标准椎弓根螺钉固定的生物力学比较

Objective To compare biomechanical pullout strength of cervical transfacet pedicle screws to that of standard pedicle screws. Methods Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3,4, C5,6, and C7T1 levels. On the other side, pedicle screws were, placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was about located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50° caudally in the sagittal plane and about 45° medially in the axial plane. Screws were placed across the facet joint and the pedicle into the body of the caudal vertebra. The entry points for pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass and the direction of the screw was about 45° toward the midline in the transverse plane and toward the upper third of the vertebral body in the sagittal plane. The pedicle screws were oriented along the axis of the pedicle in an effort to avoid violations of the cortical wall. All the screw insertions were based on direct observation and the CT scan on the pedicles. After screw placement, axial pullout testing was performed. Results The mean pullout strength for the transfacet pedicle screws was (694±42) N. This compares with (670±36) N for the pedicle screws (P< 0.05). The greatest difference at a single level in pullout strength was observed at the C5,6 level, with a mean difference of 38 N. Conclusion Transfacet pedicle screws exhibited statistically greater pullout strength to pedicle screws. At each level the transfacet pedicle screws exhibited greater pullout strength than the pedicle screws. Posterior transarticular pedicle screw fixation in the cervical spine affords an alternative to standard screw placement for plate fixation and cervical stabilization.     

下颈椎椎弓根螺钉内固定技术应用研究进展

低位颈椎(C3～7)亦称为下颈椎,其活动度较大且应力分布集中,为颈椎病好发部位.在脊柱内固定出现之前,颈椎病主要采用非手术治疗,包括药物、牵引、外固定器等.随着外科手术的发展和内固定器械的进步,侧块螺钉和椎弓根螺钉内固定技术的应用,为创伤性和非创伤性颈椎疾患的刚性内固定奠定了基础.椎弓根螺钉由于其独特的生物力学优势,越...     

下颈椎经椎弓根螺钉内固定相关解剖学观察

目的为下颈椎经椎弓根螺钉内固定提供应用解剖学基础及形态学资料。方法应用游标卡尺和量角器对24具成人颈椎干燥标本C3~7椎弓根的高度、宽度、骨性椎管长度、轴线长度、内外侧皮质厚度及轴线夹角进行解剖学测量,并分别计算各节段左右侧椎弓根测量值的均值和标准差,进行统计学分析。结果C3~7椎弓根的椎弓根最窄处截面上下皮质骨高度(PH)和松质骨高度(PSH)分别为4.21mm和7.64mm,宽度分别为3.64mm和5.88mm;轴线长度、骨性椎管长度及侧块部长度分别为15.75mm、32.20mm及8.12mm;最狭窄处内、外侧皮质厚度为0.68mm和1.65mm;椎弓根轴线与矢状线在水平面上的夹角C3:47.12°±3.05°、C4:43.47°±1.49°、C5:40.15±2.58°、C6:38.55°±2.45°、C7:35.16°±2.10°;椎弓根轴线与水平面间夹角C3:8.50°±2.50°、C4:4.83°±1.65°、C5:1.25°±1.45°、C6:-(4.50°±2.50°)、C7:-(8.50°±2.50°)。结论本实验实体测量数据与国内外数据无显著差异,但发现颈椎椎弓根解剖形态个体变异程度较大,术前必须对置钉椎体进行CT、X线片检查,确定适合个体的进钉点、进钉方向、螺钉直径及长度等。颈椎椎弓根螺钉技术仍然是一种相对安全、固定可靠的手术方法。     

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。     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

目的 探讨在下颈椎经颈后正中入路应用经关节螺钉联合侧块螺钉或椎弓根螺钉行内固定治疗的固定效果.方法 2003年2月至2007年10月,对22例患者通过后路应用经关节螺钉联合侧块螺钉或椎弓根螺钉行内固定治疗,男14例,女8例;年龄24～73岁,平均43岁.其中下颈椎创伤性骨折脱位13例,颈椎后纵韧带骨化症4例,颈椎管狭窄伴Ⅱ型齿突骨折1例,颈椎间盘突出伴椎管狭窄4例.结果 共置入经关节螺钉45枚,其中C4,5 2枚,C5,639枚,C6,74枚;共置入侧块螺钉12枚,C3、C4各6枚;共置入椎弓根螺钉41枚,其中C24枚,C32枚,C46枚,C721枚,T18枚.术中所有螺钉均成功置入,未出现椎动脉、神经根和脊髓损伤等置钉相关并发症.22例患者均获随访,随访时间10个月～3年8个月,平均17个月.植骨融合时间3～5个月,平均3.5个月.术后发现1例患者的2枚经关节螺钉松动,部分脱出.经加强颈托制动,术后4个月获得融合.结论 通过后路固定下颈椎时,采用经关节螺钉联合侧块螺钉或椎弓根螺钉固定,均可取得较好的固定效果.     

下颈椎椎弓根螺钉技术的临床应用

目的评估下颈椎椎弓根螺钉技术应用于颈椎不稳定的临床意义,并总结其手术技巧和适应征。方法回顾性分析2004年7月-2006年8月,采用颈。椎弓根螺钉技术治疗的各类颈椎疾患28例146枚钉。创伤患者18例,Frankel分级评价神经损伤情况。包括3例陈旧性下颈椎脱位,均后路一期复位,双侧椎弓根钉钢板固定;非创伤患者10例,予椎管减压,后路钉棒、板系统矫形或重建稳定性。结果术后CT提示椎弓根壁损伤5枚（3．42％）,无1例血管神经损伤表现。随访时间平均9．8（3-24）月。创伤患者Frankel分级无加重,除3例A级患者无恢复外,均有1-3级的脊髓功能恢复,伴发神经根激惹症状减轻或消失;非创伤患者脊髓功能JOA评分由术前6．8分提高至12．5分。结论下颈椎椎弓根螺钉技术是相对安全的操作,可适用于几乎所有需要从后路固定的颈椎病例。重要的是在术前详细分析影像资料,熟悉局部解剖特点,掌握合理的置钉技术,以减少和避免并发症。     

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.     

颈椎斜位X线片在颈椎椎弓根钉固定中应用的研究

目的：探讨通过颈椎斜位X线片观察椎弓根的位置和方向,及其在判断椎弓根钉固定中准确,安全地进行钉的作用。方法：人尸体颈椎30例,其中椎动脉造影8例,椎动脉脊髓同时造影6例,根据术前X线斜位片,结合解剖标记定位,选择是钉点及进行钉方向,将直径3．5mm、长度24mm的不锈钢螺钉固定于C2或C3－C6或C7椎弓根中,共160枚,通过术后斜位X线片中判断螺钉在椎弓根的位置,并与CT扫描结果对照,以肯定X线的判断,结果：螺钉位置方向正确者152枚,X线片与CT扫描片的判断完全相符;X线判断螺钉偏向椎弓根外侧边缘5枚,偏向椎弓根内侧的边缘3枚。CT扫描确位于椎弓根外侧边缘3枚,怀疑进入椎动脉孔的2枚;在椎弓根内侧边缘没有进入椎管的3枚。结论：术前通过X线斜位片基本可以解椎弓根方向,上下径;通过术后X线斜位片可较为准确地判断椎弓根钉在椎弓根内的位置及有无进行推动脉孔、椎管的情况,X线与CT的结果差异可能与CT扫描的角度及其伪影有关,该方法简单易行。     

Complications of transpedicular screw fixation in the cervical spine

Today, posterior stabilization of the cervical spine is most frequently performed by lateral mass screws or spinous process wiring. These techniques do not always provide sufficient stability, and anterior fusion procedures are added secondarily. Recently, transpedicular screw fixation of the cervical spine has been introduced to provide a one-stage stable posterior fixation. The aim of the present prospective study is to examine if cervical pedicle screw fixation can be done by low risk and to identify potential risk factors associated with this technique. All patients stabilized by cervical transpedicular screw fixation between 1999 and 2002 were included. Cervical disorders included multisegmental degenerative instability with cervical myelopathy in 16 patients, segmental instability caused by rheumatoid arthritis in three, trauma in five and instability caused by infection in two patients. In most cases additional decompression of the spinal cord and bone graft placement were performed. Pre-operative and post-operative CT-scans (2-mm cuts) and plain X-rays served to determine changes in alignment and the position of the screws. Clinical outcome was assessed in all cases. Ninety-four cervical pedicle screws were implanted in 26 patients, most frequently at the C3 (26 screws) and C4 levels (19 screws). Radiologically 66 screws (70%) were placed correctly (maximal breach 1 mm) whereas 20 screws (21%) were misplaced with reduction of mechanical strength, slight narrowing of the vertebral artery canal (<25%) or the lateral recess without compression of neural structures. However, these misplacements were asymptomatic in all cases. Another eight screws (9%) had a critical breach. Four of them showed a narrowing of the vertebral artery canal of more then 25%, in all cases without vascular problems. Three screws passed through the intervertebral foramen, causing temporary paresis in one case and a new sensory loss in another. In the latter patient revision surgery was performed. The screw was loosened and had to be corrected. The only statistically significant risk factor was the level of surgery: all critical breaches were seen from C3 to C5. Percutaneous application of the screws reduced the risk for misplacement, although this finding was not statistically significant. There was also a remarkable learning curve. Instrumentation with cervical transpedicular screws results in very stable fixation. However, with the use of new techniques like percutaneous screw application or computerized image guidance there remains a risk for damaging nerve roots or the vertebral artery. This technique should be reserved for highly selected patients with clear indications and to highly experienced spine surgeons.     

颈椎后路双开门脊髓减压椎弓根内固定术治疗颈椎骨折脱位的效果分析

目的探讨颈椎后路双开门脊髓减压椎弓根内固定术治疗颈椎骨折脱位并脊髓损伤患者的治疗效果。方法2000年12月至2008年4月,行颈椎后路双开门脊髓减压椎弓根内固定术治疗38例颈椎骨折脱位并脊髓损伤患者,男28例,女10例;年龄20-80岁,平均43．5岁;颈椎损伤节段：C22例,C33例,C410例,C513例,C68例,C72例。术后行椎弓根螺钉CT检查并观察脊髓神经功能改善状况。结果38例患者C2-7共置入椎弓根螺钉158枚,其中152枚（96．2％）完全置入椎弓根皮质骨内,6枚（3．8％）置入位置不准确,包括进钉位置偏内经椎板进入椎管2枚,偏外挤穿椎弓根外侧皮质4枚。术后随访36例,随访时间1-36个月,平均6．8个月;脊髓神经损伤ASIA分类：A级7例、B级15例、C级13例、D级3例,A级的7例患者中5例感觉下降,恢复至B级;2例感觉完全恢复,上肢肌力有改善,但下肢运动功能无改善,分别恢复至C、D级。其余均有1-3级的功能恢复。无1例继发性血管、神经损伤。结论早期行后路双开门脊髓减压椎弓根内固定术以保持颈椎损伤阶段的稳定性,对颈椎骨折脱位并脊髓损伤患者的功能恢复有显著治疗作用。     

Morphological character of cervical spine for anterior transpedicular screw fixation

Background:

Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic) characters for cervical anterior transpedicular screw fixation.

Materials and Methods:

Left pedicle parameters were measured on computed tomography (CT) images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane), outer pedicle height (OPH) (Distance from upper to lower pedicle surface in the sagittal plane), maximal pedicle axis length (MPAL), distance transverse insertion point (DIP), distance of the insertion point to the upper end plate (DIUP), pedicle sagittal transverse angle (PSTA) and pedicle transverse angle (PTA) at C3 to C7.

Results:

The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5.

Conclusions:

The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.     

椎弓根钉棒系统治疗颈椎不稳定骨折的生物力学研究

目的 研究椎弓根钉棒系统治疗颈椎不稳定骨折的生物力学作用.方法 采用新鲜C3～7段小牛颈椎,制备成椎体屈曲压缩性骨折模型5具(椎管内均有骨块占位),记录椎弓根钉棒系统固定后纵向恒速拉伸过程中各种运动状态下椎管内骨块复位位移变化,描记出纵向拉伸载荷与椎管内骨块复位位移之间的关系曲线.结果 椎管内骨块位移-复位力在起始呈线性变化,但随着位移的增大呈非线性走势;颈椎轴向撑开力为50 N、相同骨块位移值时,前屈状态的骨块回复力比后伸状态大23%(P＜0.05),轴向撑开力为150 N、前屈状态的骨块回复力反而比后伸状态小11 %(P＜0.05);随着轴向撑开力的增大,椎管内骨块回复力增大,即随着载荷的减少,骨块回复的阻力越大.结论 轴向撑开力对椎管内骨折块的复位有重要影响,后纵韧带在骨折块复位过程中起决定性作用.     

经后路颈椎弓根钉系统固定治疗颈椎骨折脱位

[目的]探讨和评价经后路颈椎弓根钉系统治疗颈椎骨折脱位的临床应用价值.[方法]回顾性分析12例颈椎骨折脱们位,并颈脊髓损伤病人行一期经后路椎板切除减压+颈椎弓根钉内固定术的临床疗效.[结果]进针点显露过程中出现静脉从出血1例.其余病例未发生与置钉相火的并发症.所有病例均获随访,随访时间12～24个月,平均18个月.术后脊髓功能均有不同程度恢复.复企X线、CT,颈椎骨折脱位复位良好,无内固定物松动或断钉现象.[结论]经后路颈椎弓根钉系统提供三柱生物力学稳定性,对治疗颈椎骨折脱位有很高临床应用价值.     

Morphometry of the cervical vertebral pedicles as a guide for transpedicular screw fixation

Anatomical measurements of the cervical pedicle in a large series of human cervical vertebrae from 48 individuals were obtained to reduce the incidence and severity of complications caused by transpedicular screw placement. The greatest pedicle length was at C-3 and the greatest pedicle width was at C-6. Pedicle width and lateral mass thickness gradually increased from C-3 to C-6. Pedicle height and interpedicular distance increased from C-3 to C-5, and decreased slightly at C-6. The lateral mass-pedicle length was greatest at C-4. The present study found right-left differences for the pedicle-spinous process distance at C-6 (p < 0.05). Pedicle width and height were smaller than those reported in earlier studies, especially at C-3 and C-4, whereas the increasing pedicle widths at C-5 and C-6 were appropriate for pedicle screw fixation.     

寰椎椎弓根螺钉置钉技巧探讨

[目的]探讨寰椎椎弓根螺钉固定治疗寰枢椎不稳的置钉技巧。[方法]总结2000年10月～2008年9月应用寰椎椎弓根螺钉技术治疗寰枢椎不稳患者66例,置钉132枚。术中在直视下依据手感行寰椎椎弓根螺钉置钉,复位固定。[结果]本组66例132枚螺钉均成功置入,复位固定满意。术中未发现脊髓、神经根、椎动脉等损伤。术后患者症状及神经脊髓功能均有不同程度恢复。96枚螺钉术后行CT检查,其中91枚位置良好(94.89%)。全部病例内固定无松动、断裂,植骨均融合。[结论]术前影像学测量,术中显露寰椎后弓、直视下依据手感置钉、X线确定进钉方向,是安全置钉的技巧。