Iso-C 3D导航系统下椎弓根钉内固定治疗颈椎骨折脱位

[目的]探讨在Iso-C 3D导航系统下行椎弓根螺钉内固定治疗颈椎骨折、脱位的临床意义。[方法]在Iso-C 3D导航系统下,应用椎弓根螺钉内固定治疗颈椎骨折、脱位共31例,观察临床疗效及置钉的准确性。[结果]本组31例中,共置入136枚椎弓根螺钉。术后X线片显示,颈椎骨折脱位复位均满意,颈椎生理曲度恢复良好。术后CT显示,136枚椎弓根螺钉中,有6枚螺钉穿破椎弓根,穿透皮质率4.4%,但均未造成脊髓、神经、血管压迫等。经随访,X线显示所有病例融合区均骨性愈合,无1例出现断钉及内置物松动现象。合并脊髓损伤的患者,术后神经功能均有不同程度的恢复。[结论]椎弓根螺钉技术稳定性良好,具有优越的生物力学性能,为颈椎骨折脱位行后路内固定提供了一种安全有效的方法,在Iso-C 3D导航下行颈椎椎弓根螺钉内固定手术,能显著提高椎弓根螺钉置入的准确性和安全性。     

颈椎椎弓根螺钉内固定系统在颈椎的应用

目的 :介绍颈椎弓根螺钉的应用方法和适应证 ,为临床提供应用经验。方法 :回顾分析 17例应用颈椎椎弓根内固定系统治疗的患者手术前后的临床表现及X线。结果 :17例患者均获随访 ,随访平均 12个月 ,固定节段均达骨性愈合 ,神经功能不同程度恢复 ,临床效果满意。结论 :颈椎弓根内固定能达到固定坚固及有效的椎管减压 ,有助于神经功能的恢复 ,是一种良好颈椎内固定方法。     

椎弓根螺钉内固定治疗枢椎椎弓根骨折合并脊髓损伤

目的 评价椎弓根螺钉内固定治疗枢椎弓根骨折(Hangman骨折)的临床应用价值。方法 回顾性分析我科自1999年来收治的急性枢椎椎弓根骨折15例患者，其中Ⅰ型4例，Ⅱ型11例，均合并不同程度神经系统症状，行颅骨牵引复位后用AO纯钛皮质骨螺钉经峡部固定枢椎椎弓根骨折。结果 经12～60个月随访，术后神经功能恢复按Frankel分级，有6例D级和5例C级恢复至E级，2例V级恢复至D级，1例B级恢复至C级，1例B级恢复至D级，半年后复查X线骨折均愈合，复位良好，无椎动脉损伤及其它术中、术后并发症。结论 椎弓根螺钉内崮定治疗早期枢椎椎弓根骨折，复位固定满意，有利于脊髓功能的恢复，且较少影响上颈椎功能。     

下颈椎椎弓根螺钉内固定技术在临床中的应用

目的 :探讨下颈椎椎弓根螺钉内固定技术的临床应用。方法 :对2011年9月至2013年7月行下颈椎椎弓根螺钉内固定的32例患者进行回顾性分析,男20例,女12例;年龄21~78岁,平均56.4岁。其中10例为创伤性颈髓损伤,9例为颈椎管内肿瘤,7例颈椎后纵韧带骨化症,6例多节段颈椎病。所有患者术前行X线、CT、MRI及椎动脉MRA等影像学检查,术后及随访时行X线片及CT平扫明确螺钉的位置情况。根据Lee等4级分类法评价置钉的准确性,创伤性患者行ASIA分级评价脊髓功能变化,非创伤性患者采用JOA评分评价神经功能改善情况。结果:32例患者成功置入144枚下颈椎椎弓根螺钉,术后CT显示,0级132枚,1级5枚,2级5枚,3级2枚。有12枚螺钉穿破椎弓根,其中8枚螺钉穿破椎弓根外侧皮质,2枚螺钉穿破椎弓根下侧皮质,穿破椎弓根内侧、上侧皮质螺钉各1枚。术后随访12~33个月,平均(21.0±1.5)个月,6例完全性颈髓损伤患者术后神经功能虽无恢复,但截瘫平面下降1~3个脊髓节段。4例不完全性颈髓损伤患者术后按ASIA损伤分级提高1~2级。22例非创伤性患者术后6个月JOA评分平均(15.9±0.6)分,较术前(11.5±0.8)分明显提高(P<0.01)。所有患者未发现钉棒系统松动、断裂情况。结论:下颈椎椎弓根螺钉固定能提供优秀的三维稳定性。合理选择适应证,术前充分准备以及根据椎弓根形态个体化置钉可以最大限度的降低手术风险及手术并发症,值得临床应用推广。     

C2椎弓根钉结合 C3侧块螺钉内固定治疗不稳定 Hangman 骨折简

目的探讨颈椎后路C2椎弓根钉结合C3侧块螺钉内固定治疗不稳定Hangman骨折的临床效果。方法对不稳定Hangman骨折28例入院后均颅骨牵引,行C2椎弓根钉结合C3,侧块螺钉内固定术。结果经24—42个月随访．术后神经功能恢复按Frankel分级,8例D级恢复至E级,20例E级未变化;6个月后骨折均愈合,复位良好,无椎动脉损伤等并发症。结论C2椎弓根钉结合C3侧块螺钉内固定术治疗不稳定Hangman骨折可获得满意疗效。     

多层螺旋CT三维重建技术在胸腰椎骨折经椎弓根螺钉内固定术中的应用价值

目的:探讨多层螺旋CT(MSCT)三维重建技术在胸腰椎骨折患者经椎弓根螺钉内固定术中的应用价值。方法:2007年1月~2008年12月,78例胸腰椎骨折患者在我院行椎弓根螺钉内固定术,其中38例使用传统置钉法(Weinstein法或AO法)进行椎弓根螺钉置入(A组),40例采用MSCT三维重建设计钉道的置钉方法进行螺钉置入(B组),术后两组均复查胸腰椎正、侧位X线片和CT了解置入螺钉位置情况,应用Lonstein等的方法评判置钉准确率。结果:78例患者共置入椎弓根螺钉436枚,A组38例共置入212枚,12例32枚螺钉穿破椎弓根皮质,其中穿破椎弓根内外皮质21枚,穿破椎弓根上下皮质11枚,置钉准确率84.91%;B组40例共置入224枚,5例6枚螺钉穿破椎弓根皮质,其中穿破椎弓根内外皮质4枚,穿破椎弓根上下皮质2枚,置钉准确率97.33%。两组置钉准确率有统计学差异(P<0.05)。结论:胸腰椎骨折患者行椎弓根螺钉内固定时应用MSCT三维重建设计钉道的置钉方法较传统置钉方法成功率高。     

钉道设计在颈椎椎弓根固定中的应用

[目的]探讨钉道设计在颈椎椎弓根固定中的应用.[方法]2006～2009年16例患者在本院接受下颈椎椎弓根螺钉内固定术,术前采用颈椎螺旋CT三维重建,测量该组患者颈椎椎弓根的长度、宽度、高度、向内侧倾斜、向头侧倾斜、向尾侧倾斜角度的数据,以此为指导行术中置入椎弓根螺钉.术后半月内采用与术前程序一致的螺旋CT三维重建及钉道扫描,观察椎弓根螺钉与椎弓根各壁的关系.[结果]颈椎弓根变异较大.本组共置钉66枚,57枚螺钉完全位于椎弓根内,9枚螺钉穿破椎弓根外侧皮质壁,其中5枚穿破距离为1 mm,4枚螺钉穿破距离为2～3 mm,无椎动脉和脊髓损伤发生,置钉准确率为93%.[结论]钉道设计对术中个体化置入颈椎弓根螺钉有重要意义.     

寰枢椎椎弓根螺钉置钉技术的临床应用

目的：探讨寰枢椎椎弓根螺钉置钉技术在上颈椎损伤临床应用的效果。方法选择性应用寰枢椎椎弓根螺钉固定技术治疗 Jefferson 骨折5例,齿状突骨折11例,Hangman 骨折9例。结果术中无椎动脉、脊髓及神经根损伤发生。1例暴露时损伤静脉丛,予以压迫即能止血;1例寰枢椎骨折不完全复位。患者均获随访,时间1～2年。患者临床症状明显改善,术后1年行 X 线及 CT 检查,显示所有骨折均骨性愈合,螺钉位置良好,无松动、断钉。结论寰枢椎椎弓根螺钉内固定技术具有固定可靠及骨折愈合率高等特点,为上颈椎损伤提供了坚固的稳定性。     

颈椎椎弓根钉内固定治疗颈椎骨折脱位21例体会

目的 探讨应用颈椎椎弓根螺钉固定治疗颈椎骨折,评价其疗效及安全性.方法 采用经椎弓根内固定技术治疗颈椎骨折脱位患者21例,术前通过影像学对椎弓根形态进行评估,术中结合C臂机定位实施椎弓根钉的植入.结果 所有病例均获得8～26个月随访,平均12个月,术后X线及CT检查示螺钉位置正常,骨性愈合良好;18例脊髓和神经根不全损伤患者术后神经功能明显改善,按ASIA损伤分级平均提高1～3级.2例脊髓完全损伤患者术后功能无明显改善.结论 重视术前颈椎椎弓根形态学评估,术中结合C臂机定位,植钉个体化,可以获得满意的临床疗效和安全性.     

新型单椎单侧椎弓根导向模板辅助下颈椎椎弓根个体化置钉

目的探讨新型单椎单侧椎弓根导向模板辅助下颈椎椎弓根个体化置钉的准确性。方法对需要行颈椎后路椎弓根内固定治疗的22例下颈椎患者术前行CT扫描,根据CT扫描资料,利用逆向工程原理及快速成型技术,采用Mimics 16.0和Imageware 12.0软件,制作颈椎三维模型,并设计出个体化的新型单椎单侧椎弓根导向模板,辅助颈椎椎弓根置钉。术后复查颈椎CT评价椎弓根螺钉的位置,按照Lee et al的评定方法将螺钉在椎弓根内的位置分为4级:0级,螺钉完全位于椎弓根内;1级,穿破椎弓根的部分螺钉直径的25%;2级,螺钉直径的25%~50%穿破椎弓根;3级,穿破椎弓根的部分螺钉直径的50%。0级和1级认为置钉满意,2级和3级认为螺钉误置。结果 22例均获得随访,时间6~36个月。22例患者共置入椎弓根螺钉113枚,改为侧块螺钉固定3枚。术后复查CT提示椎弓根螺钉位置107枚为0级,4枚为1级,2枚为2级。仅2例发生误置,置钉准确率达98.2%。其中1级和2级共6枚椎弓根螺钉均穿破椎弓根外侧壁,无椎弓根内侧壁及上、下壁穿破情况。对螺钉穿破外侧壁的患者行椎动脉MRA检查,未见椎动脉损伤。患者均未出现螺钉误置导致的脊髓、神经损伤并发症。结论新型单椎单侧椎弓根导向模板辅助下颈椎椎弓根个体化置钉准确性高,相关并发症少,为下颈椎椎弓根的置入提供了一种新的方法。     

Placement of pedicle screws in the human cadaveric cervical spine: comparative accuracy of three techniques

STUDY DESIGN: This investigation was conducted in two parts. In the first part, a morphometric analysis of critical cervical pedicle dimensions were measured to create guidelines for cervical pedicle screw fixation based on posterior cervical topography. In the second part of the study, a human cadaver model was used to assess the accuracy and safety of transpedicular screw placement in the subaxial spine using three different surgical techniques: 1) using surface landmarks established in the first part of the study, 2) using supplemental visual and tactile cues provided by performing laminoforaminotomies, and 3) using a computer-assisted surgical guidance system. OBJECTIVE: To assess the accuracy of transpedicular screw placement in the cervical spine using three surgical techniques. SUMMARY OF BACKGROUND DATA: A three-column fixation device implanted to secure an unstable cervical spine can be a valuable tool with a biomechanical advantage in the spine surgeon's armamentarium. Despite this advantage, concerns over surgical neurovascular complications have surfaced. Cadaver-based morphometric measurements used to guide the surgeon in the placement of a pedicle screw show significant variability, raising legitimate concerns as to whether transpedicular fixation can be applied safely. METHODS: Precise measurements of 14 human cadaveric cervical spines were made by two independent examiners of pedicle dimensions, angulation, and offset relative to the lateral mass boundaries. On the basis of this analysis, guidelines for pedicle screw placement relative to posterior cervical topography were derived. In the second part of the study, 12 human cadaveric cervical spines were instrumented with 3.5-mm screws placed in the pedicles C3-C7 according to one of three techniques. Cortical integrity and neurovascular injury were then assessed by obtaining postoperative computed tomography scans (1-mm cuts) of each specimen. Cortical breaches were classified into critical or noncritical breaches. RESULTS: Linear measurements of pedicle dimensions had a wide range of values with only fair interobservercorrelation. Angular measurements showed similarangulation in the transverse plane (40 degrees ) at each level. With respect to the sagittal plane, both C3 and C4 pedicles were oriented superiorly relative to the axis of the lateral mass, whereas the C6 and C7 pedicles were oriented inferiorly. The dorsal entry point of the pedicle on the lateral mass defined by transverse and sagittal offset had similar mean values with wide ranges, although there often was excellent correlation between observers. There were no significant interlevel, right/left, or male/female differences noted with respect to offset. Using one of three techniques, 120 pedicles were instrumented. In group 1 (morphometric data): 12.5% of the screws were placed entirely within the pedicle; 21.9% had a noncritical breach; and 65. 5% had a critical breach. In group 2 (laminoforaminotomy), 45% of the screws were within the pedicle; 15.4% had a noncritical breach; and 39.6% had a critical breach. In group 3 (computer-assisted surgical guidance system), 76% of the screws were entirely within the pedicle; 13.4% had a noncritical breach; and 10.6% had a critical breach. Regardless of the technique used, the vertebral artery was the structure most likely to be injured. CONCLUSIONS: On the basis of the morphometric data, guidelines for cervical spine pedicle screw placement at each subaxial level were derived. Although a statistical analysis of cadaveric morphometric data obtained from the cervical spine could provide guidelines for transpedicular screw placement based on topographic landmarks, sufficient variation exists to preclude safe instrumentation without additional anatomic data. Insufficient correlation between different surgeons' assessments of surface landmarks attests to the inadequacy of screw insertion techniques in the cervical spine based on such specific topographic guide     

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.     

上颈椎损伤合并不连续下颈椎损伤的一期手术治疗

目的 探讨上颈椎损伤合并不连续的下颈椎损伤的临床特点及手术治疗策略.方法 2004年5月至2007年8月,对上颈椎损伤合并不连续的下颈椎损伤9例患者进行一期手术治疗.术前神经功能按Frankel评级:A级2例,C级3例,E级4例.其中上颈椎损伤均采用后路手术,经椎弓根寰枢固定融合8例,枕颈固定1例;下颈椎损伤采用后路手术6例,其中以不连续经椎弓根短节段钉棒固定融合4例,2例采用联合上颈椎经椎弓根连续固定;余3例同期行前路减压钛板固定.结果 所有患者获得6～48个月(平均13.7个月)随访.术中无一例椎动脉损伤.术后无气管切开或拔管延迟情况,无严重肺部感染、呼吸衰竭、应激性溃疡等并发症发生.患者复位及融合满意,1例2枚下颈椎椎弓根断钉.神经功能:除2例Frankel A级的患并无恢复外,余均为E级.结论 上颈椎损伤合并不连续下颈椎损伤导致颈椎极度不稳定,伴有的神经损伤常源于下颈段.一期手术治疗,包括上颈椎后路经椎弓根固定及下颈椎后路经椎弓根或前路减压固定,相对安全且可获得满意疗效.     

管道疏通法行颈椎弓根螺钉置入的研究

目的：通过解剖学测量及临床应用探讨“管道疏通法”（dredging pipe method,DPM)对提高颈椎弓根螺钉置入的成功率、安全性及可操作性方面的应用价值。方法：（1）颈椎骨测量：成人C3－C7干燥骨42套，共210块椎骨，在实体及CT片上，测量椎骨的相关参数；92）临床应用：颈椎失稳症患者32例，术前X线、CT测量，参照标本及患者影像测量数据和管道疏通器自动寻迹的原理，个体化设计各椎节的置钉方案。在直视下显露椎弓根管口及其管腔，确定置钉方向和位置，扩孔攻丝置钉。术后观察对比相应指标，评价置钉的位置、方向。结果：91）与DPM相关的国人颈椎实体测量数据与CT测量数据比较无显著性差异（P＞0．05）；6．67％（28／42）椎弓根的宽度小于4mm;(2)32例患者共置入颈椎弓根钉146枚，术后CT复查96枚钉，其中5枚螺钉穿破椎弓根骨皮质，成功率94．8％。未出现神经血管损伤病例。结论：（1）术前影像学测量结果可人为个体化设计手术方案的重要依据，采用DPM置钉技术实施经颈椎弓根钉内固定手术，具有直视下操作、置钉准备率高、可操作性强等特点；（2）解剖学测量表明，极少部分人（6．67％）的C3－C7的椎弓根宽度不适宜做椎弓根钉内固定。     

Accuracy of pedicle screw insertion in the cervical spine for internal fixation using frameless stereotactic guidance

OBJECT: Although transpedicular fixation is a biomechanically superior technique, it is not routinely used in the cervical spine. The risk of neurovascular injury in this region is considered high because the diameter of cervical pedicles is very small and their angle of insertion into the vertebral body varies. This study was conducted to analyze the clinical accuracy of stereotactically guided transpedicular screw insertion into the cervical spine. METHODS: Twenty-seven patients underwent posterior stabilization of the cervical spine for degenerative instability resulting from myelopathy, fracture/dislocation, tumor, rheumatoid arthritis, and pyogenic spondylitis. Fixation included 1-6 motion segments (mean 2.2 segments). Transpedicular screws (3.5-mm diameter) were placed using 1 of 2 computer-assisted guidance systems and lateral fluoroscopic control. The intraoperative mean deviation of frameless stereotaxy was < 1.9 mm for all procedures. RESULTS: No neurovascular complications resulted from screw insertion. Postoperative computed tomography (CT) scans revealed satisfactory positioning in 104 (90%) of 116 cervical pedicles and in all 12 thoracic pedicles. A noncritical lateral or inferior cortical breach was seen with 7 screws (6%). Critical malplacement (4%) was always lateral: 5 screws encroached into the vertebral artery foramen by 40-60% of its diameter; Doppler sonographic controls revealed no vascular compromise. Screw malplacement was mostly due to a small pedicle diameter that required a steep trajectory angle, which could not be achieved because of anatomical limitation in the exposure of the surgical field. CONCLUSIONS: Despite the use of frameless stereotaxy, there remains some risk of critical transpedicular screw malpositioning in the subaxial cervical spine. Results may be improved by the use of intraoperative CT scanning and navigated percutaneous screw insertion, which allow optimization of the transpedicular trajectory.     

Computer-assisted screw insertion for cervical disorders in rheumatoid arthritis

To reconstruct highly destructed unstable rheumatoid arthritis (RA) cervical lesions, the authors have been using C1/2 transarticular and cervical pedicle screw fixations. Pedicle screw fixation and C1/2 transarticular screw fixation are biomechanically superior to other fixation techniques for RA patients. However, due to severe spinal deformity and small anatomical size of the vertebra, including the lateral mass and pedicle, in the most RA cervical lesions, these screw fixation procedures are technically demanding and pose the potential risk of neurovascular injuries. The purpose of this study was to evaluate the accuracy and safety of cervical pedicle screw insertion to the deformed, fragile, and small RA spine lesions using computer-assisted image-guidance systems. A frameless, stereotactic image-guidance system that is CT-based, and optoelectronic was used for correct screw placement. A total of 21 patients (16 females, 5 males) with cervical disorders due to RA were surgically treated using the image-guidance system. Postoperative computerized tomography and plane X-ray was used to determine the accuracy of the screw placement. Neural and vascular complications associated with screw insertion and postoperative neural recovery were evaluated. Postoperative radiological evaluations revealed that only 1 (2.1%; C4) of 48 screws inserted into the cervical pedicle had perforated the vertebral artery canal more than 25% (critical breach). However, no neurovascular complications were observed. According to Ranawat's classification, 9 patients remained the same, and 12 patients showed improvement. Instrumentation failure, loss of reduction, or nonunion was not observed at the final follow-up (average 49.5 months; range 24-96 months). In this study, the authors demonstrated that image-guidance systems could be applied safely to the cervical lesions caused by RA. Image-guidance systems are useful tools in preoperative planning and in transarticular or transpedicular screw placement in the cervical spine of RA patients.     

Subaxial cervical pedicle screw insertion with newly defined entry point and trajectory: accuracy evaluation in cadavers

Successful placement of cervical pedicle screws requires accurate identification of both entry point and trajectory. However, literature has not provided consistent recommendations regarding the direction of pedicle screw insertion and entry point location. The objective of this study was to define a guideline regarding the optimal entry point and trajectory in placing subaxial cervical pedicle screws and to evaluate the screw accuracy in cadaver cervical spines. The guideline for entry point and trajectory for each vertebra was established based on the recently published morphometric data. Six fresh frozen cervical spines (C3–C7) were used. There were two men and four women. After posterior exposure, the entry point was determined and the cortical bone of the entry point was removed using a 2-mm burr. Pilot holes were created with a cervical probe based on the guideline using fluoroscopy. After tapping, 3.5-mm screws with appropriate length were inserted. After screw insertion, every vertebra was dissected and inspected for pedicle breach. The pedicle width, height, pedicle transverse angulation and actual screw insertion angle were measured. A total of 60 pedicle screws were inserted. No statistical difference in pedicle width and height was found between the left and right sides for each level. The overall accuracy of pedicle screws was 83.3%. The remaining 13.3% screws had noncritical breach, and 3.3% had critical breach. The critical breach was not caused by the guideline. There was no statistical difference between the pedicle transverse angulation and the actual screw trajectory created using the guideline. There was statistical difference in pedicle width between the breach and non-breach screws. In conclusion, high success rate of subaxial cervical pedicle screw placement can be achieved using the recently proposed operative guideline and oblique views of fluoroscopy. However, careful preoperative planning and good surgical skills are still required to ensure screw placement accuracy and to reduce the risk of neural and vascular injury.     

寰枢椎脱位后路螺钉固定方法的临床选择

目的 探讨寰枢椎脱位后路钉棒固定术中寰椎螺钉和枢椎螺钉固定方法 的临床选择.方法 对2002 年11 月至2011 年12 月广州军区广州总医院收治的228 例可复性和23 例难复性寰枢椎脱位患者,术前进行置钉可行性和复位可能性评估,针对性地选择寰椎和枢椎的后路螺钉固定方法,进行寰枢椎后路钉棒固定治疗.结果 251 例患者均行钉棒固定并获得满意复位.寰椎螺钉固定采用椎弓根螺钉403 枚、部分经椎弓根螺钉77 枚、侧块螺钉22 枚;枢椎螺钉固定采用椎弓根螺钉437 枚、椎板螺钉56 枚、侧块螺钉9 枚.术中未发生椎动脉、脊髓损伤.237 例患者获得随访,随访时间4～38 个月,平均随访时间13 个月.230 例患者获骨性融合;6例为纤维愈合,动力位片（均随访2 年以上）未见复发脱位;另1 例为假关节未融合并双侧枢椎椎弓根螺钉松动,行后路翻修手术治愈.结论 根据寰枢椎脱位的复位难易程度和个体解剖特点灵活选择寰椎和枢椎不同的后路螺钉固定方法,扩大了寰枢椎后路钉棒固定技术的适用范围,提高了手术安全性和成功率.     

Cervical anterior transpedicular screw fixation. Part I: Study on morphological feasibility,indications, and technical prerequisites

Multilevel cervical spine procedures can challenge the stability of current anterior cervical screw-and-plate systems, particularly in cases of severe three-column subaxial cervical spine injuries and multilevel plated reconstructions in osteoporotic bone. Supplemental posterior instrumentation is therefore recommended to increase primary construct rigidity and diminish early failure rates. The increasing number of successfully performed posterior cervical pedicle screw fixations have enabled more stable fixations, however most cervical pathologies are located anteriorly and preferably addressed by an anterior approach. To combine the advantages of the anterior approach with the superior biomechanical characteristics of cervical pedicle screw fixation, the authors developed a new concept of a cervical anterior transpedicular screw-and-plate system. An in vivo anatomical study was performed to explore the feasibility of anterior transpedicular screw fixation (ATPS) in the cervical spine. The morphological study was conducted based on 29 cervical spine CT scans from healthy patients and measurements were performed on the pedicle sizes, angulations, vertebral body depth, height and width at C2 to T1. Significant morphologic parameters for the new technique are discussed. These parameters include the sagittal and transverse intersection points of the pedicle axis with the anterior vertebral body wall, as well as the distances between sagittal intersection points from C2 to T1. On the basis of these results, standard spine models were reconstructed and used for the conceptual development of a preclinical release prototype of an anterior transpedicular screw-and-plate system. The morphological feasibility of the new technique is demonstrated, and its indications, biomechanical considerations, as well as surgical prerequisites are thoroughly discussed. In the future, the technique of cervical anterior transpedicular screw fixation might diminish the number of failures in the reconstruction of multilevel and three-column cervical spine instabilities, and avoid the need for supplemental posterior instrumentation.