Placement and complications of cervical pedicle screws in 144 cervical trauma patients using pedicle axis view techniques by fluoroscope

Cervical pedicle screw fixation is an effective procedure for stabilising an unstable motion segment; however, it has generally been considered too risky due to the potential for injury to neurovascular structures, such as the spinal cord, nerve roots or vertebral arteries. Since 1995, we have treated 144 unstable cervical injury patients with pedicle screws using a fluoroscopy-assisted pedicle axis view technique. The purpose of this study was to investigate the efficacy of this technique in accurately placing pedicle screws to treat unstable cervical injuries, and the ensuing clinical outcomes and complications. The accuracy of pedicle screw placement was postoperatively examined by axial computed tomography scans and oblique radiographs. Solid posterior bony fusion without secondary dislodgement was accomplished in 96% of all cases. Of the 620 cervical pedicle screws inserted, 57 (9.2%) demonstrated screw exposure (<50% of the screw outside the pedicle) and 24 (3.9%) demonstrated pedicle perforation (>50% of the screw outside the pedicle). There was one case in which a probe penetrated a vertebral artery without further complication and one case with transient radiculopathy. Pre- and postoperative tracheotomy was required in 20 (13.9%) of the 144 patients. However, the tracheotomies were easily performed, because those patients underwent posterior surgery alone without postoperative external fixation. The placement of cervical pedicle screws using a fluoroscopy-assisted pedicle axis view technique provided good clinical results and a few complications for unstable cervical injuries, but a careful surgical procedure was needed to safely insert the screws and more improvement in imaging and navigation system is expected.     

三维重建技术在上胸椎和颈椎椎弓根螺钉植入的临床应用

目的通过应用三维重建技术辅助椎弓根螺钉的植入,评价其在上胸椎和颈椎置钉中的准确性和安全性。方法 2013年1月至2013年11月,对12例需要行上胸椎、颈椎椎弓根螺钉植入手术的患者术前通过Mimics三维重建图像设计进钉通道并获取相关参数,术中辅助植入上胸椎、颈椎椎弓根螺钉共50枚,术后CT扫描评价螺钉位置,记录有无与螺钉植入的相关并发症。结果通过Mimics三维重建植入的50枚椎弓根螺钉,47枚完全在椎弓根内,3枚穿破椎弓根壁,椎弓根穿破率为6%,植钉准确率为94%,所有穿破椎弓根壁的螺钉的穿出距离均小于2 mm,螺钉位置可接受率为100%。无一例出现螺钉植入有关的神经、血管损伤等并发症。结论 Mimics三维重建技术辅助上胸椎、颈椎椎弓根螺钉植入的置钉准确性高、安全,且明显缩短手术时间。     

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.     

颈椎弓根螺钉置钉并发症原因分析及预防

目的回顾性分析颈椎弓根螺钉置钉术中并发症原因及对策。方法颈椎骨折脱位患者600例采用颈椎弓根螺钉内固定技术治疗,发生置钉并发症36例,男26例,女10例;年龄26~68岁,平均38.9岁。按Frankel分级11例为完全性颈髓损伤;25例为不完全性颈髓损伤。结果在发生置钉并发症36例中共置入椎弓根螺钉204枚,有70枚螺钉方向偏差,其中20枚螺钉初次置入后感觉松动,经校正后二次置入成功;17枚钉道钻孔后出血较多,其中1枚误入横突孔损伤椎动脉,经处理未引起严重后果;术中定位时有33枚螺钉穿出椎弓根,向上进入椎间隙14枚,偏下5枚,偏外8枚,偏内1枚,5枚因方向偏差反复钻孔致椎弓根骨折。32例获得随访,随访时间10~26个月。均获骨性融合。手术后1例患者原有神经症状加重,经过半年康复锻炼症状明显好转。结论颈椎弓根解剖变异较大,应强调颈椎弓根螺钉置入的个体化,术前除应仔细掌握患者颈椎弓根影像学解剖结构特点外,术中还注意技术操作的要点。     

Clinical accuracy of cervical pedicle screw insertion using lateral fluoroscopy: a radiographic analysis of the learning curve

Abstract  

Cervical pedicle screw is thought to be the most stable instrumentation for reconstructive surgery of the cervical spine. However, because of the unresolved and inherent risk of neurovascular injuries due to screw perforation, it remains not widespread nowadays despite the excellent biomechanical property. Fifty-two consecutive cases having undergone spinal reconstruction using cervical pedicle screw were investigated. There were 24 females and 28 males. The mean follow-up period was 53 months. Those patients were stratified into three groups according to the period of screw insertion. A total of 280 screws were inserted. Ninety-two screws in 19 cases, 100 screws in 18 cases and 88 screws in 15 cases were inserted in the earlier, the middle and the later periods, respectively. Clinical results including complications were recorded in all cases. Screw perforations were evaluated in both plain X-ray and CT. Screw perforations occurred in 11 (12.0%), 7 (7.0%) and 1 (1.1%) screws in each period. There were no complications, such as infection, neurological deterioration and neurovascular injury directly related to screw insertion. The learning curve showed a significant improvement especially in the later period. However, the perforation rates in both the earlier and middle periods must not be underestimated. Surgeons with less experience must insert cervical pedicle screws with the assistance of a senior surgeon to avoid lethal complications.     

Translaminar screws of the axis—an alternative technique for rigid screw fixation in upper cervical spine instability

C2 pedicle screws or transarticular atlantoaxial screws are technically demanding and carry an increased risk of vertebral artery injury. In up to 20% of cases, pedicle and transarticular screw placement is not possible due to a high-riding vertebral artery or very small C2 pedicles in addition to other anatomical variations. Translaminar screws have been reported to rigidly capture posterior elements of C2 and therefore appear to be a suitable alternative. We present our first experiences and clinical results with this new method in two neurosurgical spine centers. Twenty-seven adult patients were treated between 2007 and 2010 in two neurosurgical spine departments with C2 translaminar screw fixation for upper cervical spine instability of various origins (e.g., trauma, tumor, dens pseudarthrosis). Eight patients were men and 19 were women. Mean age was 68.9 years. In most cases, translaminar screws were used because of contraindications for pedicle or transarticular screws as a salvage technique. All patients were clinically assessed and had CT scans postoperatively to verify correct screw placement. Follow-up was performed with reexamination on an ambulatory basis. Mean follow-up was 7.6 months for all patients. In 27 patients, 52 translaminar screws were placed. There were no intraoperative complications. Postoperatively, we identified four screw malpositions using a new accuracy grading scale. One screw had to be revised because of violation of the spinal canal >4 mm. None of the patients had additional neurological deficits postoperatively, and all showed stable cervical conditions at follow-up. Two patients died due to causes not associated with the stabilization technique. The fusion rate for patients with C1/C2 fixation is 92.9%. Translaminar screws can be used at least as an additional technique for cases of upper cervical spine instability when pedicle screw placement is contraindicated or not possible. The current data suggest comparable biomechanical stability and fusion rates of translaminar screws to other well-known posterior fixation procedures. In addition, translaminar screw placement is technically less demanding and reduces the risk of vertebral artery injury.     

漏斗技术结合探针技术置入胸椎椎弓根螺钉在脊椎畸形矫形术中的应用

目的 探讨应用漏斗技术结合探针技术置入胸椎椎弓根螺钉在脊椎畸形矫形术中的实用性和安全性。方法 12例脊椎畸形患者接受了后路矫形固定术,在手术矫形过程中,胸椎椎弓根螺钉的置入均采用“漏斗技术结合探针技术”,记录术中和术后并发症;术后常规复查X线片和CT,记录穿出骨皮质螺钉数目及距离。结果 采用“漏斗技术结合探针技术”共置入胸椎椎弓根螺钉129枚,术后复查CT见129枚螺钉中2枚穿透椎弓根内侧壁,3枚螺钉穿破外侧壁;1枚螺钉穿透椎体前壁。Heary分级,其置钉准确性达96.12%。结论 在脊椎畸形矫形术中,应用“漏斗技术结合探针技术”置入胸椎椎弓根螺钉的方法是实用的、安全的。     

Segmental pedicle screw instrumentation in idiopathic thoracolumbar and lumbar scoliosis

The role of posterior correction and fusion in thoracolumbar and lumbar scoliosis as well as pedicle screw instrumentation in scoliosis surgery are matters of debate. Our hypothesis was that in lumbar and thoracolumbar scoliosis, segmental pedicle screw instrumentation is safe and enables a good frontal and sagittal plane correction with a fusion length comparable to anterior instrumentation. In a prospective clinical trial, 12 consecutive patients with idiopathic thoracolumbar or lumbar scolioses of between 40° and 60° Cobb angle underwent segmental pedicle screw instrumentation. Minimum follow-up was 4 years (range 48– 60 months). Fusion length was defined according to the rules for Zielke instrumentation, normally ranging between the end vertebrae of the major curve. Radiometric analysis included coronal and sagittal plane correction. Additionally, the accuracy of pedicle screw placement was measured by use of postoperative computed tomographic scans. Major curve correction averaged 64.6%, with a loss of correction of 3°. The tilt angle was corrected by 67.0%, the compensatory thoracic curve corrected spontaneously according to the flexibility on the preoperative bending films, and led to a satisfactory frontal balance in all cases. Average fusion length was the same as that of the major curve. Pathological thoracolumbar kyphosis was completely corrected in all but one case. One patient required surgical revision with extension of the fusion to the midthoracic spine due to a painful junctional kyphosis. Eighty-five of 104 screws were graded “within the pedicle”, 10 screws had penetrated laterally, 5 screws bilaterally and 4 screws medially. No neurological complications were noted. In conclusion, despite the limited number of patients, this study shows that segmental pedicle screw instrumentation is a safe and effective procedure in the surgical correction of both frontal and sagittal plane deformity in thoracolumbar and lumbar scoliosis of less than 60°, with a short fusion length, comparable to anterior fusion techniques, and minimal loss of correction. Received: 23 September 1999 Revised: 20 January 2000 Accepted: 26 January 2000     

多层螺旋CT三维重建技术辅助脊柱经椎弓根内固定手术

目的研究多层螺旋CT三维重建技术辅助脊柱经椎弓根内固定手术的方法。方法对68例脊柱经椎弓根内固定手术患者行多层螺旋CT薄层扫描后进行容积重建（VR）及多平面重建（MPR）,据此进行辅助诊断、术前计划及个体化测量以指导手术,并在术后评估效果。结果多层螺旋CT三维重建技术辅助下置入椎弓根钉366枚,包括颈椎168枚,胸椎52枚,腰椎146枚。术后复查CT,20枚（5.46%）钉发生超过＂安全区域＂范围的椎弓根穿破,其中颈椎11枚（11/168）发生1～2mm的穿破,1枚（1/168）穿破外侧壁2.2mm,但未出现临床症状,胸椎1枚（1/52）、腰椎7枚（7/146）存在2～4mm的穿破。所有病例术后未发生与置钉相关的脊髓、神经、血管并发症。结论应用多层螺旋CT扫描三维重建辅助脊柱经椎弓根内固定手术,可以量化、个体化确定手术参考指标,提高手术的安全性和准确性。     

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。     

O-arm计算机导航辅助脊柱椎弓根螺钉置入的准确性

[目的]分析O-arm计算机辅助导航技术在脊柱椎弓根螺钉置入的准确性。[方法]回顾性分析2017年1月~2018年9月本院椎弓根螺钉置入患者575例,根据椎弓根螺钉置入方式不同,分为两组。导航组采用O-arm计算机辅助导航技术系统置入椎弓根螺钉233例,传统组采用传统徒手法置入椎弓根螺钉342例。行CT检查,依据Neo分型评估置钉准确性。[结果]导航组共置入1459枚椎弓根螺钉,其中C1~7置入222枚,T1~12置入535枚,L1~5置入652枚,S1置入50枚。每名患者置钉数量1~24枚,平均(6.26±3.77)枚。传统组共置入1724枚椎弓根螺钉,其中C1~7置入269枚,T1~12置入601枚,L1~5置入785枚,S1置入87枚。每名患者置钉数量1~20枚,平均(5.67±4.11)枚。导航组全部病例顺利完成手术,术中无血管、神经损伤等并发症,置钉安全率为100%,传统组有4例发生血管、神经损伤等并发症。所有患者术后进行12~24个月随访,随访过程均未发生不良事件。依据CT影像Neo分级标准,导航0型及1型椎弓根螺钉的成功置入率达98.01%,而传统组0型及1型椎弓根螺钉的成功置入率91.85%;两组间置入螺钉准确性的差异具有统计学意义(P<0.05)。[结论]与传统C臂X线机等徒手置钉方式相比,O-arm计算机辅助导航技术可提高脊柱椎弓根螺钉置入准确性,同时降低神经、血管等并发症的发生。     

颈椎椎弓根螺钉徒手植入技术的临床研究

目的 评价颈椎椎弓根螺钉徒手植入技术（无须术中影像技术引导）的安全性和可靠性。方法应用Axis内固定系统（美国枢法模公司）对36例颈椎疾病患者进行颈后路经椎弓根内固定术,共植入螺钉144枚,方法如下：①术中清晰地显露颈椎侧块和突间关节,用直径3,0mm高速球形磨钻去除侧块外上象限处骨皮质,然后用2．0mm的自制手锥沿椎弓根事先确定的方向轻轻钻入,若遇阻力则需略改变方向,使其自然置入,深约2～2,5cm。确定无误后,则安置Axis钛板和置入长度合适的椎弓根螺钉。②安装完毕后,即用C型臂X线机作双斜位透视,无误后关闭切口。结果从G～G,共植入根弓根螺钉144枚,其中10枚（6．8％）钉初次置入后感觉松动,经校正后二次置入成功,11枚（3．5％）钉道钻孔后出血较多,但及时处理后出血停止并无不良结果。术后X线斜位片及CT片显示,16枚（11．1％）螺钉穿破椎弓根,其中10枚螺钉（6．9％）穿破椎弓根外侧皮质,4枚（2．8％）穿破椎弓根上侧皮质,2枚（1．3％）穿破椎弓根下侧皮质。随访未发现与螺钉置入穿破椎弓根皮质有关的神经血管损伤问题。结论本研究提示,在事先充分的对每个患者颈椎椎弓根X线及CT解剖结构了解的情况下,徒手置入椎弓根螺钉行颈椎后路内固定安全可行。     

A free‐hand technique for pedicle screw placement in the lower cervical spine

Objective: To describe a free‐hand method for pedicle screw placement in the lower cervical spine with no intraoperative imaging monitors, and to evaluate the safety of this technique. Methods: A study of the free‐hand technique of cervical pedicle screw placement was conducted by postoperative radiological review and follow‐up. Thirty‐six patients who had had cervical reconstruction with posterior plate utilizing pedicle screw fixation, and been followed for a minimum of 2 years, were studied. The position of the pedicle screw was evaluated by postoperative oblique radiographs and axial computed tomograms. Clinical outcomes were measured by Odem's criteria. Results: A total of 144 screws of diameter 3.5 or 4.0 mm were inserted into the cervical pedicles in 36 patients. Postoperative images showed that 16 (11.1%) of the screws had penetrated the pedicle walls. Among them, 10 (6.9%) screws had penetrated the lateral, 4 (2.8%) the superior and 2 (1.3%) the inferior walls. However, there were no neurological or vascular complications related to the malpositioned screws during a minimum of 2 years follow‐up. In addition, Odem's scores were applied postoperatively in all patients except one with complete neurological deficit. Conclusion: Based on 144 screw placements, cervical pedicle screw insertion utilizing a free‐hand technique without intraoperative imaging guidance seems to be safe and reliable. However, solid knowledge of the anatomy of the cervical pedicle and adjacent neurovascular bundles, and careful preoperative review of cervical images, are imperative for successful screw placement in the cervical spine.     

脊柱虚拟手术系统辅助下颈椎椎弓根置钉的临床评估

目的:评价脊柱虚拟手术系统(spinal virtual surgery system,SVSS)辅助下行颈椎椎弓根置钉的准确性。方法:对收治的有术后多层螺旋CT(MSCT)复查资料的27例行椎弓根螺钉固定的下颈椎疾患病例,分为SVSS 3D技术辅助手术组(A组,10例)和MSCT 3D技术辅助手术组(B组,17例)。两组病例术前均行螺旋CT扫描,A组原始数据导出CT工作站,格式转换后导入SVSS系统行三维重建;B组原始数据直接在CT工作站行三维重建。两系统都选择VR和MPR重建,开展术前个体化评估以指导手术。术后螺旋CT复查评估置钉准确性,螺钉穿破评价参照Richter分级标准。结果:A组术后10例共50枚螺钉中44枚(88%)完全位于椎弓根内;6枚(12%)穿破椎弓根,其中1级穿破5枚(10%),2级穿破1枚(2%)。B组术后17例共76枚螺钉中67枚(88.16%)完全位于椎弓根内;9枚(11.84%)穿破,其中1级穿破6枚(7.89%),2级穿破3枚(3.95%)。两组间穿破率比较差异无显著性(P>0.05)。结论:SVSS可应用于实施术前个体化评估、个体化治疗方案制定及术后疗效评估和康复锻炼指导等。     

O形臂实时导航在颈椎椎弓根螺钉固定术中的应用

目的:探讨在O形臂导航下提高颈椎椎弓根螺钉置钉准确性的技术要点。方法:对2015年12月至2020年1月接受O形臂导航下颈椎椎弓根钉内固定术治疗的21例患者进行回顾性分析,其中男15例,女6例,年龄29～76(45.3±11.5)岁。术后CT扫描以Gertzbein&Robbins分级评估颈椎弓根螺钉置钉的准确性。结果:21例患者共置入132枚椎弓根螺钉,其中116枚置于C₃-C₆节段,16枚置于环枢椎。术后CT扫描根据Gertzbein&Robbins分级,11.36%(15/132)打破椎弓根,其中73.33%(11/15)为B级,26.67%(4/15)为C级,无D-E级破壁。所有患者术后随访无内固定所致相关并发症。结论:在合理选择适应证的前提下,O形臂导航下能够提高颈椎椎弓根螺钉置钉准确性和可靠性,使得手术医师更有信心进行复杂困难的颈椎内固定操作。但是考虑到颈椎弓根周围重要而复杂的邻近解剖结构,以及可能导致的灾难性后果,不仅应该熟练掌握导航技术要点,积累足够操作经验,同时警惕影像漂移,不应完全依赖导航。     

Percutaneous instrumentation of the cervical and cervico-thoracic spine using pedicle screws: preliminary clinical results and analysis of accuracy

The pedicle screw instrumentation represents the most rigid construct of the cervical and cervicothoracic spine and in spite of the risks to neurovascular structures clinical relevant complications do not occur frequently. The steep angles of the cervical pedicles result in a wide surgical exposure with extensive muscular trauma. The objective of this study was the evaluation of the accuracy of cervical pedicle screw insertion through a minimally invasive technique to reduce access-related muscular trauma. Therefore, percutaneous transpedicular instrumentation of the cervical and cervicothoracic spine was performed in 15 patients using fluoroscopy. All instrumentations from C2 to Th4 were inserted bilaterally through 2 to 3-cm skin and fascia incisions even in multilevel procedures and the rods were placed by blunt insertion through the incision. Thin-cut CT scan was used postoperatively to analyze pedicle violations. 76.4% of 72 screws were placed accurately. Most pedicle perforations were seen laterally towards the vertebral artery. Critical breaches >2 mm or narrowing of the transversal foramen occurred in 12.5% of screws; however, no revision surgery for screw displacement was needed in the absence of clinical symptoms. No conversion from percutaneous to open surgery was necessary. It was concluded that percutaneous transpedicular instrumentation of the cervical spine is a surgically demanding technique and should be reserved for experienced spine surgeons. The indications are limited to instrumentation-only procedures or in combination with anterior treatment, but with the potential to minimize access-related morbidity.     

数字化“定点-定向”双导航模板辅助椎弓根螺钉置钉治疗寰枢椎不稳

目的评价数字化"定点-定向"双导航模板辅助椎弓根螺钉置钉治疗寰枢椎不稳的临床效果。方法回顾性分析2013年9月—2016年12月收治的24例采用数字化"定点-定向"双导航模板辅助行颈椎后路椎弓根螺钉置钉的寰枢椎不稳患者的临床资料。术前CT扫描获取数据经Mimics 10.0软件三维重建后进行寰枢椎后路椎弓根螺钉置钉理想钉道的计算机辅助规划,并根据寰枢椎后方骨性结构表面数据设计个性化"定点-定向"双导航模板。在3D打印机上制作"定点-定向"双导航模板,高温消毒后应用于临床手术辅助置钉。术后根据颈椎X线和CT检查结果评价椎弓根螺钉的位置,并观察植骨融合情况及颈椎稳定性。采用颈部和/或枕骨下疼痛视觉模拟量表(VAS)评分评估患者的临床疗效。结果应用数字化双导航模板为24例患者置入椎弓根螺钉,22例行寰枢椎后路椎弓根螺钉固定,2例行寰枢椎后路椎弓根螺钉并椎板螺钉固定。共置入寰椎椎弓根螺钉48枚,枢椎椎弓根螺钉46枚,枢椎椎板螺钉2枚。术后CT检查示所有螺钉均未穿破钉道骨皮质。所有患者随访6个月,大部分患者颈部疼痛明显缓解,VAS评分由术前(7.78±1.12)分降至术后(2.48±0.55)分,差异有统计学意义(P0.05)。术前肌力下降者术后均不同程度恢复。所有患者均未发生神经、血管损伤等置钉相关并发症。结论数字化"定点-定向"双导航模板不仅能够提高手术置钉的准确性和安全性,还能针对不同类型的寰枢椎不稳提供更合理的置钉方式。     

Posterior occipitocervical reconstruction using cervical pedicle screws and plate-rod systems.

STUDY DESIGN: This retrospective study was conducted to analyze the clinical results in 26 patients with lesions at the craniocervical junction that had been treated by occipitocervical reconstruction using pedicle screws in the cervical spine and occipitocervical rod systems. OBJECTIVES: To evaluate the effectiveness of pedicle screw fixation in occipitocervical reconstructive surgery and to introduce surgical techniques. SUMMARY OF BACKGROUND DATA: Many methods of occipitocervical reconstruction have been reported, but there have been no reports of occipitocervical reconstruction using pedicle screws and occipitocervical rod systems for reduction and fixation. METHODS: Twenty-six patients with lesions at the craniocervical junction underwent reconstructive surgery using pedicle screws in the cervical spine and occipitocervical rod systems. The occipitocervical lesions were atlantoaxial subluxation associated with basilar invagination, which was caused by rheumatoid arthritis in 19 patients and other disorders in 7. The lowest cervical vertebra of fusion in 16 patients was C2, and the remaining 10 patients underwent fusion downward from C3 to C7. Flexion deformity of the occipitoatlantoaxial complex was corrected by application of extensional force, and upward migration of the odontoid process was reduced by application of combined force of extension and distraction between the occiput and the cervical pedicle screws. RESULTS: Solid fusion was achieved in all patients except two with metastatic vertebral tumors who did not receive bone graft for fusion. Correction of malalignment at the craniocervical junction was adequate, and postoperative magnetic resonance imaging showed improvement of anterior compression of the medulla oblongata. There were no neurovascular complications of cervical pedicle screws. CONCLUSIONS: Occipitocervical reconstruction by the combination of cervical pedicle screws and occipitocervical rod systems provided the high fusion rate and sufficient correction of malalignment in the occipitoatlantoaxial region. Results of this study showed the effectiveness of cervical pedicle screw as a fixation anchor for occipitocervical reconstruction.     

Accuracy of pedicle screw placement using patient-specific template guide system

BackgroundDespite repeated efforts for accurate cervical pedicle screw insertion, malpositioning of the inserted screw is commonly noted. To avoid neurovascular complications during cervical pedicle screw insertion, we have developed a new patient-specific screw guide system. This study aimed to evaluate the accuracy of cervical PS placement using the new patient-specific screw guide system.MethodsThis study is a retrospective clinical evaluation of prospectively enrolled patients. Seventeen consecutively enrolled patients who underwent posterior cervical fusion using the guide system were included. Firstly, three-dimensional planning of pedicle screw placement was done using simulation software. A screw guide for each vertebra was constructed preoperatively. A total of 77 screws were inserted with the guides. Postoperative computed tomography was used to evaluate pedicle perforation, and screw deviations, between the planned and actual screw positions, were measured.ResultsA total of 76 screws (98.7%) were completely inside the pedicle (C3-7), without neurovascular injuries. The mean screw deviations from the planned trajectory at the narrowest point of the pedicle and at the entry point in the axial and sagittal planes were 0.56 ± 0.43 mm and 0.43 ± 0.35 mm and 0.43 ± 0.30 mm and 0.63 ± 0.50 mm, respectively. There were no significant differences in any parameter at different spinal levels. Angular deviations in the sagittal and axial planes were 2.94 ± 2.04° and 2.53 ± 1.85°, respectively. Sagittal angular deviations tended to increase in the cranial vertebra (C3 and C4) compared to the middle cervical spine.ConclusionsWe demonstrated that our patient-specific screw guide is vital for guiding precise screw insertion in the cervical pedicle. This technique may be an effective solution for achieving precise screw insertion and reducing the incidence of complications.     

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。