前路经寰枢关节螺钉内固定术治疗寰枢关节不稳定的解剖学及临床研究

目的 为前路经寰枢关节螺钉内固定术提供临床解剖学依据.方法 在100对中国成人干燥寰、枢椎配对标本上,对与临床前路经寰枢关节螺钉内固定术相关的数据进行解剖学测量.并对11例创伤性寰枢椎不稳定患者施行了前路经寰枢关节螺钉内固定术,在齿状突与寰椎前结节后方置入颗粒状松质骨.结果 前路经寰枢关节螺钉内固定术冠状面上螺钉植入最小外偏角(5.5±2.0)度,最大外偏角(23.6±2.1)度,矢状面上螺钉植入最小后倾角(14.9±2.6)度,最大后倾角(25.6 ±2.5)度,内侧钉道距离(16.58±1.49)mm,外侧钉道距离(26.44±1.75)mln.11例患者中,1例颈脊髓完全损伤患者,术后1个月死于肺部感染.其余10例病例获得随访,时间7个月～3年,平均17个月,无椎动脉及脊髓损伤,所有病例获得骨性融合.结论 前路经寰枢关节螺钉内固定术,操作简便,损伤脊髓或椎动脉的风险较小,为寰枢椎不稳定患者提供了一种新的内固定治疗方法.     

三种后路寰枢椎融合术的离体生物力学研究

目的 通过离体生物力学研究方法,比较3种后路寰枢椎融合技术的力学稳定性.方法 将8具新鲜尸体的颈椎标本(C1～4)置于1.5 Nm载荷下,测量C1、2关节的三维运动范围(ROM).每具标本依双侧经寰枢关节间隙螺钉结合Gallie内固定术、双侧经寰枢关节间隙螺钉结合寰椎椎板钩内固定术、双侧寰椎侧块螺钉结合枢椎椎弓根螺钉内固定术的顺序实施固定,每次固定后测量三维运动范围.结果 包含经寰枢关节间隙螺钉的内固定组在旋转和侧屈方向上具有最小的ROM角度,其中新型的双侧经寰枢关节间隙螺钉结合寰椎椎板钩内固定组在前屈后伸运动方向上也具有最小ROM角度.寰椎侧块螺钉结合枢椎椎弓根螺钉内固定组在旋转方向上ROM角度显著大于单独经寰枢关节螺钉内固定组,但在侧屈和前屈后伸方向上ROM角度近似于经寰枢关节间隙螺钉,差异无统计学意义.结论 双侧经寰枢关节间隙螺钉结合寰椎椎板钩内固定术具有最强的生物力学稳定性;双侧寰椎侧块螺钉结合枢椎椎弓根螺钉内固定术与双侧经寰枢关节间隙螺钉结合寰椎椎板钩内固定技术比较,具有相似的力学稳定性.     

颈椎椎弓根螺钉内固定术治疗寰枢椎不稳

目的总结颈椎椎弓根螺钉技术治疗寰枢椎不稳的效果,探讨寰枢椎不稳的固定方法。方法采用颈后路椎弓根螺钉内固定植骨融合治疗寰枢椎不稳8例。术前均行颅骨牵引。结果平均随访12个月。所有患者症状消失,植骨块全部融合,无内固定装置松动。结论椎弓根螺钉技术稳定性良好,具有三维固定的优点,为颈后路内固定提供了一种安全有效的方法。     

前路经寰枢关节螺钉内固定三维稳定性的实验研究

目的：评价前路经寰枢关节螺钉内固定术治疗寰枢椎不稳定的三维稳定性。方法：8具新鲜颈椎标本，对每一标本分别测定正常状态、齿状突Ⅱ型骨折、前路经寰枢关节螺钉内固定术、后路Maged螺钉内固定术4种状态下的三维运动范围。结果：前路经寰枢关节螺钉内固定术与后路Magerl螺钉内固定术均能明显减少寰枢关节各方向运动范围，经统计学检验两种固定方法无显著性差异（P〉0．05）。结论：前路经寰枢关节螺钉内固定术的三维稳定性与后路Maged螺钉内固定术相当，为寰枢椎不稳定患者的治疗提供了另一种选择。     

后路经关节螺钉内固定治疗创伤性寰枢椎不稳定46例

目的：探讨后路经关节螺钉内固定治疗创伤性寰枢椎不稳定疗效。方法采用以枢椎下关节突下缘中点为进钉点的后路改良节螺钉内固定治疗寰枢椎不稳定46例。结果术后随访5～48个月,平均21个月。寰枢椎获解剖复位44例,未解剖复位2例,内固定位置均良好。寰枢椎于术后2～3个月均获得骨性融合,临床症状缓解,无并发症发生。结论后路改良经关节螺钉内固定术,操作简便,疗效可靠,可作为治疗寰枢椎不稳定的有效术式。     

前路经寰枢外侧关节螺钉内固定术的生物力学评价

目的：评价不同方法前路经寰枢外侧关节螺钉内固定的稳定性和刚度。方法：通过体外生物力学实验，对15例新鲜尸体标本的正常、齿状突切除、三种不同有路经寰枢外侧关节螺钉内固定术、后路Brooks法寰枢关节内固定术等状态进行三维角度运动范围和关节刚度进行测试。结果：前路经寰枢外侧关节螺钉内固定术明显减少寰枢关节的各向角度运动范围；三种不同方法之间寰枢关节的各向角度运动范围和刚度无明显差异；前路经寰枢外侧关节螺钉内固定术较后路Brooks法内固定术，寰枢关节的旋转和侧屈运动范围减少更明显，寰枢关节的由前向后剪切和旋转刚度更高。结论：前路经寰枢外侧关节螺钉内固定术的稳定性和刚度达到了临床治疗的要求，术后对外固定强度的依赖较低，三种不同方法的生物力学结果相近，为简化操作和设计提供了新思路。     

前路三钉内固定治疗寰椎-齿状突Ⅱ型骨折

背景：齿状突加寰枢椎前路经关节螺钉内固定是近来治疗寰椎-齿状突Ⅱ型骨折的一种新方法,临床报道较少。 目的：探讨颈前路三钉,即齿状突螺钉加寰枢椎前路经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折的方法及疗效。 方法：2008年2月至2011年10月于C型臂X线机透视下行颈前路齿状突螺钉加寰枢椎经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折5例。 结果：5例骨折患者共植入5枚齿状突螺钉,9枚经寰枢关节螺钉,1例因左侧经寰枢关节螺钉进钉点处骨折而行右侧单侧固定。全部获得随访,随访时间为10~30个月,平均18个月,螺钉位置满意,齿状突骨折均获骨性愈合,寰枢关节稳定,无一例发生螺钉松动、断钉,无一例发生脊髓、椎动脉损伤等并发症。 结论：颈前路齿状突螺钉加寰枢椎经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折,对齿状突直接固定同时即刻稳定寰枢椎,为寰椎-齿状突Ⅱ型骨折患者提供了一种新的治疗方法。     

前路经枢椎体至寰椎侧块螺钉内固定三维稳定性的实验研究

目的：评价前路经枢椎体至寰椎侧块螺钉内固定三维稳定性。方法：16具成人标本（C0–C3）,对每一标本分别测定完整状态（第1组）、齿状突Ⅱ型骨折（第2组）、后路经关节螺钉内固定术（Magerl技术）（第3组）、前路经枢椎体至寰椎侧块螺钉内固定（第4组）4种状态下的三维运动范围,并进行统计学分析。结果：1组与其他3组、2组与其他3组比较差异有统计学意义（P〈0.001）。前路经枢椎体至寰椎侧块螺钉内固定与后路Magerl螺钉内固定均能显著减少寰枢关节各方向运动范围,两种固定方法差异无统计学意义（P〉0.05）。结论：前路经枢椎体至寰椎侧块螺钉内固定的三维稳定性与后路Magerl螺钉内固定术相当,为寰枢椎不稳定及脱位患者的治疗提供了一种可靠的手术选择。     

寰枢椎后路经关节改良螺钉内固定治疗寰枢椎不稳定

目的探讨寰枢椎不稳定患者行寰枢椎后路经关节改良螺钉内固定手术方法与疗效。方法对16例寰枢椎不稳定患者,采用枢椎下关节突下缘中点为进钉点的经关节螺钉内固定及自体颗粒样松质骨植骨治疗。结果随访5～48个月,16例患者寰枢椎稳定性均获得恢复与骨融合,无并发症。结论寰枢椎后方经关节螺钉内固定,可提供牢固的固定,恢复寰枢椎稳定,并发症发生率低。     

经寰枢椎椎弓根螺钉技术治疗寰枢椎不稳症

目的 探讨经寰枢椎椎弓根螺钉固定植骨融合治疗寰枢椎不稳症的置钉方法及疗效.方法 应用经寰枢椎椎弓根螺钉内固定术治疗寰枢椎不稳症25例.结果 25例100枚螺钉均成功置入,术后4～6个月植骨融合,未发现钉棒断裂及松动.结论 经寰枢椎椎弓根螺钉固定植骨融合术可直视下置钉、短节段固定,是治疗寰枢椎不稳症一种值得推荐的治疗方法...     

前路松解复位后路内固定治疗难复性寰枢关节脱位

目的：探讨难复性寰枢关节脱位的手术治疗方法。方法：对3例难复性寰椎前脱位的病例经口咽入路切断颈长肌、头长肌、前纵韧带和寰枢侧块关节囊，施行松解复位术，同期行后方固定植骨融合术。后方固定方法包括：经寰枢侧块关节螺钉固定、寰枢侧块钉板固定和借助于枢椎椎弓根螺钉的枕颈固定。结果：3例均获得了解剖复位和植骨融合。结论：经口咽入路的寰枢关节松解复位术可使难复性脱位的寰枢关节获得充分复位，松解复位术是一种安全、有效的治疗方法。     

Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability

Purpose

Even though transarticular screw (TAS) fixation has been commonly used for posterior C1–C2 arthrodesis in both traumatic and non-traumatic lesions, anterior TAS fixation C1–2 is a less invasive technique as compared with posterior TAS which produces significant soft tissue injury, and there were few reports on percutaneous anterior TAS fixation and microendoscopic bone graft for atlantoaxial instability. The goals of our study were to describe and evaluate a new technique for anterior TAS fixation of the atlantoaxial joints for traumatic atlantoaxial instability by analyzing radiographic and clinical outcomes.

Methods

This was a retrospective study of seven consecutive patients with C1–C2 instability due to upper cervical injury treated by a minimally invasive procedure from May 2007 to August 2009. Bilateral anterior TAS were inserted by the percutaneous approach under Iso-C3D fluoroscopic control. The atlantoaxial joint space was prepared for morselized autogenous bone graft under microendoscopy. The data for analysis included time after the injuries, operating time, intraoperative blood loss, X-ray exposure time, clinical results, and complications. Radiographic evaluation included the assessment of atlantoaxial fusion rate and placement of TAS. Bone fusion of the atlantoaxial joints was assessed by flexion extension lateral radiographs and 1-mm thin-slice computed tomography images as radiographic results. Clinical assessment was done by analyzing the recovery state of clinical presentation from the preoperative period to the last follow-up and by evaluating complications.

Results

A total of 14 screws were placed correctly. The atlantoaxial solid fusion without screw failure was confirmed by CT scan in seven cases after a mean follow-up of 27.5 months (range 18–45 months). All patients with associated clinical presentation made a recovery without neurologic sequelae. Postoperative dysphagia occurred and disappeared in two cases within 5 days after surgery. There were no other complications during the follow-up period.

Conclusions

Percutaneous anterior TAS fixation and microendoscopic bone graft could be an option for achieving C1–C2 stabilization with several potential advantages such as less tissue trauma and better accuracy. Bilateral TAS fixation and morselized autograft affords effective fixation and solid fusion by a minimally invasive approach.     

经口咽前路寰枢椎复位钢板内固定的生物力学研究

目的 研究经口咽前路寰枢椎复位钢板(TARP)的三维运动范围和螺钉拔出力的生物力学. 方法 12例C0～C3新鲜标本,6例用于三维运动测试,分七组:①完整标本(对照)组,②损伤组(去除C1前弓、C2齿突,破坏关节囊和横韧带等),③TARP组,④后路Brooks钢丝组,⑤Magerl经关节螺钉组,⑥Magerl+Brooks组,⑦前路经枢椎体寰椎侧块螺钉组,分别测量其三维运动范围(ROM).另6例(双侧,n=12)分解为单个椎体后用于螺钉拔出力测试,分三组:①寰椎组,②枢椎组,③C,(对照)组,测定最大拔出力、钉道长度和屈服长度.结果 TARP组和Magerl+Brooks组在各个方向上差异均无统计学意义(P>0.05),前者的ROM值略大于后者,二者抗屈伸、侧屈和旋转均强于其他三种内固定方法(P<0.05).寰椎与枢椎、寰椎与C3的最大拔出力之间差异均有统计学意义(P<0.05),枢椎和c3椎体最大拔出力之间差异无统计学意义(P>0.05)[最大拔出力分别为C1=(491.58 4±67.92)N,C2=(396.73±60.99)N,C3=(385.53±96.77)N].寰椎与枢椎、寰椎与C3椎体的钉道长度之间差异均有统计学意义(均为P<0.05),枢椎和C3椎体钉道长度之间差异无统计学意义(P>0.05).三组的屈服长度之间差异.无统计学意义(P>0.05).C1～C3的螺钉最大拔出力与钉道长度和屈服长度均呈显著正相关(P<0.05,r分别为0.810和0.652),但与钉道长度的相关性更高(P<0.05). 结论 TARP与目前临床应用的后路Magerl+Brooks术式等效,较其他三种固定方式(前路经枢椎体寰椎侧块螺钉、后路Magerl经关节螺钉和后路Brooks钢丝固定)具有更坚强的固定作用.TARP的寰椎和枢椎固定螺钉固定牢靠,钉道长度即进钉深度是影响螺钉抗拔出力的主要因素,屈服长度是影响螺钉拔出力的次要因素.     

Percutaneous atlantoaxial anterior transarticular screw fixation combined with mini-open posterior C1/2 wire fusion for patients with a high-riding vertebral artery

Context/objective: To describe the technique and clinical results of percutaneous atlantoaxial anterior transarticular fixation combined with limited exposure posterior C1/2 arthrodesis in patients with a high-riding vertebral artery.

Design setting: Zhejiang Spine Center, China.

Participants: Five patients with a high-riding vertebral artery and an upper cervical fracture.

Interventions: Percutaneous atlantoaxial anterior transarticular screw fixation combined with limited exposure posterior C1/2 wire fusion.

Outcome measures: Computed tomography scans were used to assess the high-riding vertebral artery and feasibility of anterior transarticular screw fixation preoperatively. A Philadelphia collar was used to immobilize the neck postoperatively. Anteroposterior (open-mouth) and lateral views were obtained at pre/postoperation and at the follow-up.

Results: The operation was performed successfully on all of the patients, and no intraoperative operation-related complications such as nerve injury, vertebral artery, and soft tissue complications occurred. The mean follow-up period was 33.8 months (range: 24 to 58 months). No screw breakage, loosening, pullout, or cutout was observed. Bone union was achieved in all patients at the last follow-up.

Conclusions: Our small case series results suggested that percutaneous anterior transarticular screw fixation combined with mini-open posterior C1/2 wire fusion is a technically minimally invasive, safe, feasible, and useful method to treat patients with a high-riding vertebral artery.     

Hypoglossal nerve palsy after posterior screw placement on the C-1 lateral mass. Case report

Atlantoaxial fixation in which C1-2 screw-rod fixation is performed is a relatively new method. Because reports about this technique are rather scant, little is known about its associated complications. In this report the authors introduce hypoglossal nerve palsy as a complication of this novel posterior atlantoaxial stabilization method. A 67-year-old man underwent a C1-2 screw-rod fixation for persistent neck pain resulting from a Type 2 odontoid fracture that involved disruption of the transverse atlantal ligament. Posterior instrumentation in which a C-1 lateral mass screw and C-2 pedicle screw were placed was performed. Postoperatively, the patient suffered dysphagia with deviation of the tongue to the left side. At the 4-month follow-up examination, bone fusion was noted on plain x-ray studies of the cervical spine. His hypoglossal nerve palsy resolved completely 2 months postoperatively. To the authors' knowledge, this is the first report in the literature of hypoglossal nerve palsy following C1-2 screw-rod fixation. The hypoglossal nerve is one of the structures that can be damaged during C-1 lateral mass screw placement.     

一种新型后路寰枢椎固定系统的设计及有限元分析

目的:基于影像学参数设计一种新型后路寰枢椎固定系统,运用有限元方法评价该系统固定的生物力学稳定性。方法:运用医学影像存档与通信系统测量工具对后弓发育正常且结构完整的成人寰椎CT进行解剖学参数测量,依据寰椎影像学测量参数设计出一种符合寰椎解剖结构的新型后路寰枢椎固定系统。对1例健康志愿者上颈椎进行薄层CT扫描,对其CT图片数字图像处理,进行网格划分、设置材料属性及载荷与边界条件,建立正常上颈椎有限元模型(正常模型),并与已发表文献对比验证其有效性;在正常模型基础上通过修改材料属性及去除横韧带构建寰枢椎失稳有限元模型(失稳模型),加载新型后路寰枢椎内固定系统至失稳模型上建立新型后路寰枢椎固定系统固定有限元模型(新型模型);运用Abaqus 2019对新型模型施加扭矩为1.5N·m,对该模型C0-C3节段屈伸、侧屈、旋转活动度进行计算分析,并与寰枢椎椎弓根螺钉固定有限元模型(椎弓根螺钉模型)对比。结果:设计出的新型后路寰枢椎固定系统符合寰椎的解剖结构,此系统由新型寰椎后弓钢板、连接棒及枢椎椎弓根螺钉组成。与以往文献对比,建立的正常模型验证有效。新型模型与正常模型相比减少了屈伸95.3%、侧屈92.6%、旋转99.0%的活动度,在各状态明显减少置入节段(C1-2)的活动度。有限元分析得出新型模型在屈伸、侧屈、旋转状态下C1-2节段活动度分别为1.10°、0.49°、0.59°,与椎弓根螺钉模型活动度相近;新型模型C2/3椎间盘最大应力在前屈、后伸、左侧屈、右侧屈、左旋转、右旋转状态下分别为3.71MPa、5.84MPa、3.09MPa、3.43MPa、2.65MPa、3.59MPa,与正常模型最大应力一致;新型后路寰枢椎固定系统固定的应力主要集中于枢椎椎弓根螺钉根部及连接棒。结论:新型后路寰枢椎固定系统固定具有良好的生物力学稳定性,可作为寰枢椎失稳内固定的补充方式。     

Evaluation of biomechanical properties of anterior atlantoaxial transarticular locking plate system using three-dimensional finite element analysis

Purpose

To evaluate a new anterior atlantoaxial transarticular locking plate system using finite element analysis.

Methods

Thin-section spiral computed tomography was performed from occiput to C₂ region. A finite element model of an unstable atlantoaxial joint, treated with an anterior atlantoaxial transarticular locking plate system, was compared with the simple anterior atlantoaxial transarticular screw system. Flexion, extension, lateral bending, and axial rotation were imposed on the model. Displacement of the atlantoaxial transarticular screw and stress at the screw–bone interface were observed for the two internal fixation systems.

Results

Screw displacement was less using the anterior atlantoaxial transarticular locking plate system compared to simple anterior atlantoaxial transarticular screw fixation under various conditions, and stability increased especially during flexion and extension.

Conclusions

The anterior atlantoaxial transarticular locking plate system not only provided stronger fixation, but also decreased screw-bearing stress and screw–bone interface stress compared to simple anterior atlantoaxial transarticular screw fixation.     

Anatomical relationship of the internal carotid artery to C-1: clinical implications for screw fixation of the atlas

OBJECT: Various C1-2 instrumentation techniques have been developed to treat atlantoaxial instability. Screw fixation of C1-2 poses a risk of injury to the vertebral artery and internal carotid artery (ICA). Injury to the ICA caused by C-1 screws is extremely rare, but has been described. To characterize this risk, the authors studied the anatomical relationship of the ICA to the lateral mass of C-1. METHODS: The authors studied 100 patients who had undergone computed tomography scanning and magnetic resonance imaging of the neck to assess the position of the ICA in association with the C-1 lateral mass. Each ICA was classified into 1 of the following 4 zones: Zone 1 (medial to lateral mass), Zone 2 (medial half of lateral mass), Zone 3 (lateral half of lateral mass), and Zone 4 (lateral to lateral mass). For patients with an ICA ventral to the lateral mass, the shortest distance between the ICA and lateral mass was measured to determine the margin of error with an overpenetrated bicortical screw. RESULTS: Of the 100 patients, 58% had a left ICA in Zones 2 and 3 with a mean distance from the anterior cortex of 3.5+/-1.5 mm (+/- standard deviation), and 74% had a right ICA in Zones 2 and 3 with a mean distance from the anterior cortex of 3.9+/-1.6 mm. Both ICAs anterior to the lateral mass were noted in 47% of patients, and 84% had >or= 1 ICA anterior to the lateral mass. When the ICA was anterior to the lateral mass, it was more commonly in the lateral half (left ICA in 91% and right ICA in 92%). The left ICA was in Zone 1 in 1% and Zone 4 in 41%. The right ICA was in Zone 1 in 1% and Zone 4 in 25%. CONCLUSIONS: A high percentage of patients demonstrate an ICA directly ventral to the C-1 lateral mass, which poses a risk of ICA injury caused by an overpenetrated bicortical screw.     

Modified Gallie technique versus transarticular screw fixation in C1-C2 fusion

The effectiveness of a modified Gallie technique versus Magerl and Seeman transarticular screw fixation was compared in the management of 27 patients with symptomatic atlantoaxial instability. Twelve patients were treated using a modified Gallie technique and postoperative halo vest immobilization. Atlantoaxial arthrodesis occurred in seven (58%) patients, stable fibrous union occurred in one patient, and pseudarthrosis with recurrent instability developed in four (33%) patients. Average followup was 6.9 years. All 15 patients treated using Magerl and Seeman transarticular screw fixation and postoperative soft collar immobilization had atlantoaxial arthrodesis develop. Average duration of followup was 4 years. One patient sustained vertebral artery injury during preparation for screw placement. Magerl and Seeman transarticular screw fixation provides stability and more reliably produces atlantoaxial arthrodesis than the Gallie technique provides in patients with atlantoaxial instability without the need for rigid postoperative bracing. Potential for vertebral artery exists despite apparent accurate screw placement. To ensure that safe transarticular screw placement is possible, preoperative fine cut axial computed tomography with reconstructions is required to assess vertebral artery position and C2 isthmus anatomy. A proportion of patients have anatomy unsuitable for screw placement. Traditional wiring techniques are indicated in these patients.