Atlantoaxial transarticular screw fixation and posterior fusion using polyester cable: a 10-year experience

Purpose

To retrospective review the clinical outcomes of the modified operative technique using a polyester suture material (Ethibond* Excel) for atlantoaxial transarticular screw fixation and posterior fusion.

Methods

The retrospective reviews were conducted from 2002 to 2012. The patient’s medical record reviews included demographic data, cause of atlantoaxial instability, orthopedic and surgical history, clinical presentation, radiographic finding including plain radiography, complications, operative detail, and outcome of treatment. Fusion of C1–C2 was defined as either graft consolidation or absence of C1–C2 movement on lateral flexion–extension radiograph.

Results

Twenty-three patients demonstrated clinical and radiographic evidence of atlantoaxial instability (13 men and 10 women, with a mean age of 42 years). Majority of atlantoaxial instability was caused by trauma. Most common clinical symptom was neck pain with or without cervical myelopathy. Bilateral screws were placed in 18 of the 23 patients. Five patients underwent placement of unilateral screws. The 13 patients were inserted by screws with diameter 4.0 mm. The means screw length was 40.33 mm. The means of operative time and estimated blood loss were 3.6 h and 234 ml, respectively. The mean of follow-up duration was 18 months. All 41 screws were positioned satisfactorily in C1 lateral mass. All 23 patients achieved fusion (100 % fusion rate). After a period of follow-up, 9 of the 10 neurological deficit patients had completely recovered.

Conclusions

We concluded that the atlantoaxial transarticular screw fixation and posterior fusion using polyester cable can be used for C1–2 fusion with a high fusion rate and less complications in various cases.     

Atlantoaxial instability treated with transarticular screw fixation

We treated 11 patients with atlantoaxial instability using transarticular posterior screw fixation and lateral bone grafting. A posterior bone graft was added in eight patients. The results showed good reduction and a stable fixation. After 6 months ten patients had regained almost 70% of rotation and did not notice any significant limitation.     

前路经寰枢关节螺钉内固定植骨融合治疗寰枢关节不稳

目的探讨前路经寰枢关节螺钉内固定植骨融合治疗寰枢关节不稳的手术方法及临床疗效。方法对23例寰枢关节不稳患者行前路寰枢关节螺钉内固定植骨融合治疗。结果所有患者术后无脊髓、椎动脉和食道损伤等并发症发生。23例获4～45个月随访(平均18.4个月),随访期间所有患者寰枢关节稳定性良好,21例寰枢关节螺钉位置满意,17例获得植骨融合。结论前路经寰枢关节螺钉内固定植骨融合术是治疗寰枢关节不稳的有效方法,能使寰枢关节即刻稳定性获得良好恢复,同时达到植骨融合的目的。     

Atlantoaxial stabilization: clinical comparison of posterior cervical wiring technique with transarticular screw fixation

Symptomatic atlantoaxial instability requires atlantoaxial stabilization. In this study the authors compared clinical, radiographic, and cervical outcome questionnaire results in 67 such patients who underwent 71 separate procedures. Thirty-eight patients had traditional posterior C1-C2 cervical wiring and halo-vest immobilization (group 1), whereas 33 were alternatively managed with transarticular screw fixation without rigid external immobilization (group 2). Mean follow-up in group 1 was 53.2 months and mean follow-up in group 2 was 41.0 months. Radiographic evaluation demonstrated seven pseudoarthroses and four fibrous unions in group 1, with six patients subsequently undergoing reoperation. There were no pseudoarthroses and two fibrous unions in the transarticular screw group (p = 0.015). In those that fused, >2-mm displacement occurred in six of the group 1 patients (p = 0.027). There was a trend toward fewer complications in group 2 patients (p = 0.085) with four complications, as compared with 12 complications in group 1, including a 21% incidence of halo-vest-related complications. These results demonstrate the significant benefits of transarticular screw fixation over posterior cervical wiring techniques in the management of atlantoaxial instability.     

经寰枢关节螺钉内固定治疗寰枢椎损伤

目的:探讨经寰枢关节螺钉内固定治疗寰枢椎损伤的有效性和安全性。方法:对15例寰枢椎损伤患者进行经寰枢关节螺钉内固定手术治疗。其中包括C2齿状突骨折10例;创伤性寰枢椎前方不稳定5例。结果:术后随访时疼痛明显减轻,术前VAS评分5.5~9.0分,平均7.6分;术后VAS评分1.5~4.5分,平均3.4分,有显著性差异(P<0.001)。随访6~42个月,影像学融合率为86.67%。结论:经寰枢关节螺钉内固定是一种安全有效的治疗方法,但术前应进行严格的影像学形态观察,以排除手术禁忌证。     

Atlanto-axial fusion with transarticular screw fixation

We reviewed 161 patients, from four centres in Switzerland, who had undergone posterior fusion of the upper cervical spine with transarticular screw fixation of the atlanto-axial joints. They were followed up for a mean 24.6 months. The vertebral artery and the medulla escaped injury and only 5.9% of the complications were directly related to the screws. The rate of pseudarthrosis was 0.6%.     

Atlantoaxial fusion using anterior transarticular screw fixation of C1–C2: technical innovation and biomechanical study

This study is an attempt to describe a new technique for anterior transarticular screw fixation of the atlantoaxial joints, and to compare the stability of this construct to posterior transarticular screw fixation with and without laminar cerclage wiring. Nine human cadaveric specimens were included in this study. The C1–C2 motion segment was instrumented using either anterior transarticular screws (group 1), posterior transarticular screws alone (group 2), or posterior screws with interlaminar cerclage wires (group 3). Using an unconstrained mechanical testing machine, the specimens were tested in rotation, lateral bending, and flexion-extension using nondestructive loads of ±2 N m. The specimens were also tested in translation using nondestructive loads of ±100 N. All values for the three groups with regards to anterior-posterior displacement, rotation, and lateral bending were similar as determined using a Kruskal–Wallis rank sum test with a significance level of p<0.05. The only significant difference was registered in flexion-extension where the cerclage wire added some strength to the construct. Anterior transarticular screw fixation of the atlantoaxial spine has several advantages over posterior fixation techniques, and is as stable as posterior transarticular fixation in all clinically significant planes of motion. The addition of posterior interlaminar cerclage wiring further improves resistance to flexion-extension forces. Anterior transarticular screw fixation of the atlantoaxial joint is a useful technique for achieving C1–C2 stabilization.     

下颈椎后路经关节螺钉内固定的解剖学研究

目的明确下颈椎后路经关节螺钉固定的技术参数，为临床应用提供参考。方法取20具（男14具、女6具）尸体颈椎标本，仔细解剖颈部的后侧和侧前方，以清晰地暴露颈椎侧块，保护好脊神经前、后支（C2-7）及其与周围结构的关系。确定安全的进、出钉点，从C2.3-C5.6直视下置人经关节螺钉。通过CT重建，测量经关节固定螺钉的角度、长度、螺钉尖与椎动脉的距离，并确定经关节螺钉矢状面的安全进钉角度（sagittal safety angle，SSA）。结果经关节固定螺钉方向在矢状面呈尾倾，冠状面呈外倾，各固定节段间略有不同，但差异无统计学意义（P〉0．05）。下颈椎后路经关节螺钉固定的理想角度为在矢状面尾倾平均37.3^o±5．0^o，在冠状面外倾平均16．6^o±4．6^o。经关节螺钉钉道长度平均为（18．7±1.4）mm，在C2.3，水平螺钉钉道长度与C3.4C4.5C5.6比较差异有统计学意义（P〈0．05）。后路经关节螺钉矢状面安全进钉角度为41．9^o±5．6^o，螺钉钉尖与椎动脉的距离平均为（5．8＋1．5）mm，各固定节段间略有不同，但差异无统计学意义（P〉0．05）。结论下颈椎后路经关节螺钉置钉时要求一定的准确性，可以作为颈椎侧块螺钉和椎弓根螺钉固定的一种补充内固定方法。     

后路经寰枕关节螺钉内固定的解剖学研究

目的明确后路经寰枕关节螺钉固定的技术参数,为临床治疗提供参考。方法20具包含完整寰枕关节的干燥骨标本,于直视下经寰枕关节置入克氏针固定后拍摄X线片,在X线片上测量经寰枕关节螺钉固定的螺钉角度和长度。对30名健康成年人的寰枕关节行三维CT重建,测量后路经寰枕关节螺钉内固定螺钉角度的可调范围。对12具新鲜枕颈部标本行后路枕寰枢经关节螺钉内固定,然后拍摄X线片并行三维CT重建,以明确螺钉位置。结果经寰枕关节固定螺钉方向在矢状面呈上倾,冠状面呈内倾,左右两侧略有不同,但差异无统计学意义(P>0.05)。后路经寰枕关节螺钉固定的理想角度在矢状面的上倾角为53.3°±3.4°,在冠状面的内倾角为20.0°±2.6°,钉道长度为(29.28±2.46)mm。三维CT重建显示上倾角的可调范围为24.9°～74.6°,内倾角的可调范围为0.7°～40.5°。在新鲜标本上按照上述角度进行后路枕寰枢经关节螺钉内固定,影像学检查结果显示,螺钉钉道均经过寰枕关节,无进入神经管者。结论后路经寰枕关节螺钉固定时对准确性要求较高,结合后路C1,2经关节螺钉固定可视为能满足当前临床需要的一种较好的枕颈融合方法。     

后路改良经关节螺钉内固定术治疗寰枢椎不稳定

[目的]探讨寰枢椎不稳定的手术方法与疗效.[方法]采用以枢椎下关节突下缘中点为进钉点的后路改良经关节螺钉内固定加自体颗粒样松质骨植骨术治疗寰枢椎不稳定20例,其中,新鲜外伤4例,陈旧性外伤14例,先天性畸形1例,椎管内肿瘤1例.术后定期观察椎体复位、内固定、骨融合、临床表现变化及并发症发生情况.[结果]双侧螺钉内固定20例,加后路钢丝固定3例.寰枢椎获解剖复位19例,大部分矫正1例,内固定位置均良好.随访16～64个月,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.     

寰枢关节后路内固定稳定性的生物力学比较研究

目的比较寰枢椎后路手术中常用的Gallie、Brooks、Magerl双螺钉、Maged单螺钉等内固定方法单独应用或联合应用时的力学稳定性,为临床选择治疗术式提供实验依据.方法取5具新鲜冷冻人体颈椎(C1～C5)标本,固定C1和C2~C5,仅保留C1～C2之间活动.切断寰椎横韧带和齿状突,造成寰枢关节不稳定.每个标本依次行Maged单螺钉、Maged双螺钉、Gallie、Maged单螺钉 Gallie、Maged双螺钉 Gallie、Brooks固定.在生物力学试验机上应用位移控制法测定各组的稳定性,前屈和侧屈的位移定为lmm,旋转角度为30°测定正常组、损伤组及内固定各组在前屈、双侧侧屈和旋转状态下的刚度,比较内固定各组的稳定性.结果在各组内固定中,Maged双侧侧块螺钉 GaUie刚度最大,最稳定.Magerl单螺钉 Gallie和Maged双螺钉相比.在各种状态下.二者刚度均无显著性差异(P＞0.05),在旋转状态下,其刚度值分别为1.55 0.07Nm/3°和1.44 0.13Nm/3°(P＞0.05);而Maged单螺钉的刚度在各种状态下均明显低于Magerl双螺钉(P＜0.05),其中在旋转状态下分别为0.96±0.17Nm/3°和1.44±0.13Nrn/3°(P＜0.05).结论Maged单螺钉 Gallie钢丝固定稳定性好,可替代Magerl双螺钉,而Maged单螺钉固定效果不佳,应尽量避免单独使用.     

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。     

Atlantoaxial arthrodesis using C1-C2 transarticular screw fixation in a case of Morquio syndrome

Prophylactic or therapeutic arthrodesis is recommended for atlantoaxial instability in Morquio syndrome. Occipitocervical fusion, the common approach for upper cervical fusion in Morquio syndrome sacrifices the movements at the occipitoatlantal joints. The use of C1-C2 transarticular screws for achieving C1-C2 arthrodesis, without compromising mobility at the occipitoatlantal joint in Morquio syndrome has not been reported. We report a case of Morquio syndrome with atlantoaxial instability and odontoid hypoplasia, where we successfully achieved C1-C2 arthrodesis using transarticular screws and bone graft. The advantages of this method over other methods of atlantoaxial arthrodesis in Morquio syndrome have also been discussed.     

经寰枢椎椎弓根内固定融合术治疗寰枢椎不稳

随着工伤及交通事故的增多,寰枢椎不稳较以前多见,近几年本院开展经寰枢椎椎弓根内固定融合术治疗寰枢椎不稳10例,疗效满意,现报告如下。 1临床资料 1．1一般资料 2005年9月～2007年7月,共开展了10例寰枢椎椎弓根内固定融合术,男8例,女2例;年龄为24～72岁;车祸伤6例,坠落伤3例,肿瘤1例。     

A biomechanical study of unilateral posterior atlantoaxial transarticular screw fixation

The purpose of this study was to investigate the fixation of C1-C2 instability with the use of a unilateral screw. Transarticular screw placement across C1-C2 may be contra-indicated in up to 20% of specimens on at least one side because of anatomic variations or other pathological processes. Hence the current study looks into unilateral screw fixation of C1- C2 instability. Eight cervical spine specimens, C1 through C5, were harvested from fresh human cadavers (4 male and 4 female) of average age 67 years (54-80). C1 and C2-C5 vertebrae were potted to allow motion only at the C1-C2 articulation. Cutting the transverse ligament on both sides of the odontoid and the tectorial membrane destabilized the specimens. Transarticular screw fixation of C1-C2 was performed in a manner similar to the technique described by Magerl. The stability was tested after fixation with one transarticular screw together with a posterior graft and wire. Placement of the screw was randomized, resulting in half the specimens receiving screws on the right side and the remaining half on the left side. The stiffness of the C1-C2 articulation was tested in rotation, lateral bending, flexion, and anterior translation in random order. The rotational stiffness was 1.44 +/- 0.44 N-m/deg, while lateral bending stiffness values were 2.33 +/- 1.14 N-m/mm (right bending) and 2.81 +/- 1.36 N-m/mm (left bending). The stiffness value in flexion was 0.813 +/- 0.189 N-m/mm and in translation 67.1 +/- 25.1 N/m. It was found that stability after unilateral transarticular screw fixation was less than that previously reported after bilateral transarticular screw fixation, but similar to that found with modified Brooks posterior wiring, which has been shown to provide better stability than other posterior wiring methods, and fusion rates of 96% have been reported. We concluded that C1-C2 unilateral posterior transarticular screw fixation with supplemental posterior graft and wiring would confer adequate stability in cases where bilateral screw placement is contraindicated.     

胸椎后路经关节螺钉固定的可行性研究

目的:明确胸椎后路经关节螺钉固定的解剖学可行性和技术参数,为临床应用提供参考。方法:2009年9月至2009年12月,取20具胸椎标本,男12具,女8具,仔细解剖颈部的后侧和前侧方,以清楚地暴露胸椎椎板和椎弓根。以椎板下缘向上,外缘向内各7mm为进钉点,在T1,2,T5,6,T9,10直视下置入经关节螺钉,通过CT重建,测量经关节螺钉内固定进钉角度和钉道长度。结果:胸椎后路经关节螺钉均成功置入,螺钉固定方向在矢状面呈尾倾,冠状面呈外倾。经关节螺钉固定的平均角度在矢状面尾倾(52.6±5.9)°,在冠状面外倾(12.4±2.9)°。螺钉钉道长度(22.5±1.9)mm,各固定节段间角度略有不同,差异无统计学意义(P>0.5),但上、中、下不同胸椎节段之间的钉道长度差异有统计学意义(P<0.01)。结论:胸椎后路经关节螺钉具有解剖学可行性,可以作为胸椎椎弓根螺钉固定的一种补充内固定方法,但置钉时要求较高的准确性。