Gallie结合单侧Magerl内固定法治疗寰枢椎不稳的生物力学研究

目的 对Gallie+单侧Magerl内固定技术治疗寰枢椎不稳进行生物力学评估.方法 10具成年国人甲醛固定的枕颈(C0～C4)标本,对寰枢椎不稳模型分别行Gallie内固定、Gallie+单侧Magerl内固定、双侧Magerl内固定,在颈椎三维运动试验机上对颈椎施加2.0 N×M纯力偶矩,产生前屈/后伸,左/右侧屈和左/右旋转6种生理运动,测量其三维运动范围(ROM).结果 单侧Magerl+Gallie法固定,其屈/伸ROM为1.66度,侧屈为0.5l度,轴向旋转为6.22度,与Gallie固定法比较,ROM分别减少78%、86%、69%,差异有统计学意义(P＜0.05).双侧Magerl法固定,其屈/伸ROM变为1.48度,侧屈为0.46度,轴向旋转为5.38度,与单侧Magerl+Gallie法比较,ROM减少其差异无统计学意义(P＞0.05).结论 Gallie+单侧Magerl固定法治疗寰枢椎不稳的生物力学稳定性与双侧Magerl法接近.     

Biomechanical evaluation of atlantoaxial transarticularscrew fixation technique

Ｐｏｓｔｅｒｉｏｒａｔｌａｎｔｏａｘｉａｌｆｉｘａｔｉｏｎｔｅｃｈｎｉｑｕｅｓａｒｅｎｏｗｗｉｄｅｌｙａｃｃｅｐｔｅｄｉｎｍａｎａｇｅｍｅｎｔｏｆｔｒａｕｍａｔｉｃｏｒｐａｔｈｏｌｏｇｉｃａｔｌａｎｔｏａｘｉａｌｉｎｓｔａｂｉｌｉｔｙ .Ａｍｏｎｇｔｈｅｍ ,Ｇａｌｌｉｅ ｓｗｉｒｉｎｇ ,Ｂｒｏｏｋｓ ｏｒｍｏｄｉｆｉｅｄＢｒｏｏｋｓ ｗｉｒｉｎｇ ,ａｎｄＨａｌｉｆａｘｉｎｔｅｒｌａｍｉｎａｒｃｌａｍｐｆｉｘａｔｉｏｎａｒｅｍｏｒｅｃｏｍｍｏｎａｎｄｐｒｏｖｅｄｔｏｂｅｓｕｐｅｒｉｏｒｔｏｏｔｈｅｒｅ…     

Atlantoaxial stabilization with the use of C1-3 lateral mass screw fixation. Technical note

Atlantoaxial stabilization has evolved from simple posterior wiring to transarticular screw fixation. In some patients, however, the course of the vertebral artery (VA) through the axis varies, and therefore transarticular screw placement is not always feasible. For these patients, the authors have developed a novel method of atlantoaxial stabilization that does not require axial screws. In this paper, they describe the use of this technique in the first 10 cases. Ten consecutive patients underwent the combined C1-3 lateral mass-sublaminar axis cable fixation technique. The mean age of the patients was 62.6 years (range 23-84 years). There were six men and four women. Eight patients were treated after traumatic atlantoaxial instability developed (four had remote trauma and previous nonunion), whereas in the other two atlantoaxial instability was caused by arthritic degeneration. All had VA anatomy unsuitable to traditional transarticular screw fixation. There were no intraoperative complications in any of the patients. Postoperative computed tomography studies demonstrated excellent screw positioning in each patient. Nine patients were treated postoperatively with the aid of a rigid cervical orthosis. The remaining patient was treated using a halo fixation device. One patient died of respiratory failure 2 months after surgery. Follow-up data (mean follow-up duration 13.1 months) were available for seven of the remaining nine patients and demonstrated a stable construct with fusion in each patient. The authors present an effective alternative method in which C1-3 lateral mass screw fixation is used to treat patients with unfavorable anatomy for atlantoaxial transarticular screw fixation. In this series of 10 patients, the method was a safe and effective way to provide stabilization in these anatomically difficult patients.     

C1-C2 transarticular screw fixation: technical aspects.

OBJECTIVE: I review posterior atlantoaxial fusion with transarticular screw fixation, including indications, complications, and operative technique, emphasizing my experience. METHODS: The indications for C1-C2 transarticular screw fixation include traumatic injuries to the atlantoaxial complex, instability resulting from inflammatory disease (rheumatoid arthritis), and congenital abnormalities (os odontoideum). All patients underwent stabilization using cannulated C1-C2 transfacetal screws by the method described by Magerl. Supplemental interspinous fusion with bicortical autologous iliac crest graft and titanium cable was used to restore the posterior tension band by use of the method described by Sonntag's group. Preoperatively, all patients underwent imaging with plain radiographs, magnetic resonance imaging, and axial computed tomography. Patients were maintained in a rigid cervical orthosis postoperatively. RESULTS: Measures used to improve safety and efficacy include patient positioning, fluoroscopic guidance, preoperative magnetic resonance imaging, axial computed tomography, and open reduction of C1-C2 subluxation before screw passage. In this series of 75 patients, fusion was obtained in 72 patients (96%). There were no instances of vertebral artery injury, errant screw placement, instrumentation failure, dural laceration, spinal cord injury, or hypoglossal nerve injury. CONCLUSION: C1-C2 transarticular screw fixation with a posterior tension band construct provides excellent fusion rates with few perioperative complications. Preoperative imaging and meticulous surgical technique improve outcomes.     

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.     

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。     

Accuracy of atlantoaxial transarticular screw insertion

STUDY DESIGN: The accuracy and safety of atlantoaxial transarticular screw insertion were evaluated in clinical cases. OBJECTIVES: To evaluate the accuracy and safety of atlantoaxial transarticular screw insertion under lateral fluoroscopic monitoring without opening the joint. SUMMARY OF BACKGROUND DATA: Atlantoaxial transarticular screw fixation has been reported to be biomechanically superior to posterior atlantoaxial wiring techniques. Several clinical series have been reported in the literature. In some reports, the risk of screw insertion in this technique has been pointed out. MATERIALS AND METHODS: Fifty-six consecutive patients with atlantoaxial instability were treated by transarticular screw fixation. One hundred twelve screw insertions in these 56 patients were assessed by surgical record and computed tomographic examination. One screw could not be inserted because of the difficulty of adequate placement during operation; 111 screws were therefore inserted. Adequate position was defined as when the screw perforated the lateral atlantoaxial joint. RESULTS: In this series, neither vertebral artery injury nor spinal cord injury was experienced clinically. One guide wire was broken during drilling with a cannulated drill. Computed tomographic examination demonstrated that 106 screws perforated the atlantoaxial joint. Therefore, 95.5% of screws were adequately positioned. There were two screws positioned lateral to the joint, two medially, and one anteroinferiorly to the joint. CONCLUSIONS: Atlantoaxial transarticular screw insertion using image intensifier without opening the lateral joint was performed safely, but not accurately, in all cases.     

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.     

Posterior C2 fixation using bilateral, crossing C2 laminar screws: case series and technical note

Rigid screw fixation of the axis, for either atlantoaxial fixation or for incorporation of C2 into subaxial cervical constructs, provides significant stability and excellent long-term fusion results but remains technically demanding due to the danger of injury to the vertebral artery. Anatomic variability of the foramen transversarium in the body of the axis can preclude safe transarticular C1-C2 screw placement in up to 20% of patients. Although more recent methods of C2 screw fixation with pedicle screws allow safer fixation in a higher number of patients, there remains a significant risk to the vertebral artery with C2 pedicle screw placement. The author describes a novel technique of C2 rigid screw fixation using bilateral, crossing C2 laminar screws, not previously reported in the literature, which does not place the vertebral artery at risk during C2 fixation. This technique has been successfully used by the author in cases of craniocervical and atlantoaxial fixation as well as for incorporation of C2 into subaxial fixations. The technique is illustrated, and the author's initial experience in treating 10 patients with crossing, bilateral C2 aminar screws for indications of trauma, neoplasm, pseudarthrosis, and degenerative disease is reviewed. The possible advantages of C2 fixation with C2 laminar screws are discussed.     

Mini-open percutaneous transarticular screw fixation for acute and late atlantoaxial instability

The treatment of atlantoaxial instability by means of posterior transarticular screw fixation combined with a Gallie fusion is an established method when direct anterior odontoid screw fixation is not indicated or has failed. In this retrospective study, the results of a modified percutaneous mini-open transarticular C1-C2 screw fixation are presented. Between February 1998 and March 2006, 47 patients with acute or late (after failed conservative treatment) atlantoaxial instability were treated with the modified technique. Their average age was 74.9 years. There were no intraoperative injuries to neural structures or blood vessels; 96.8% of the screws were placed correctly. A revision operation was necessary in one patient because of infection at the graft donor site. No patient experienced a neurological complication. Three patients died during hospitalisation, 6 others later on; 6 could not be traced, leaving thirty-two patients or 68% available for follow-up. The average clinical follow-up was 42 months (range: 12 to 91). The results with respect to the pain and activity status were good or excellent in more than 90% of cases. The radiographic follow-up averaged 25 months (range: 12 to 75). Bony fusion was documented in all cases. The modified technique of transarticular screw fixation presented here is a safe and functionally satisfactory method of achieving stabilisation of the atlantoaxial complex. Special cannulated instruments are not required. This mini-open transcutaneous technique is an alternative to the conventional open procedure, and reduces operation time as well as blood loss.     

寰枢椎后路经关节螺钉固定术

目的评价参照枢椎椎管内壁行寰枢椎后路经关节螺钉固定（Naged技术）的可行性。方法2002年1月～2005年1月，对31例寰枢椎不稳患者行后路经关节螺钉内固定术，男18例，女13例；平均年龄36．8岁。螺钉置入方法：紧贴枢椎椎管内壁确定距离中线的距离，以枢椎椎板下缘上2帅为进针高度，两线交叉点即为螺钉进针点。螺钉平行矢状面，指向寰枢关节面后缘高度，通过C型臂机侧位像确认螺钉向上倾斜角度。术后结合正、侧位x线片、螺旋CT三维重建及断层扫描图像，评价螺钉置入准确程度。根据螺钉与寰枢椎关节面的位置关系分为A、B、C三区，A区螺钉通过寰椎下关节面；B区螺钉在关节面的前方或后方（前方为B1，后方为B2）；C区为螺钉在关节面的内侧或外侧（内侧为C1，外侧为C2）。结果共置入60枚螺钉。术中无椎动脉、颈脊髓、颈神经根及颅神经损伤。所有患者获得6～18个月（平均9个月）的随访，植骨融合时间为3～12个月，平均5个月，颈脊髓及神经根症状改善明显者3例，部分改善者5例，无改善者1例，无神经症状加重患者。枕颈部疼痛完全缓解者8例，部分缓解者6例，无缓解者2例。60枚螺钉中，A区58枚（96．7％），B1区2枚（3．3％），无B2及C区螺钉。结论参照枢椎椎管壁行寰枢椎后路经关节螺钉固定是安全可靠的。     

Transarticular atlanto-axial screw fixation for treatment of C1-C2 instability

Posterior transarticular screw fixation of the C1-C2 complex has become an accepted method of arthrodesis for patients requiring posterior C1-C2 fusion. Since 2000, four patients (2 males and 2 females) were treated with this surgical approach for management of atlantoaxial instability, including odontoid fracture with unilateral C1-C2 luxation, odontoid pseudarthrosis, complex congenital malformation of the craniovertebral junction and rheumatoid arthritis. All patients underwent stabilization with 2 transarticular C1-C2 screws, without any posterior interspinous graft. Patients were maintained in a rigid cervical orthesis 3 months postoperatively. Results were good, without any complication, after a short mean follow-up (8 months). Technical aspects of the technique are reported, The risk of screw malpositioning and vertebral artery or neural injury is minimal and can be lowered by using preoperative CT scan and MRI, and by using intraoperative fluoroscopy. Transarticular C1-C2 screw fixation proves to be a major surgical approach for treatment of atlantoaxial instability.     

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.     

Anatomic and biomechanical assessment of transarticular screw fixation for atlantoaxial instability.

The purpose of this study is to elucidate anatomically the atlantoaxial transarticular screw fixation described by Magerl in 1979 and compare it biomechanically with Gallie wiring. Five human C1-C2 specimens were tested in flexion/extension and rotation intact, then after wiring and screw fixation. Mean screw length was 39 mm, 25 mm in the C2 lamina and 14 mm in the lateral mass. Angular displacement of screwed specimens was significantly less than control or wired groups. Stiffness at 0-0.5 Nm loads was significantly greater for screwed specimens than for wired or controls (101 +/- 49 Nm, 10.3 +/- 9.2 Nm, and 1.96 +/- 0.18 Nm, respectively). All specimens withstood 5 Nm in flexion and extension without failure. Screw fixation provides stability comparable to Gallie wiring and is stiffer at low-range forces and rotational angles.     

Anterior retropharyngeal fixation C1-2 for stabilization of atlantoaxial instabilities: study of feasibility, technical description and preliminary results

Posterior transarticular screw fixation C1-2 with the Magerl technique is a challenging procedure for stabilization of atlantoaxial instabilities. Although its high primary stability favoured it to sublaminar wire-based techniques, the close merging of the vertebral artery (VA) and its violation during screw passage inside the axis emphasizes its potential risk. Also, posterior approach to the upper cervical spine produces extensive, as well as traumatic soft-tissue stripping. In comparison, anterior transarticular screw fixation C1-2 is an atraumatic technique, but has been neglected in the literature, even though promising results are published and lectured to date. In 2004, anterior screw fixation C1-2 was introduced in our department for the treatment of atlantoaxial instabilities. As it showed convincing results, its general anatomic feasibility was worked up. The distance between mid-sagittal line of C2 and medial border of the VA groove resembles the most important anatomic landmark in anterior transarticular screw fixation C1-2. Therefore, CT based measurements on 42 healthy specimens without pathology of the cervical spine were performed. Our data are compiled in an extended collection of anatomic landmarks relevant for anterior transarticular screw fixation C1-2. Based on anatomic findings, the technique and its feasibility in daily clinical work is depicted and discussed on our preliminary results in seven patients.     

应用经关节螺钉固定在寰枢关节不稳中的生物力学研究与临床应用

目的 探讨后路经关节螺钉固定(Magerl技术)加植骨融合治疗寰枢关节不稳定的生物力学特性及其临床价值.方法 生物力学研究:取新鲜冰冻尸体标本30具,随机分成5组:完整标本组、寰枢椎不稳实验模型组、寰枢椎后路椎弓根螺钉固定组、寰枢椎经关节螺钉固定组及寰枢椎经关节螺钉联合Brooks钢丝固定组,每组各6具.标本施加±1.5N·m纯力偶矩作为加载的最大力矩,模仿前屈、后伸,左、右侧弯,左、右轴向旋转6种生理性运动,测量各种生理性运动的活动范围(ROM)和中性区(NZ)值.应用SPSS 11.0软件进行统计分析,比较组间差异.临床研究:2000年2月至2005年1月应用寰枢椎经关节螺钉(Magerl技术)固定、C1.2棘突间植骨融合术治疗寰枢椎不稳患者23例,男16例,女7例;年龄17～62岁,平均38.6岁;先天性畸形致脱位3例,外伤性脱位20例.所有患者进行定期随访和影像学检查,评估颈椎稳定性和植骨融合率.结果 标本生物力学测试结果表明:屈伸稳定性、侧弯稳定性和轴向稳定性均为寰枢椎经关节螺钉联合Brooks钢丝固定组＞寰枢椎经关节螺钉固定组＞寰枢椎椎弓根螺钉固定组＞寰枢椎完整标本组＞寰枢椎不稳模型组,组间差异有统计学意义.临床研究表明:23例共放置经关节螺钉46枚;无一例发生椎动脉损伤、脊髓损伤或舌下神经麻痹等并发症.23例患者均获随访,随访时间4～36个月,平均15个月;随访中2例患者主诉旋转活动部分受限;影像学检查提示所有患者植骨全部融合.结论 单纯的Magerl螺钉固定失稳的寰枢关节具有足够坚固的生物力学性能,临床上结合棘突间植骨可达到满意的骨性融合.     

Atlantoaxial transarticular screw fixation and posterior fusion using ultra-high-molecular-weight polyethylene cable

This article attempts to evaluate the effectiveness of the ultra-high-molecular-weight polyethylene (UHMW-PE) cable system in atlantoaxial transarticular screw fixation and posterior fusion through the clinical results of 10 postoperative patients with atlantoaxial subluxation secondary to rheumatoid arthritis. Among them, one patient with only one screw placed owing to an anomalous vertebral artery had the correction loss of the 3-mm atlas-dens interval after surgery. Another patient had a second operation to remove the screw and cable after 2 years 11 months because a unilateral transarticular screw had come to protrude through the lateral mass of the atlas ventrally. All patients had achieved C1-C2 osseous fusion without any complications associated with this cable system. The UHMW-PE cable is a very useful material as sublaminar wiring in atlantoaxial transarticular screw fixation and posterior fusion.     

Transarticular screw fixation for atlantoaxial instability - modified Magerl's technique in 38 patients

Background  

Symptomatic atlantoaxial instability needs stabilization of the atlantoaxial joint. Among the various techniques described in literature for the fixation of atlantoaxial joint, Magerl's technique of transarticular screw fixation remains the gold standard. Traditionally this technique combines placement of transarticular screws and posterior wiring construct. The aim of this study is to evaluate clinical and radiological outcomes in subjects of atlantoaxial instability who were operated using transarticular screws and iliac crest bone graft, without the use of sublaminar wiring (a modification of Magerl's technique).     

寰枢椎不稳的后路内固定治疗

目的　介绍寰枢椎不稳的后路内固定治疗的新方法。方法　 18例寰枢椎不稳患者经后路治疗 ,其中Apofix9例 ,Apofix +C1,2 经关节螺钉 9例。结果　共放置经关节螺钉 17枚 ,1例因放置过程中引起大出血 ,仅进行了单侧放置。术后并发感染 2例 ,经清创后愈合 ,无内固定失败和椎动脉及脊髓损伤等并发症。随访 5～ 16月 ,植骨全部融合。结论　Apofix和C1,2 经关节螺钉技术是治疗寰枢椎不稳的有效方法 ,可提供有效的固定和提高植骨融合率。     

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.