后路经关节螺钉固定颗粒状植骨融合治疗寰枢关节不稳定

目的:探讨后路经C1、C2侧块关节螺钉固定、颗粒状松质骨植骨行寰枢关节融合治疗寰枢关节不稳的效果。方法:自1999年12月~2003年4月对58例因齿状突不连、寰椎横韧带断裂或松弛导致寰枢关节不稳定的病例施行了后路经C1、C2侧块关节的螺钉固定术,然后在C1、C2后弓间植入颗粒状松质骨。术中不用钛缆固定寰椎后弓与枢椎棘突。术后不需任何外固定。结果:无手术中损伤脊髓和椎动脉的病例。49例获得随访,时间6个月～3年10个月,平均20个月,全部获得了骨性融合。结论:当寰枢关节不稳定时用两枚螺钉由后路经C1、C2侧块关节固定即可起到足够的稳定作用;在C1、C2后弓间植入颗粒状松质骨可获得很高的融合率。     

寰枢椎后路经关节螺钉内固定治疗寰枢椎不稳定的生物力学及临床研究

目的评价寰枢椎后路经关节螺钉内固定术两种不同钉道的生物力学稳定性及疗效。方法在8例新鲜尸体标本依次轮流测试正常、Ⅱ型齿状突骨折行AO进钉点与改良进钉点两种后路钉道螺钉固定术模型三维运动范围，并在16例寰枢椎不稳定患者，采用枢椎下关节突下缘正中点为进钉点的方法行经关节螺钉固定及自体颗粒样松质骨植骨术。结果两种入钉方法均能明显减少寰枢关节的各向运动角度（P〈0．01），但两者间差异无统计学意义（P〉0．05）。经5～48个月随访，16例患者寰枢关节稳定性均获得恢复与骨融合，无并发症。结论新入钉点解剖标志明确。钉道长，能提供牢固地固定，并发症发生率低。     

Percutaneous transarticular atlantoaxial screw fixation using a cannulated screw system and image guidance.

In 2000 a cannulated screw stabilization system for posterior cervical instrumentation was introduced in our department for use in complex cervical fixation procedures. A special feature of the system is the use of thin Kirschner wires for drilling the screw paths and then placing the self-drilling, cannulated screws securely over the wires. Percutaneous application of C1-C2 transarticular screws is possible through tubes. An optional "atlas-claw" provides additional stability in cases of C1-C2 stabilization. 17 patients (10 female, 7 male, mean age 60 years) with complex cervical disorders and instability of different origin were stabilized using the Neon System (Ulrich Co., Ulm, Germany). Pathology included atlantoaxial instability based on rheumatoid arthritis (n = 12), odontoid fracture (n = 4) and os odontoideum mobile (n = 1). Computed navigation (STN 4.0, Zeiss or vector vision spine, brain lab) was used in 14 cases. Transarticular C1-C2 screw fixation was performed in 14 cases (4 patients with direct C1 massa lateralis screw fixation), craniocervical fixation (C0-C2/C3) was done in 3 patients. Percutaneous application of the C1-C2 screws was used in 7 patients. Atlas claws were applied in 8 patients. There was one medial perforation of a C2 pedicle wall and one malposition of the screw in C2 without reaching the lateral mass of C1. After a mean follow-up of 9 months there were no hardware failures and stable fusion in those cases followed after 12 months or more. Clinical results were excellent or good in 14/16 patients. Cannulated screws are an effective alternative in complex stabilization procedures of the cervical spine. The presented system is technically comfortable and allows safe percutaneous screw application as well as inclusion of computed navigation with high accuracy.     

Traumatic atlantoaxial rotatory dislocation with odontoid fracture: case report and review

STUDY DESIGN: A case of traumatic rotatory dislocation associated with odontoid fracture is reported. OBJECTIVES: To report a rare case of traumatic rotatory dislocation associated with odontoid fracture, and to discuss the mechanism underlying spinal instability and management. SUMMARY OF BACKGROUND DATA: This case is a cross between traumatic rotatory fixation and atlantoaxial rotatory dislocation. Classification of rotatory subluxation change after osteosynthesis of the odontoid process was undertaken. METHODS: A 24-year-old man sustained head and cervical injury after jumping. A Type 2 odontoid fracture without displacement was noted. RESULTS: Without further traumatic event, 1 month after injury, computed tomography scan showed posterior displacement of the odontoid fracture and Type 4 or B atlantoaxial rotatory luxation. After surgical fixation and reduction of the odontoid fracture, the rotatory subluxation classification changed and became Type 1 or A. Posterior C1-C2 arthrodesis was performed. The patient wore a Philadelphia cervical collar for 3 months and underwent physiotherapy. CONCLUSIONS: As the pivot of rotatory subluxation changed after odontoid process osteosynthesis, posterior C1-C2 arthrodesis was performed. The patient probably could have been treated in a single-stage procedure using posterior C1-C2 transarticular fixation with bicortical interspinous graft.     

Anterior C1-C2 screw fixation and bony fusion through an anterior retropharyngeal approach

We present a case that demonstrates an occasion where an alternative method of C1-C2 fusion may be used when a posterior approach limited to the atlantoaxial level is not desirable. A 22-year-old man presented with a symptomatic nonunited Brooks posterior atlantoaxial fusion following a chronically displaced type II odontoid fracture with a two-part fracture of the posterior arch of C1. An anterior retropharyngeal approach was used to perform an anterior C1-C2 fusion with screw fixation. The surgical technique, as well as the merits and indications of this infrequently used procedure, are discussed.     

Posterior fixation and fusion with atlas pedicle screw system for upper cervical diseases

Objective： To evaluate the feasibility, safety and efficacy of atlas pedicle screws system fixation and fusion for the treatment of upper cervical diseases.
Methods： Twenty-three consecutive patients with upper cervical disorders requiring stabilization, including 19 cases of atlantoaxial dislocation （4 congenital odontoid disconnections, 6 old odontoid fractures, 4 fresh odontoid fractures of Aderson Ⅱ C, 3 ruptures of the C1 transverse ligament, and 2 fractures of C1）, 2 cases of C2 tumor （instability after the resection of the tumors）, and 2 giant neurilemomas of C2-C3（instability after resection of the tumors）, were treated by posterior fixation and fusion with the atlas pedicle screw system, in which the screws were inserted through the posterior arch of C1. The operative time, bleeding volume and complications were reported. All patients were immobilized without external fixation or with rigid cervical collars for 1-3 months. All patients were followed up and evaluated with radiographs and CT.
Results： In the 23 patients, 46 C1 pedicle screws, 42 C2 pedicle screws and 6 lower cervical lateral mass screws and 2 lower cervical pedicle screws were placed. The mean operative time and bleeding volume was 2.7 hours and 490 ml respectively. No intraoperative complications were directly related to surgical technique. No neurological, vascular or infective complications were encountered. All patients were followed up for 3-36 months （average 15 months）. Firm bony fusion was documented in all patients after 3-6 months. One patient with atlas fracture showed anterior occipitocervical fusion. There was no implant failure. Conclusions： Posterior fixation and fusion of the atlas pedicle screw system is feasible and safe for the treatment of upper cervical diseases, and may be applicable to a larger number of patients.     

多种寰枢椎后路钉棒固定技术的临床组合应用

目的评价3种寰椎后路螺钉固定方法和2种枢椎后路螺钉固定方法构成的钉棒组合治疗上颈椎不稳的可行性和临床效果。方法在气管插管全麻下对132例患者施行了寰枢椎后路钉棒固定技术,寰椎进行椎弓根螺钉、部分经椎弓根螺钉或侧块螺钉固定;枢椎进行椎弓根螺钉或交叉椎板螺钉固定。结果全组病例获钉棒固定,其中寰椎螺钉固定采用椎弓根螺钉224枚,部分经椎弓根螺钉36枚,侧块螺钉4枚;枢椎螺钉固定采用椎弓根螺钉240枚,椎板螺钉24枚。术中未发生椎动脉、脊髓损伤。120例患者术后获得随访3～22个月,平均8个月,临床症状得到不同程度的改善;X线片、CT复查螺钉位置良好,无松动、断钉,植骨3～6个月后均达到满意融合。结论寰椎和枢椎螺钉可进行多重组合,为上颈椎后路提供灵活多变的短节段固定,增加了钉棒固定技术的临床适用范围。     

后路寰枢椎椎弓根钉内固定及枕颈融合术治疗上颈椎不稳27例临床分析

目的 探讨应用寰枢侧块螺钉与枢椎椎弓根钉内固定及枕颈融合术治疗上颈椎不稳的疗效.方法 对寰枢椎不稳27例患者采用寰椎侧块螺钉结合枢椎椎弓根螺钉及枕颈融合治疗.结果 27例患者均经寰枢椎螺钉或枕颈融合内固定术,其中一例颅底凹陷患者一期行经口齿状突切除术,二期行枕颈融合术,27例患者无一例发生脊髓和椎动脉损伤.所有患者均获得随访,随访3 ～17个月,平均9个月.术后3个月JOA评分13.5 ～16.9分,平均15.2分,改善率为88.4％.植骨块全部融合,无内固定断裂、松动.结论 后路寰椎侧块螺钉结合枢椎椎弓根螺钉固定及枕颈融合术具有稳定的三维固定效果,可用于治疗上颈椎不稳.     

Odontoid fractures: A retrospective analysis of 53 cases

Background:

The management of odontoid fracture has evolved but controversy persists as to the best method for Type II odontoid fractures with or without atlantoaxial (AA) instability. The anterior odontoid screw fixation can be associated with significant morbidity while delayed odontoid screw fixation has shown to be associated with reasonable good fusion rates. We conducted a retrospective analysis to evaluate the outcome of a trial of conservative management in type II odontoid fractures without atlantoaxial instability (Group A) followed by delayed odontoid screw fixation in cases in which fusion was not achieved by conservative treatment. The outcome of type II odontoid fracture with AA subluxation (Group B) was also analysed where closed reduction on traction could be achieved and in those atlantoaxial subluxations that were irreducible an intraoperative reduction was done.

Materials and Methods:

A retrospective evaluation of 53 cases of odontoid fractures treated over a 9-year period is being reported. All odontoid fractures without AA instability (n=29) were initially managed conservatively. Three patients who did not achieve union with conservative management were treated with delayed anterior screw fixation. Twenty-four cases of odontoid fractures were associated with AA instability; 17 of them could be reduced with skeletal traction and were managed with posterior fusion and fixation. Of the seven cases that were irreducible, the initial three cases were treated by odontoid excision followed by posterior fusion and fixation; however, in the later four cases, intra operative reduction was achieved by a manipulation procedure, and posterior fusion and fixation was performed.

Results:

Twenty-six of 29 cases of odontoid fracture without AA instability achieved fracture union with conservative management whereas the remaining three patients achieved union following delayed anterior odontoid screw fixation. 17 out of 24 odontoid fracture with atlantoaxial dislocation could be reduced on traction and these patients underwent posterior fusion and fixation. Optimal or near optimal reduction was achieved by on table manipulation in four cases which were irreducible with skeletal traction. Atlantoaxial stability was achieved in all cases. All cases were noted to be stable on evaluation with x-rays at six months.

Conclusions:

The initial conservative management and use of odontoid screw fixation only in cases where conservative management for 6–12 weeks has failed to provide fracture union have shown good outcome in type II odontoid fracture without AA instability rates. Intraoperative manipulation and reduction in patients where AA subluxation failed to reduce on skeletal traction followed by posterior fusion obviates the need for transoral odontoid excision.     

寰枢椎不稳的颈后路手术治疗

目的 对寰枢椎不稳的颈后路手术治疗进行探讨。方法 共78例患者,男57例,女21例;年龄3－78岁,平均42岁。其中齿突骨折（新鲜骨折、陈旧骨折、骨不连）38例,齿突游离小骨15例,寰椎横韧带断裂8例,寰枢椎肿瘤6例,枕颈部发育畸形6例,寰椎椎弓陈旧性骨折5例。78例均行颈后路手术,包括枕颈融合术32例,其中单纯植骨融合11例,辅以CD－Cervical内固定11例,Cervifix内固定10例;寰枢椎融合术46例,其中钢丝钛缆内固定37例（9例同时行寰枢椎经关节间隙螺钉内固定术）,Apofix椎板夹内固定9例。结果 78例均获随访,时间6个月－18年,平均38．4个月。骨性愈合75例,不愈合3例。术前合并神经系统症状38例,术后症状消失或基本消失20例,明显改善11例,轻度改善3例,无改善2例,加重2例。结论 对于由寰枢椎骨折脱位、畸形、肿瘤及横韧带断裂等引起的寰枢椎不稳,应早期进行后路融合术。充分控制寰枢椎活动,精心准备植骨床是保证手术成功的关键。     

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.     

Acute combination fracture of atlas and axis: "triple" anterior screw fixation in a 92-year-old man: technical note

BACKGROUND: The combination of odontoid and bilateral transarticular C1-C2 anterior screw fixation is a recent addition in treating C1-type II odontoid fractures. When feasible, it ensures early maximal stability, even if it slightly reduces the mobility of C1-C2 complex. We report a case of combination atlas-type II odontoid fracture that occurred in a 92-year-old man. The instability was treated with odontoid screw fixation and anterior bilateral C1-C2 transarticular screw fixation in a single stage. The aim of the article is to describe the feasibility of "triple" anterior screw fixation in the presence of C1-type II odontoid fracture. METHODS: The diagnosis, treatment, and outcome of a 92-year-old patient with mild tetraparesis caused by C1-type II odontoid fracture were assessed. RESULTS: Cervical x-rays, computed tomographic scan, and magnetic resonance imaging demonstrated a fracture of posterior arch of C1, associated with type II odontoid fracture and with presumable damage of C1 transverse ligament. Magnetic resonance imaging also showed a high cervical centromedullary area slightly hyperintense in T1-weighted images. Treatment consisted of odontoid and bilateral C1-C2 transarticular screw fixation with single anterior approach. The admission neurologic conditions improved and the patient was early mobilized. CONCLUSIONS: The authors suggest that in presence of C1-type II odontoid fracture, the triple anterior screw fixation has to be taken into account as salvage procedure, especially if other methods of stabilization failed or cannot be safely performed. This technique seems to be safety feasible also in old patients, as our report and the experience of others confirm.     

前路经寰枢关节螺钉内固定术治疗寰枢椎不稳定的生物力学及临床研究

目的 探讨前路经寰枢关节螺钉内固定术的生物力学稳定性及疗效.方法 8具新鲜颈椎标本,对每一标本先后行正常状态、齿状突Ⅱ型骨折、前路经寰枢关节螺钉内固定术、后路Magerl螺钉内固定术4种状态三维运动范围的测定.并对20例创伤性寰枢椎不稳定患者施行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与后路Magerl螺钉内固定术均明显减少寰枢关节各方向运动范围,经统计学检验差异无统计学意义.20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19例病例获得随访,时间7个月～3年,平均18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,固定可靠,损伤脊髓或椎动脉的风险较小.     

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.     

Anterior screw fixation of posteriorly displaced type II odontoid fractures

Posteriorly displaced Type II odontoid fractures (Type II-P) are difficult to stabilize in an anatomic position with accepted methods of posterior atlantoaxial arthrodesis. Nine patients with Type II-P odontoid fractures with 4 to 15 mm displacement were treated with anterior odontoid screw stabilization. Seven of these patients had associated fractures or defects of the posterior arch of the first cervical vertebra (C1). Atlantoaxial posterior arthrodesis in these patients would not have been possible initially because of the lack of structural integrity of the posterior arch of C1. Two patients, later in the study, had no injury to the ring of C1. The odontoid fractures were stabilized with two 4.0-mm cancellous screws inserted through an anterior approach to the neck under fluoroscopic control with the skin incision at the C5 level. Preoperative reduction of the displaced odontoid process and immediate operative stability of the atlantoaxial complex were obtained in each case. No neurological complications related to the procedure occurred. Two patients died of causes unrelated to their cervical fracture surgery. The 7 patients who survived were followed for a minimum of 6 months. Fracture union and cervical stability were demonstrated in each of the surviving patients, without evidence of screw loosening or loss of fixation. Normal range of motion of the neck was documented at follow-up in all surviving patients. Although this series represents a limited experience with this treatment technique, anterior odontoid screw fixation has significant advantages over accepted methods of cervical stabilization for Type II-P odontoid fractures.(ABSTRACT TRUNCATED AT 250 WORDS)     

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。     

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.     

寰枢椎椎弓根螺钉内固定术治疗儿童寰枢椎脱位的初步报告

目的:探讨寰枢椎椎弓根螺钉内固定手术治疗儿童寰枢椎脱位的可操作性和近期疗效。方法:2005年9月~2011年3月对16例儿童寰枢椎脱位患者采用寰枢椎椎弓根螺钉内固定术治疗,男9例,女7例;年龄5～13岁,平均9.1岁。均有枕颈部疼痛、颈部僵硬;3例有高位颈脊髓病表现,ASIA分级:D级2例,C级1例。术前均行颈椎正侧位及过伸过屈位X线片、CT和MRI检查,均诊断为寰枢椎脱位,其中寰椎横韧带断裂1例,寰枢椎骨折脱位1例,先天性齿状突畸形12例,寰枢椎固定旋转半脱位2例;颈脊髓受压5例。寰椎后弓(椎弓根)高度2.5~3.8mm,平均3.0mm;寰齿前间隙6~14mm,平均9mm。术前常规行牵引1~2周复位,完全复位7例,部分复位5例,不能复位4例。术中采用"寰椎椎弓根显露置钉法",在直视下行C1、C2置钉,复位固定,植骨融合。随访患者症状和神经功能改善情况,定期行颈椎X线片及CT复查,了解内固定及植骨融合情况。结果:16例均行双侧寰枢椎椎弓根螺钉内固定,手术过程顺利,64枚螺钉均成功置入,复位固定满意,无术中、术后神经和血管并发症。术中出血150~650ml,平均300ml;手术时间100~190min,平均130min。12例随访12~72个月,平均28.5个月,术后3~6个月寰枢椎均骨性融合;末次随访时,颈枕症状明显改善,3例术前有脊髓功能损害者均好转,2例术前ASIA分级D级者恢复到E级,1例术前ASIA分级C级者恢复到D级;未发现螺钉松动、断钉和寰枢椎再移位现象,未发现曲轴现象。结论:采用"寰椎椎弓根显露置钉法"行寰椎椎弓根螺钉内固定可操作性强,置钉安全性高;寰枢椎椎弓根螺钉内固定治疗儿童寰枢椎脱位的近期疗效满意。     

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。