前路经寰枢关节螺钉内固定术的解剖学测量及其临床意义

[目的] 为国人前路经寰枢关节螺钉内固定术提供解剖学依据.[方法] 在50套中国成人配套干燥寰枢椎标本上,对前路经寰枢关节螺钉内固定术的相关解剖学数据进行测量.[结果]前路经寰枢关节螺钉内固定术以枢椎前弓下缘与枢椎椎体侧缘交界点上方4mm处为进钉点,在矢状面上螺钉植入的最小外偏角为(10.80±2.10)°,最大外偏角为(25.13 ±3.12)°,冠状面上最小后偏角为(8.85±2.12)°,最大后偏角为(26.96 3.09)°,枢椎正中至枢椎横突孔内侧缘距离为(14.12±1.28)mm,内、外侧钉道长度分别为(17.48±2.10)mm和(25.41±2.59)mm.[结论] 前路经寰枢关节螺钉内固定术中,两侧置入螺钉的理想的钉道角度为外偏10°-25°,后倾9°-27°、理想的螺钉长度为17～25 mm,由枢椎前缘正中向外分离显露不宜超过14 mm.     

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创伤性寰-枢椎不稳的前期研究

目的：提出一种治疗创伤性寰枢椎不稳的新手术方法——前路经寰枢关节螺钉内固定术,并通过建立模拟手术模型和评价安全性,验证其临床应用的可行性。方法：在１７具人体标本的术前颈椎Ｘ线片上作５条辅助线,取右侧颌下切口,根据术前计划,经枢椎椎体－寰枢关节－寰椎侧块方向置入螺钉。在术后Ｘ线片上测量螺钉轨道参数,与术前计划参数作ｔ检验。在经寰椎横突上、下缘及枢椎上关节面下缘三个横断面上测量螺钉与椎动脉的距离。统计椎动脉、脊髓及枕颈关节损伤的例数。结果：①术前计划参数：内界角１８°±１．４°,外界角３３°±３．７°,标准外偏角２６°±２．９°,后界角３９°±４．１°,标准后倾角２４°±２．０°。②螺钉轨道实际外偏角２４°±３．５°,实际后倾角２７°±４．０°,与术前参数比较无显著性差异（Ｐ＞０．０５）。③在经枢椎上关节面下缘的横断面上螺钉与椎动脉距离最短,平均值６ｍｍ,最小值３．５ｍｍ,无椎动脉及脊髓损伤,２例枕颈关节损伤。结论：前路经寰枢关节螺钉内固定术与后路内固定术互为补充。经应用解剖研究证明其具有较高的安全性和较大的临床实用性。     

寰枢椎后路经关节螺钉内固定钉道与椎动脉的解剖学关系研究

[目的]探讨寰枢椎后路经关节螺钉内固定术钉道的安全性.[方法](1)在30套国人干燥寰枢椎标本上测量相关的解剖参数;(2)在6具国人尸体标本上行寰枢椎后路经关节螺钉内固定术,术后行X线及CT检查,观察椎动脉与钉道的解剖学关系.[结果]干燥标本上枢椎上关节面下椎动脉沟深(5.86±1.45)mm;15侧椎动脉沟延伸到枢椎上关节面下内侧1/3,达中1/3和外1/3者分别为36、9侧,其理想钉道内倾角分别为(26.4±3.44)°、(16.1±2.44)°和(15.1±2.24)°.CT图像上测得钉道与椎动脉最小距离位于枢椎椎动脉沟顶点2.75～5.78 mm.[结论]枢椎椎动脉沟的位置决定钉道的角度,在枢椎上关节面下钉道与椎动脉关系最为密切,但两者之间仍有一定的安全范围.     

前路经寰枢关节螺钉内固定术置钉安全性的CT测量研究

[目的]探讨前路经寰枢关节螺钉内固定术螺钉置入的相对安全范围,为国人行此手术提供CT解剖学依据。[方法]采用多层螺旋CT(MSCT)对20套中国成人常规福尔马林浸泡的寰枢椎标本及30例健康中国成年自愿者的寰枢椎行2.0 mm层厚扫描,1.0 mm层厚重建,在容积重建(VR)及多平面重建(MPR)图像上全方位观察并利用GE RA600 PACS工作站AW三维测量软件进行相关解剖学数据测量,最后对所得结果进行统计学分析,评价置钉安全性。[结果]前路经寰枢关节螺钉内固定术以枢椎前弓下缘与枢椎椎体侧缘交界点上方4 mm处为进针点,在相对于矢状面上螺钉置入的外偏角的参考值范围为17.69°～21.13°,相对于冠状面上螺钉置入的后倾角的参考值范围为11.75°～19.50°,内侧钉道长度的参考值范围为11.19～27.51mm,外侧钉道长度的参考值范围为15.61～31.84mm。[结论]前路经寰枢关节螺钉内固定术是安全可行的,螺钉置入时的理想钉道角度为外偏18°～21°,后倾12°～20°,螺钉长度为16～28 mm。     

经关节螺钉内固定治疗寰枢椎不稳

目的 探讨经关节螺钉内固定治疗寰枢椎不稳的疗效.方法 自2000年5月至2011年10月使用经关节螺钉内固定治疗寰枢椎不稳患者56例,男43例,女13例;年龄17 ～71岁,平均38岁.1例患者脊髓神经完全损伤,29例无脊髓神经损伤症状,26例伴有脊髓神经不全损伤,按美国脊髓损伤协会(ASIA)脊髓神经功能障碍分级:C级10例,D级16例;ASIA评分50～90分,平均(78.5±9.3)分.其中后路经关节螺钉内固定32例,在寰椎后弓与枢椎椎板表面植骨.前路经关节螺钉内固定24例,在寰椎前弓下缘和齿状突基底部之间植骨.结果 1例颈脊髓神经完全损伤患者前路经寰枢关节螺钉内固定,术后1个月死于肺部感染.其他55例患者术后获6个月至9年(平均16个月)随访,手术切口均Ⅰ期愈合.1例齿状突Ⅱ型粉碎性骨折并寰枢关节脱位患者寰枢椎前路经关节螺钉内固定并植骨,齿状突未骨性愈合,但寰枢关节纤维连接无不稳定表现.其余植骨患者均获骨性融合.26例脊髓神经不全损伤患者术后ASIA分级(C级3例,D级10例,E级13例)和评分[(92.5±8.6)分]均较术前明显改善,差异有统计学意义(P＜0.05).结论 寰枢椎经关节螺钉内固定,操作简便、费用低廉、疗效可靠,可以作为治疗寰枢椎不稳患者的有效手段.     

前路经枕寰枢关节螺钉内固定的临床解剖学研究

[目的]探讨前路经枕寰枢关节螺钉的临床应用解剖学依据。[方法]取30具国人干燥枕颈部标本,测量与经枕寰枢关节螺钉内固定术相关的解剖径线及钉道参数;并以此类数据为依据,在所测量的干燥标本上模拟行经枕寰枢关节螺钉内固定术,经X线摄片检查内固定位置并测量钉道实际角度。[结果]前路经枕寰枢关节螺钉内固定的钉道在矢状面上呈后倾,在冠状面上呈外倾。左右两侧钉道角度大小差异无统计学差异,理想外倾角为(18.15±3.70)°,理想后倾角为(24.20±4.91)°,理想钉道长度为(34.45±2.9)mm;模拟行内固定验证,术后影像学及直视下检查结果显示,螺钉钉道均经过枕寰枢关节,角度均在此范围内,无穿出骨质者。[结论]采用前路经枕寰枢关节螺钉行枕颈融合内固定在解剖上是可行的。     

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。     

寰枢椎经关节螺钉治疗寰枢椎不稳定的安全性评估

目的分析寰枢椎经关节螺钉治疗寰枢椎不稳定患者的手术疗效和安全性,并探讨提高安全性的措施。方法对2000年3月～2004年12月行寰枢椎经关节螺钉固定术的23例上颈椎损伤患者进行随访,了解术后寰枢椎融合的情况,比较手术前后颈痛的VAS评分变化,了解椎动脉损伤和其它并发症的发生情况。结果所有患者平均随访32．1个月,融合率为91．3%；术前CT发现有3例患者(13．0%)单侧椎动脉高跨；有1例患者出现单侧椎动脉疑似损伤；颈痛VAS评分由术前平均8．3分,随访时为3．2分,差异有显著性意义(P＜0．05)。结论使用寰枢椎经关节螺钉治疗寰枢椎损伤融合率高,疗效满意,在术前进行CT重建排除解剖异常、设计个性化的最佳进钉点和进钉途径可最大程度地减少椎动脉损伤的可能。     

人工寰齿关节寰枢椎部件固定钉道的影像学分析

目的 探讨自行设计的人工寰齿关节( AAOJ)在寰枢关节骨性标本上置换后寰枢椎部件固定螺钉通道的安全性和可行性.方法 在32具正常成年人尸体寰枢关节湿性标本上行人工寰齿关节置换术后,行寰枢椎薄层CT扫描及三维重建,测量与AAOJ内固定的相关指标,并观察寰枢椎部件固定螺钉通道与横突孔、椎动脉沟、椎管等重要解剖结构安全空间.结果 寰椎部件固定螺钉的长度(L)为(21.5±3.7) mm,寰椎部件固定螺钉外倾角(d)为(12.9±4.8)°,寰椎部件固定螺钉下倾角(δ)为(3.0±1.2)°.枢椎部件固定螺钉的长度(S)是(28.6±3.7) mm,枢椎部件固定螺钉的外倾角度(β)是(22.6±4.3)°,枢椎部件固定螺钉的下倾角度(θ)是(15.8±2.6)°.结论 固定人工寰齿关节寰枢椎部件的螺钉通道与横突孔、椎动脉沟、椎管等重受解剖结构之间有安全空间范围.     

颈椎后路“组合式”内固定治疗寰枢关节不稳或脱位的临床疗效

目的:评价颈椎后路“组合式”内固定治疗寰枢关节不稳或脱位的临床效果。方法:回顾分析因颅椎区骨发育畸形、血管变异或者常规固定方式失败而实施寰枢椎后路“组合式”内固定术患者共58例,其中男性24例,女性34例;年龄7~75岁,平均47.8±14.7岁。术前诊断寰枢关节不稳33例,寰枢关节脱位25例。合并颈脊髓功能损害者32例(JOA 8~16分,平均13.2±1.8分)。采用的内固定方式包括寰枢椎弓根螺钉、经寰枢侧块关节螺钉(Magerl技术)、枢椎椎板螺钉、下颈椎侧块螺钉及下颈椎棘突螺钉。58例“组合式固定”患者中,45例应用2种内固定方式组合,9例应用3种方式组合,4例应用4种方式组合。使用“组合式固定”的原因包括:枢椎段椎动脉高跨、枢椎椎弓根细小或椎体发育不良、颈椎椎弓根变薄(颈椎融合畸形患者)、枢椎椎弓根骨质疏松明显以及医源性枢椎椎弓骨折等。观察手术融合率及并发症,并比较手术前后的脊髓功能。结果:全部病例术中均未出现脊髓及血管损伤。随访时间24~72个月,平均36.8±10.5个月。57例(98.3%)未出现内固定松动或断裂并获得骨性融合,1例发生内固定松动造成未融合。术前合并颈脊髓功能损害者32例,术后脊髓功能均获得不同程度改善(术后JOA 11~17分,平均15.2±1.5分)。6例患者出现了并发症,包括伤口感染延迟愈合、脑脊液漏以及内固定松动。结论:针对合并颅椎区骨发育畸形、血管变异或者常规固定方式失败的寰枢椎不稳或脱位患者,合理选择“组合式”内固定治疗是安全、有效的。     

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。     

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.     

C1-C2 transarticular screw fixation for atlantoaxial instability: a 6-year experience.

OBJECTIVE: We review a 6-year, single-center experience using the technique of C1-C2 transarticular screw fixation for atlantoaxial instability in 75 consecutive operations. METHODS: The study group was composed of 43 men and 32 women, with a mean age of 44 years (range, 8-76 yr). Each patient had documented atlantoaxial instability. In 28 patients (37%), atlantoaxial instability was a result of trauma; in 22 patients, (29%), it was a result of rheumatoid arthritis; in 16 patients (21%), it was a result of prior surgery; and in 9 patients (12%), it was a result of congenital abnormalities. All patients underwent stabilization with C1-C2 transfacetal screws and a posterior interspinous construct. Nine patients had unilateral screws placed. Postoperatively, the patients were maintained in a rigid cervical orthosis for a mean of 11 weeks (range, 8-15 wk); five patients were immobilized with halo fixation for a mean of 13 weeks (range, 10-16 wk). The mean follow-up period was 2.4 years (range, 1-5.5 yr). RESULTS: Osseous fusion was documented in 72 patients (96%). There were no hardware failures; however, three patients developed pseudarthrosis. Two superficial wound infections (one at the graft site and one at the cervical incision site) required antibiotic therapy. Four patients had transient suboccipital hypesthesia. No instances of an errant screw, dural laceration, or injury to the vertebral artery, spinal cord, or hypoglossal nerve were noted. CONCLUSION: C1-C2 transarticular screw fixation supplemented with an interspinous construct yielded a 96% fusion rate, with a low incidence of complications. We attribute our successful outcomes to careful preoperative assessment and meticulous surgical technique.     

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.     

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.     

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.     

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。     

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.