人工寰齿关节置换术对寰枢关节三维运动的影响

目的：评价人工寰齿关节置换术对寰枢关节稳定性和运动功能的影响。方法：12具新鲜尸体枕颈部标本，采用脊柱三维运动立体测量系统对其完整状态，齿状突切除术后和人工寰齿关节置换术后进行三维运动范围，中性区和弹性区等指标的测试。结果：人工寰齿关节置换术后，屈伸，侧屈和旋转运动的中性区以及屈伸和伸屈运动范围较齿状突切除术后明显减小，各运动范围和中性区接近正常状态。结论：在术后即刻，人工寰齿关节置换术基本能达到既稳定寰枢关节又保留其运动功能的双重目的，但是，对人工寰齿关节置换术后寰枢关节的详细运动形式是否完全符合生理要求尚不能定论。     

寰椎齿状突人工关节置换的生物力学研究

[目的]测试寰椎齿状突人工关节置换后寰枢椎的稳定性和功能.[方法]将10例新鲜的成人头颈部标本制备成生物力学实验模型,对每一标本分别测定完整状态、减压术后、人工关节置换术后以及疲劳实验后4种状态下的运动范围、中性区和刚度.[结果]减压术后,在前屈、后伸、左右侧屈及左右旋转等方向较完整状态运动范围、中性区明显增大(P＜0.05).而刚度则显著减弱(P＜0.05);人工关节置换术后及疲劳实验后与减压术后相比前屈、后伸、左右侧屈及左右旋转的运动范围和中性区明显减小(P＜0.05),刚度显著增强(P＜0.05);人工关节置换术后及疲劳实验后与完整状态相比前屈、后伸、左右侧屈的运动范围和中性区明显减小(P＜0.05),刚度显著增强(P＜0.05),与完整状态相比左右旋转的运动范围无显著差异(P＞0.05),中性区增大(P＜0.05),刚度减小(P＜0.05).[结论]实验证实作者设计、制造出的人工寰椎齿状突关节在形态学和动力学两方面进行仿生,具有置放稳定、操作简便、不易造成副损伤以及低磨损等特点,对以往齿状突切除、脊髓减压后需要使用前路或(和)后路寰枢椎融合的患者,提供了另一种术式的选择.     

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.     

人工寰齿全关节置换后对寰枢关节稳定性和三维运动生物力学评价

目的 探讨人工寰齿关节置换后对寰枢关节稳定性和三维运动的生物力学性能.方法 选用12具新鲜尸体颈椎标本(包括枕骨基底部和C1～C4颈椎节段)置入1.53 Nm载荷下,依次轮流测试其完整状态、前路减压术后、Magerl螺钉固定后、人工寰齿关节置换后、疲劳实验后C1、C2节段标本的三维运动范围(ROM).结果 人工寰齿关节置换后,寰枢关节旋转运动范围和中性区接近正常状态,但屈伸和侧屈运动范围较前路减压术后和正常状态明显减少,差异有统计学意义(P＜0.05).在控制属伸和侧屈方向上,人工寰齿关节置换后同Magerl螺钉固定后表现出了最小的ROM(P＞0.05),但在控制寰枢关节旋转方向上,两者差异有统计学意义(P＜0.05).各进行2000次屈伸、侧屈和旋转疲劳实验后对人工寰齿关节置换后三维运动范围无明显影响,差异无统计学意义(P＞0.05).结论 自行研制的人工寰齿关节置换后既能重建寰枢关节良好的即刻稳定性又能保留其关节运动功能.     

人工寰齿关节置换与Magerl经关节螺钉固定的生物力学比较

[目的]测试人工寰椎齿状突关节置换后寰枢椎的稳定性和功能,并与Magerl经关节螺钉固定进行比较.[方法]将12例新鲜的成人头颈部标本随机分为两组,第1组在齿状突切除术后使用人工寰齿关节置换;第2组在齿状突切除术后使用Magerl经关节螺钉固定.对两组的每一标本分别测定完整状态、人工关节置换术后或经关节螺钉固定后的运动范围和中性区.[结果]人工关节置换术后与完整状态相比前屈、后伸、左右侧屈的运动范围和中性区明显减小(P＜0.05),左右旋转的运动范围无显著差异(P＞0.05),中性区增大(P＜0.05).Maged经关节螺钉固定后与完整状态相比前屈、后伸、左右侧屈及左右旋转的运动范围和中性区均明显减小(P＜0.05).人工关节置换术后及Magerl经关节螺钉固定后两组在前屈、后伸及左右侧屈的ROM稳定指数和NZ稳定指数相比均无显著差异(P＞0.05).[结论]实验证实在齿状突切除后,进行自行设计的人工寰椎齿状突关节置换可取得与Magerl经关节螺钉固定相似的前屈、后伸及左右侧屈稳定性,重要的是与完整状态相比左右旋转的运动范围无显著差异,最大限度的保留了寰枢复合体重要的旋转功能,对以往齿状突切除、脊髓减压后需要使用寰枢椎融合的患者,提供了另一种术式的选择.     

新型寰枢椎固定组合的生物力学测试

[目的]采用尸体标本测试枢椎椎板螺钉联合新型寰椎椎板钩内固定系统的生物力学稳定性.[方法]采用6具新鲜尸体颈椎标本(C0-3),分别测试完整标本模型(完整组)、寰枢椎不稳标本模型(失稳组)、双侧寰枢椎经关节螺钉联合Gallie固定植骨模型(bTFS+G组)、双侧寰枢椎经关节螺钉联合新型寰椎椎板钩固定植骨模型(bTFS+...     

枕颈部后路不同内固定的生物力学比较

目的评价不同内固定重建枕颈部稳定性的生物力学性能。方法12具新鲜人体枕颈部标本,在标本完整、枕寰枢不稳、枕颈部植骨块钛缆固定(A组)、枕颈部经关节螺钉内固定(B组)、SUM-MIT枕颈部内固定系统固定(C组)五种状态下,依次用脊柱三维运动测量系统测试其OcC1、C1,2节段的运动参数。同时对固定后的OcC1经关节螺钉(OcC1TA组)、C1,2经关节螺钉(C1,2TA组)、枢椎椎弓螺钉(C2IS组)和枕骨螺钉(Oc Screw组)在生理载荷下三维六自由度运动时,运用电测法测定四种螺钉的拔出应力,并行统计学分析。结果在OcC1节段,B组在屈伸运动中的运动范围和中性区显著大于C组。在侧屈和旋转运动中,A组的运动范围和中性区均明显大于B、C组。在C1,2节段,B组各方向运动的运动范围和中性区均明显小于A组。B组在旋转运动中的运动范围和中性区均显著小于C组。电测法结果显示,侧屈状态下所有螺钉局部应变均接近0;前屈和旋转时螺钉承受不同程度的拉应力,后伸时螺钉承受压应力。Oc Screw组在屈伸和旋转运动状态下,所承受的任何载荷应力均大于其他三种置钉方法。结论枕颈部后路经关节螺钉内固定和SUMMIT枕颈内固定在控制旋转和侧屈的稳定性上有优点。枕骨螺钉承受的拉应力最大,生理环境下枕骨螺钉可能更易发生松动和断裂。     

经寰枢关节间隙螺钉和寰椎椎板钩内固定的力学稳定性

目的评价双侧经寰枢关节间隙螺钉和寰椎椎板钩内固定的力学稳定性。方法将6具新鲜尸体颈椎标本（包括枕骨基底部和C1-C4颈椎节段）置于1．5Nm载荷下，测量C1，2节段的三维运动范围（range of motion，ROM）。标本依Gallie内固定、双侧经寰枢关节间隙螺钉和Gallie内固定、双侧经寰枢关节间隙螺钉内固定、双侧经寰枢关节间隙螺钉和寰椎椎板钩内固定、双侧寰椎侧块螺钉和枢椎椎弓根螺钉内固定的顺序实施固定，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，其中双侧经寰枢关节间隙螺钉和寰椎椎板钩内固定组在屈伸运动方向上也具有最小的ROM。寰椎侧块螺钉和枢椎椎弓根螺钉内固定组在旋转方向上ROM大于单纯经寰枢关节间隙螺钉内固定组，但在侧屈和屈伸方向上接近经寰枢关节间隙螺钉，差异无统计学意义；其在侧屈和旋转方向上ROM均小于Gallie内固定组，差异有统计学意义。结论双侧经寰枢关节间隙螺钉和寰椎椎板钩“三点”内固定具有最强的生物力学稳定性。虽然双侧寰椎侧块螺钉和枢椎椎弓根螺钉内固定在生物力学稳定性上不及“三点”内固定，但明显优于Gallie内固定。     

新型寰枢椎内固定系统的生物力学评价

目的 评价一种新型寰枢椎内固定系统的生物力学性能.方法 选取12头猪颈椎标本制作寰枢椎不稳模型,采用该新型内固定系统进行固定,测量三维运动范围,并与寰枢椎椎弓根钉棒系统进行比较.结果 新型寰枢椎内固定系统的特点是设计新颖、操作简单、使用安全;生物力学实验结果表明其在旋转、屈伸及侧弯状态的活动度与寰枢椎椎弓根钉棒差异无统...     

人工寰齿关节置换术的生物力学研究

目的:评价人工寰齿关节置换术的生物力学性能,为完善人工寰齿关节的设计提供依据.方法:对正常、齿状突切除、人工寰齿关节置换术后、疲劳试验后等状态的标本进行三维角度运动范围和前后向剪切、前屈、后伸和旋转刚度测试.结果:人工寰齿关节置换术后,寰枢关节各方向运动范围和中性区接近正常状态,前屈、后伸和侧屈运动范围较齿状突切除后减小;寰枢关节剪切和前屈、后伸刚度大于正常状态,而旋转刚度小于正常状态;屈伸和旋转疲劳1 500次对三维运动范围和刚度大小无明显影响.结论:人工寰齿关节置换术基本能达到既稳定寰枢关节又保留其运动功能的双重目的,但存在松动脱落的趋势.     

Atlantoaxiale Rotation und Distanz beim Kleinkind Eine Post-mortem-Untersuchung

The aetiology of atlanto-axial rotatory subluxation is obscure. Therefore, a post mortem investigation was designed in order to evaluate the C 1-2 rotation and translation mobility and to clear the borderline between mobility and instability and to clear the role of the atlanto-axial joints in atlanto-axial rotatory subluxation. C 1-2 specimen of 2 months, 9 months and 53 months old children were used. In the intact specimen and after sequential decision of the atlanto-axial joint capsule, the atlanto-axial membrane, the transverse ligament of the atlas, and eventually the alar ligaments, the atlas was rotated and anteriorly translated over the axis. The end point of the movements was recorded radiographically. Decision of the anatomic structures increased the rotation of up to 25 degrees. The joint capsules are lax and wide thus allowing rotation with almost complete subluxation. The subluxation of atlanto-axial joints probably stays within the normal range of motion and is not a factor of atlanto-axial rotatory subluxation. Interlocking of the facets could not be observed. In atlanto-axial rotatory subluxation the atlanto-dental interval becomes asymmetric. Its radiographic projection is variable and therefore ist does not present a valuable radiographic parameter.     

后路寰椎侧块螺钉联合枢椎椎板钩内固定的生物力学稳定性

目的研究后路寰椎侧块螺钉联合枢椎椎板钩内固定的生物力学稳定性。方法取6例新鲜尸体颈椎标本,每具标本分别依次进行完整(正常组)、寰枢椎不稳(失稳组)、寰枢侧块螺钉联合枢椎椎弓根螺钉钉棒固定(Harms组)、寰椎侧块螺钉联合枢椎椎板钩固定(钉钩组)状态的生物力学测试,每组6个标本,将各标本装载在脊柱三维运动机上,分别施予1.5 N·m力矩,记录标本在前屈后伸、左右侧曲、左右旋转3个方向上的活动度(ROM),比较各组ROM。结果相对于正常组标本,失稳组标本在上述3个方向上的ROM显著增大;相较于正常和失稳组标本,Harms组和钉钩组的标本在上述3个方向上ROM显著减小;钉钩组与Harms组间在上述3个方向的ROM差异无统计学意义(P0.05)。结论后路寰椎侧块螺钉联合枢椎椎板钩内固定在生物力学稳定性上与Harms固定相似,可以起到良好的固定效果。     

环枢关节错缝的X线表现

通过对正常组和病例组环枢关节Ｘ线片的观察和分析，认为两侧齿突侧块间距的差值和齿突环椎轴线的偏离值大于１ｍｍ，旋转开口位显示环枢运动异常，并伴有颈椎病的症状和体征者，可考虑为环枢关节错缝。     

Chronic atlanto-axial instability in Down syndrome

We studied the radiographs of thirty-two patients with Down syndrome for evidence of atlanto-axial instability. One of the patients had instability in 1970 and seven had it in 1983. The interval between the atlas and the odontoid process in the patients who demonstrated motion at that interval radiographically averaged 2.78 millimeters in 1970 and 6.93 millimeters in 1983 (p less than 0.005). Four patients whose radiographs showed atlanto-axial motion in 1970 lost that motion by 1983, and in seven patients who did not show atlanto-axial instability in 1970 it developed by 1983. Atlanto-axial instability was more likely to develop in boys who were more than ten years old. Accessory upper-cervical ossicles became evident in three patients, none of whom had atlanto-axial motion. However, one of these three patients had an abnormally wide atlanto-axial interval.     

寰枢关节多层螺旋CT旋转功能位影像学观测

目的:通过测量分析正常寰枢关节在多层螺旋CT中立位及旋转功能位的各种影像征象,为临床准确诊断寰枢关节旋转半脱位提供量化标准。方法:对51例正常志愿者进行中立位、左右尽力旋转位扫描,观察测量寰齿前间隙(atlanto-dental interval,ADI),齿突侧块间隙(lateral atlanta-dental space,LADS),齿突侧块间距差值(VBLADS)及寰枢椎相对旋转角度(rotating angle of atlas on dentate,RAAD),分析比较各影像表现及解剖学特点。将51例正常志愿者分为年龄<45岁及年龄≥45岁两组,比较不同年龄段人群VBLADS及RAAD的变化及进行相关性分析。结果:51例正常志愿者通过三维重建软件显示中立位寰枢外侧关节基本对称,齿突侧块间隙不对称者40例,占78.4%.中立位齿突偏移角度范围为(3.22±0.89)°,尽力旋转位寰枢椎(atlanto-axial joint)外侧关节面呈旋转性关节面移位,相对旋转角度范围为(33.85±2.79)°。通过配对资料相关性分析得出在一定范围内寰枢椎相对旋转角度与VBLADS无相关性。<45岁及≥45岁尽力旋转位时寰枢椎相对旋转角度之间差异有统计学意义。结论:多层螺旋CT旋转功能位能清楚显示寰枢区的解剖结构及旋转功能,为诊断寰枢关节旋转半脱位提供理论依据。     

Diagnosis of acute atlanto-axial rotatory fixation

We report three cases of atlanto-axial rotatory fixation in adults. Early diagnosis was made by clinical tests showing restricted head rotation in maximal neck flexion and asymmetry of the transverse processes of the atlas, confirmed by cineradiography. Early treatment by traction may obviate long-term problems of torticollis and instability.     

Quantitative anatomic study of atlanto-odontoid joint and design of an artificial atlanto.odontoid joint for the orthopedic clinic

OBJECTIVE: To observe and measure morphological parameters of the Chinese atlanto-odontoid joint anatomically in order to provide an anatomic data for designing artificial atlanto-odontoid joint used for substituting the destroyed atlanto-odontoid joint in the orthopedic clinic. METHODS: The relative anatomic parameters of 32 sets of fresh Chinese adults'atlanto-odontoid joint specimens were measured with a digital caliper and a goniometer, including the width of anterior arch of atlas (AW), the thickness of atlas at the junction of anterior arch and lateral mass (AD), the thickness and height of anterior tubercle of atlas (AT and AH), the middle height, length and width of the lateral mass (MHL, L and LW), the height, transverse and anteroposterior distance of odontoid process (DH, DW and DD), the retroversion angle of odontoid process (beta degree),the facial angle of odontoid process (theta degree) and so on. The data were statistically analyzed in order to ascertain the morphological parameter ranges of artificial atlanto-odontoid joint. An artificial atlanto-odontoid joint was designed according to these data. The operations of anlanto-odontoid joint arthroplasty were conducted in 3 cases of adult cadaver specimens. RESULTS: The width of AW was (20.45+/-1.53) mm, AD (3.91+/-1.32) mm, AT and AH (9.43+/-1.93)mm and (10.23+/-1.32) mm, respectively, MHL and LW (13.68+/-1.38) mm and (12.98+/-1.52) mm, respectively, DH (15.25+/-2.11) mm, DW and DD (9.69+/-1.38) mm and (11.26+/-1.02) mm, respectively, beta degree (12.23+/-4.27) degree, theta degree (65.48+/-2.17) degree. The prosthesis was composed of atlas part, axis part and accessories. Neither the vertebral artery nor the medulla oblongata was injured. CONCLUSIONS: The design of artificial atlanto-odontoid joint is feasible according to these parameters. The artificial joint can not only rebuild the stability of atlanto-axial joint, but also reserve the rotation function between atlas and axis. Every part of the joint has their own parameter ranges in purpose to firm fixation, convenient operation and good motion without further injury. The prosthesis can be used for patients suffering from compression of medulla oblongata and resection of dens when it is required.     

人工寰齿关节置换术的生物力学研究

目的:评价人工寰齿关节置换术的生物力学性能,为完善人工寰齿关节的设计提供依据。方法:对正常、齿状突切除、人工寰齿关节置换术后、疲劳试验后等状态的标本进行三维角度运动范围和前后向剪切、前屈、后伸和旋转刚度测试。结果:人工寰齿关节置换术后,寰枢关节各方向运动范围和中性区接近正常状态,前屈、后伸和侧屈运动范围较齿状突切除后减小;寰枢关节剪切和前屈、后伸刚度大于正常状态,而旋转刚度小于正常状态;屈伸和旋转疲劳1500次对三维运动范围和刚度大小无明显影响。结论:人工寰齿关节置换术基本能达到既稳定寰枢关节又保留其运动功能的双重目的,但存在松动脱落的趋势。     

Multidirectional instabilities of experimental burst fractures of the atlas.

For the purpose of understanding the acute instability of a burst (Jefferson) fracture of the atlas, the authors produced the fractures experimentally and measured multidirectional flexibilities in seven cadaveric C0-C3 specimens. The flexibilities were measured by the authors' standardized method: they applied six types of physiologically pure moments (up to 1.5 Nm) and recorded the ensuing C0-C2 motions by stereophotogrammetry. The flexibility tests were performed before and after the production of the fracture. The greatest increase in flexibility due to the injury was in flexion-extension (+22.0 degrees, 41.7%). In lateral bending, the increase was 7.7 degrees, or 23.9%. The flexibility was mostly maintained in axial rotation (+4.8 degrees, 5.4%). The increase in motion was due to an increase in neutral zone in flexion-extension, and an increase in the elastic zone in lateral bending. These flexibility results of experimentally produced fractures reflect quite well the acute instabilities seen clinically.