人工寰齿关节设计依据及可行性分析

Anatomical study for the design of artificial atlanto-odontoid joint and to analysis its feasibility

目的:通过解剖和X线观察,测量国人寰齿关节以获取形态学参数,为研制能替代寰齿关节功能的人工寰齿关节提供解剖数据。方法:用电子游标卡尺和量角器测量32套正常成年人寰齿关节新鲜标本的相关参数,包括寰椎前弓宽度、前弓下缘与C2上关节面前缘间距、枢椎侧块内缘与齿状突外缘间距、寰椎前结节厚度和高度、寰椎侧块中点高度和长度、寰椎侧块宽度、齿状突高度、齿状突横径和前后径、齿状突后倾角和齿面角等23项内容。并进行统计学分析,为研制人工寰齿关节提供形态学参数范围。据此设计仿生人工寰齿关节,在3具成人尸体标本进行模拟人工寰齿关节置入手术。结果:测得寰椎前弓宽度平均为(20.45±1.53)mm,前弓下缘与C2上关节面前缘间距平均为(2.12±1.22)mm,枢椎侧块内缘与齿状突外缘间距平均(2.51±2.18)mm,寰椎前结节厚度和高度分别平均为(9.43±1.93)mm和(10.23±1.32)mm,寰椎侧块中点高度和宽度分别平均(13.68±1.38)mm和(12.98±1.52)mm,齿状突高度平均为(15.25±2.11)mm,齿状突横径和前后径平均分别为(9.69±1.38)mm和(11.26±1.02)mm,齿状突后倾角平均为(12.23±4.27)°、齿面角平均为(65.48±2.17)°。人工关节由寰椎部件、枢椎部件和配件构成。模拟手术中无椎动脉损伤和假体压迫脊髓。结论:人工寰齿关节的研制在形态学上具有可行性。人工寰齿关节的研制是既能重建寰枢关节稳定性,又能保留寰枢关节旋转功能的可行性技术。为了安放牢固、操作方便、保持运动功能以及避免副损伤,各部件参数有一定的选取范围。

Objective： Observation and measurement were done on atlanto-odontoid joint to get the morphological parameters in Chinese via dissection and X-rays. The artificial atlanto-odontoid joint is expected to be developed in order to replace the destroyed anlanto-odontoid joint. To provide anatomic data for designing artificial anlanto-odontoid joint, the data were statistically analyzed to asertain the range of morphological parameters of artificial anlanto-odontoid joint. Methods： The relative anatomic parameters of 32 fresh Chinese adults＇ atlanto-odontoid joint specimns were measured with a digital vernier caliper and a goniometer, including the width of anterior arch of atlas ; the distance between the inferior border of anterior arch and the anterior border of the superior articular surface of C2 ; the distance between the medial margin of axial lateral mass and the external margin of the odontoid process;the thickness and height of anterior tubercle of the atlas; the height and length at the middle point of the lateral mass; the width of the lateral mass;the height, transverse diameter and anteriorposterior diameter of the odontoid process;the retroversion angle of the odontoid process;the facial angle of the odontoid process and so on. The data were statistically analyzed in order to asertain the range of morphological parameters of artifiicial anlanto-odontoid joint. An artificial anlanto-odontoid joint was designed according to these data. The average anlanto-odontoid joint arthroplasty was conducted in 3 cases of adult cadaver specimens. Results： The average width of anterior arch of atlas was （ 20. 45 ±1.53 ） mm. The average distance between inferior border of anterior arch and anterior border of superior articular surface of C2 was （ 2. 12 ± 1.22 ） mm. The average distance between the middle margin of axial lateral mass and the external margin of the odontoid process was （2. 51 ± 2. 18 ） mm. The average thickness and height of anterior tubercle of the atlas were （9.43 ± 1.93 ） mm and （ 10. 23 ± 1.32） mm respectively. The average height and width at the middle point of the lateral mass was （ 13.68 ± 1.38 ） mm and （ 12. 98 ± 1.52） mm respectively. The average height of the odontoid process was （ 15.25 ± 2. 11 ） mm. The transverse and anteriorposterior diameter of the odontoid process was （9. 69 ± 1.38） mm and （ 11.26 ± 1.02） mm respectively. The retroversion angle of the odontoid process was （12. 23 ±4. 27 ）°. The facial angle of the odontoid process was （65.48± 2. 17 ）°. The prosthesis was composed of atlas part, axis part and accessories. Neither the vertebral artery nor the spinal cord was injured. Conclusion： The design of artificial anlanto-odontoid joint is feasible on morphology. The artificial joint can not only reestablish the stability of atlanto-axial joint,but also reserve the rotation function between the atlas and axis. Every part of the joint has their own range of parameters in order to finn fixation, convenient operation and good motion without complications.