寰枢椎的解剖学测量及其临床意义

Anatomical measurement of atlas and axis and its clinical significance

目的 :为寰枢椎区病损机制和手术治疗提供解剖学依据。方法 :在 15 0例中国成年人干燥寰枢椎标本上 ,对具有临床意义的数据进行解剖学测量。结果 :寰椎上关节面内倾角、下关节面外倾角及侧块内倾角两侧不对称分别占 19.3 %、10 .7%和 7.3 % ;椎动脉沟处形成沟环者占 16 .0 % ;所有横突孔的前后径和横径均大于 4mm ;后弓内侧半距仅为外侧半距的 1/2。枢椎椎弓根内倾角变异较大 (-3 .5°～2 1.5°) ;齿突腰部宽度小于 9mm者占 71.2 % ,齿突后倾角的变异较大 (0°～ 2 2°) ;2 7.5 %的椎动脉在经过枢椎侧块下方时会形成一动脉压迹沟 ,致使侧块外端和椎弓根变薄。结论 :①寰枢椎的解剖学形态与其生物力学性质及损伤机制密切相关 ;②手术时寰椎前弓向外显露不宜超过 2 0mm ,后弓切除向外不宜超过 10mm ,经寰枢外侧关节融合或内固定术应选择在关节的内侧 2 /3 ;③大部分中国人不适宜于两枚齿突螺钉内固定术 ;④ 2 7.5 %的中国人不适宜于经椎弓根螺钉固定术 ,枢椎椎弓根变异较大 ,手术前应作CT检测。

Objective: To provide morphological basis for the mechanism and surgical therapy of injury on atlas and axis. Methods: The clinical significant data were observed and measured in 150 dry atlas and axis specimens.Results: Atlas: 19.3% of the inside oblique angle of superior articular face, 10.7% of outside oblique angle of inferior articular face and 7.3% of inside oblique angle of aside massa were asymmetry.Incidence of posterior ponticulus of the atlas was 16.0%.The anteriorposterior diameter and transverse diameter were greater than four millimeter in all transverse foramen.Inside semi diameter of anterior atlantis arcus was half of the outside semi diameter of that.Axis: Inside oblique angle of vertebral pedicle and caster angle of odontoid process vary in a large range.Transverse diameter was less than 9 mm in 71.2% of odontoid process.There was an impression underlying axis aside massa in 27.5% of all specimens. Conclusion: Morphology of atlas and axis is correlated with its biomechanics and mechanism of injury.Exposure range during operation is limited in order to avoid damage of vertebral artery. Most of Chinese are unsuitable for two screw odontoid fixation.27.5% of Chinese are unsuitable for posterior atlantoaxial transarticular screw fixation.CT is indispensable before operation.