A Plate Design For C2.3 Through Anterior Approach Based On Computed Tomography And Clinical Practice

Objective: To develop a plate for C2.3through anterior approach based on the clinical practice and anatomical data of computed tomography?Methods: The anatomic parameters of C2.3 from 53 normal adults were measured by computed tomography(CT)image system,including the distance between of the the best entry points and the anterior edge of the third cervical vertebra;The height of the front edge and the center of the third cervical spine,the radius of the convex points on the two sides of the anterior edge of the Anteroinferior lip(AIL)and the central convex point of the AIL?Radius of the leading edge of the upper third of the third cervical spine;Maximum entry distance,the angle between the screw and the steel plate,the height of the steel plate,the radius of the longitudinal arc of the steel plate at the proximal end,the distance of the proximal nail entry point,and the length of the bone plate on both sides,the angle were also calculated.Paired sample t-test was used for comparing the parameters between both men and women,left and right sides.We used 2 variables for Pearson correlation analysis between the length of the needle insertion point and the anterior edge of the third cervical vertebra and other length indices.Results: Measure and determine the values of the main fixed areas of the vertebral body fractures:(1)Design of the steel plate at the vertebra: The arc length is designed to be 13 mm,the average thickness is 2mm,the outer side is an arc with a radius of 9.4mm,and the inner side is an arc with a radius of 7.15 mm,to better fit the axis.(2)The design of the third cervical vertebra of the steel plate: an arc with an arc length of 16 mm,an average thickness of 2mm,and an inner and outer radius of 10.3mm,to better fit the third cervical vertebra.(3)Design of the long axis of the steel plate: respect design an arc lengths of 18,20,and 22 mm,and arcs with a radius of 20 mm.5.All measured parameters were tested by paired t test,which showed that there was no obvious difference between Maximum entry distance of the screw,the radius of the bulge and the central bulge on both sides of the AIL,the radius of the bulge and the central bulge on both sides of AIL and Radius of the arc of the leading edge of the 3rd cervical spine,but there are statistical differences in the others data(P <0.05).We should design plates with different indexes for men and women.but,in actual design,it is found that the volume of the axis and the third cervical vertebra itself are small,so the unit of the measured value is also small.Although there are statistically differences between men and women,the actual difference between the designed steel plates is not.Obviously,the average of all anatomical data of 50 subjects was selected as the reference index,and steel plates of different sizes were evenly distributed.Conclusions: The measurement results of the anatomical parameters in this study have high accuracy.It is feasible to design a new type of plate for cervical vertebral fractures through the anterior approach.Different indexes can be designed for men and women.The anterior edge of the vertebral body may be a stable anatomical feature,and it can be measured by preoperative CT to provide a basis for determining the nail insertion point of the cervical 2 during operation.