Anatomy-based FEA And Clinical Research Of Lower Cervical Spine

Objective:To explore the anatomical parameter of lower cervical vertebrae,biomechanical attribute of lower cervical vertebrae via finite element analysis,different approach for clinical affairs of cervical spine.Methods:(1)5 anatomical lower cervical model soaked by formalin were concluded,the model were scanned by CT machines.DICOM format were stored in a mobile storage device for further research.Then actural measurement,CT measurement and three dimentional measurement were used to qualify some cervical parameters and to ensure the relationship between above measurement.(2)For verify the model is effective or not,lower cervical vertabrea finite element model were constructed.Normal load were supplied to cervical spine in biomechanical research,lexion angle and deflection angle and axial rotation angle were compared to classical model.Then four internal fixation finite model(Magerl,Roy-Camille,Anderson and Ann)were evaluated under different scenario.Some parameter like stress map,maximum mises stress and average mises stress were evaluated.(3)Patients with different approach were compared,some clinical parameter like operative time,intro operative blood loss,etc were evaluated.Result:(1)A total of 25 cervical vertabrea were concluded in this research.Three methods of measurement including actural,three dimensional and CT methods were used in evaluating anatomical parameter.There is no significant difference between three methods(P>0.05).The maximum value in pedicle height,medial height,pedicle lateral pedicle diameter and pedicle diameter was C7 and minimum value always exsited in C3 and C4.(2)Effectiveness mainly through physiological cervical motion under different action.Lexion angle and deflection angle and axial rotation angle in this research consistent with classical paper results.On the basis of validated FEA model,some parameter including lexion angle and deflection angle and axial rotation angle in four finite element model(Magerl,Roy-Camille,Anderson and Ann)were evaluated.There is no significant concentrated stress in each posture.The sequence of stress concentration was Magerl,Roy-Camille,Anderson and Ann.Connecting rod screw stress concentration phenomenon is more apparent.(3)There is no siginicant difference between three group in Cobb angle and D value.All the parameter in patients improved obviously.There is significant difference between three groups in operative time,intro-operative blood loss.But,there is no significant difference between three groups in the JOA,ASIA score and complication rate.Conclusion:(1)Anotomical parameter in Europe-America really have bigger difference.At the same time,anatomical parameter in different gender seems sifnificant.Design is based on gender difference in Chinese internal fixation devices is imminent.(2)Magerl fixation in deflection resistance,resistance to rotation and pull-out output has obvious advantages.Magerl fixation has high safety in the operation and mechanical performance,is worth clinical popularizing widely.(3)All the surgical approach can meet the basic needs of the patients with cervical spine injury.