RESUMO
Objective To analyze the relationship between pillow height and cervical intervertebral disc stress in lateral decubitus position of the human body using three-dimensional finite element method,and to provide the basis for appropriate pillow selection.Methods A cervical spine CT scan was performed on a normal male volunteer.The medical 3D image reconstruction software (Mimics),reverse engineering software (Geomagic Studio) and finite element software (MSC.Patran) were collectively used to establish three-dimensional finite element models of the whole cervical spine under three lateral decubitus conditions,includes pillow height of 10 cm (cervical spine leftward flexion),17 cm (cervical spine neutral),and 25 cm (cervical spine rightward flexion).Moreover,the finite element analysis and calculation of the three models were conducted.Results The Von-Mises stress,maximal principal stress and maximum shear stress of the model in cervical spine neutral (pillow height=17 cm) were all significantly lower than those of the cervical spine lateral model.Conclusions When the cervical coronal plane is in neutral position,the cervical discs can achieve the best stress distribution state.In lateral decubitus position of the human body,a appropriate pillow height should make the cervical vertebrae in neutral position.