Visulization Of Human Cervical Spine Manipulation And Safety Research Based On Finite Elements Analysis

Cervical rotatory manipulation is an effective treatment for some neck diseases,however,its mechanism is still controversial,and furthermore,its domestic basic research is poor. Based on the groundwork of the manipulation,in this study,the cervical spine was visualized so as to explore the mechanism of the cervical rotatory manipulation and improve its accuracy and safety in the treatment. In addition,the research system of the visualization was established and the finite elements of the cervical mechanics were analyzed for a new attempt to study the stress of the cervical spine.The present study consists of two parts. The first part is to visualize the cervical spine with the computer aid. The three-dimensional (3D) motions of the spine were shown by means of body display methods and the obtained reconstruction images could be measured precisely. The cadavers specimens were scanned serially by the slice distance of 2mm with computed tomography (CT),next,the data of CT images were input and processed in the computer,and then the 3D images of the cervical spine were reconstructed and the transversal diameters of the spine canals were measured. It was found out that the 3D reconstruction model of the cervical spine accorded with the structure of the real cadaver specimen by comparing their respective measurement results. Therefore,the visualization system indicates a new way to study rotatory manipulation. With the computer,the "blind" and "subjective" manipulation can be simulated and reproduced,and its mechanism can be revealed by the trans-disciplinary researches.The second part aims to investigate a new method to analyze the cervical rotatory manipulation safety by the finite elements analysis of the odontoid process,since nowadays,there is few basic researches on biomechanics and quite a lot miscarriages take place when the cervical rotatory manipulation is applied in the clinic. In this part,the scanning was made along the cross section by the slice distance of 1mm with spiral CT. Next;the CT images were input and processed in the computer. And then the geometric model was established. The odontoid vertebra space in the model was divided into lattices and the stress area of the odontoid vertebra was identified by force loading and analyses. It was found that the structure of the stress concentration area was closely related to the development of split sections. Therefore,when the odontoid process is attacked by the external force along its vertical plane,its waist is likely to break and type II fracture occurs. And the break also possibly appears in its base,in this way,type HI fracture occurs. It is believed that the present research will help to avoid the clinical miscarriages in the future.