The Measurement Of Digital Clinic Anatomy, Personalized Surgical Planning And Finite Element Analysis Of Pedicle Rib Unit For Fixation Of The Adolescent Idiopathic Scoliosis

The adolescent idiopathic scoliosis is difficult to treat，It is veryimportant to use the posterior pedicle screw fixation system，although theadolescent’pedicle are narrow and complex，so the operation of it is mostdifficult than others. The pedicle rib unit fixation was good methods tosolve this questions，But the basic study to support this method wasrareless.PART ONEObjeetive：To observe the structure and measurement the clinicanatomical paremter of pedilcle rib unit.Methods：we chosed6cadavericsof the department of anatomy，Inner Mongolia Medical University，weretained the thoracic verterbra，verterbra disc and rib，we measured thefollows paremters the width，the height，the pedicle screw length and thesagittal angles of the pedicle rib unit compared with pedicle，especially forthe pedicle-rib overlap height.Results：The measurement results of theabove-mentioned parameters were as follows:PRC-W:12.13-20.13mm， PRC-H:6.18-11.83mm，PRC-L:47.81-66.84mm，PRC-TA:12.47-41.33°，PRC-SA:72.67-86.28°.Conclusions：1The width，length of pedicle rib unitare larger than the parameter of pedicle，so the strength of pedicle ribunit is larger than pedicle fixation.2The greater inward angle is largerthan pedicle fixation，so the safe angle is larger than the other，it is decreasethe danger of the operation of fixation.3There is more difference betweenpeople on pedicle rib unit paramenter，so we should desigen differentoperation plan to different patient.PART TWOThe personality3-D digital operatin design and itsappliation.Objective：To study the methods of3-D digital operatin designon adolescent idiopathic scoliosis and the application value of it.Mehtods：We chose one adolescent idiopathic scoliosis patient，and CT scaned with1mm height，and we used Mimics10.01to3D simulate model，andmeasured the parameter of the PSA，screw length and width of screw，andapplied with this parameter in operation.Results： We reconstrution the3-D model of adolescent idiopathic scoliosis，and situated the position ofscrew and pedicle rib unit，and prevent the screw to penetrate the pedicleand verterbra body，desigened the plan of operation and applied，none ofscrew was penetrate the pedicle and verterbra body.Conclusion：Thedigitalized visualization adolescent idiopathic scoliosis could increase theachievement ratio. PART THREEThe finite element analysis of correction strategies for scoliosiscorrecfion.Objeetive：To reconstructed a3-D finite element model of AISand compare tthe validity of the model，which provides a basic model forcontinue study.Methods：we chosed a patient with AIS，and used CTscanning with thickness of1millimeter.We reconstruction the3-D modelsof AIS and FEA models of AIS.Results：The finite element model containseight vertebra， seven inter-vertebral discs and related subsidiarystructure.Using4mesh types and13kinds of material parameters，themodel consists of1351327nodes，1511549tetrahedron elements，1631320shell elements，56cable elements and42rod elements.This was far more than previous similar models.The model was moreaccurate not only on structure and material properties，but also on units ofconstruction，realistic appearance and geometric similarity.Conclusions：1.The model has high quality in precision and geometric similarity，andrelative biomechanical research Can be done on it.2.Relativebiomechanical and clinical analysis Can be easily conducted on the3-Dfinite element model of scoliosis.It is possible to analyze diversity of stresson different conditions.