@article{article_261132, title={The investigation of the behaviour of tıredness according to the location of pedicle screw placement by finite element method}, journal={Sakarya University Journal of Science}, volume={20}, pages={301–306}, year={2016}, DOI={10.16984/saufenbilder.31154}, author={Uğur, Levent}, keywords={biomechanics,finite element analysis,pedicle screws,spine}, abstract={<p> <strong>The most common pain in a human body usually occurs in the back part. The statistics show that many people experience pack pain in a period of their lives. Surgical intervention may be necessary to relieve the pain experienced during the treatment of the severe belly and back pain and to reload the spine’s natural range of motion. Pedicle screws are mainly used when treating various physical deformations in the spine. Yet, incorrectly positioning the screws because of the sophisticated structure of the spine creates extra pressure on the screws and this creates damage on them because of the material fatigue. It is aimed in this research, that to determine the fatigue events occurring in the screws while setting the pedicle screw in optimal position and angle during the spine surgery. A three dimensioned vertebra model was created by processing the raw data obtained from the computed tomography images. In the vertebra model the pedicle screws were inserted in 27° and 40° angles according to the sagittal axis. The three dimension solid models of the pedicle screws were designed with the Solidworks software by using the parametric values taken from the manufacturer catalogs, and the three dimension pedicle screw and vertebra models were mounted in the Solidworks software in two different angles. The loads pressing over the vertebra surface in the normal stance position were applied after transferring the created model into the finite elements based ANSYS software. The titanium characteristics of the Ti-6AL-4V taken from the literature as implanting tool and S-N graphic were added into the ANSYS software. The a average stress and fatigue behaviours of the pedicle screw according to different positions in the vertebra model were compared. At the end of the finite elements analysis, when the position of the pedicle screw was near the central axis of the vertebra, in the cortical rim area, the average stress was calculated as 554 and 518 MPa. The area found to have the shortest lifescale was the one near to the head of the screw, where the most amount of stress was calculated and therefore it was discovered that lifescale values varied according to the area of stress. The findings comply with the position were the screw breakage was occured as mentioned in the literature. A preliminary study was done with the aim of preventing the troubles to be faced after the operation of mounting the screw by the surgeons in this research. Thus it was discovered that the screw mounted closer to the sagittal axis functioned more and had longer lifespan, and therefore the risk of damage was the least. For this cause it is thought that for surgeons to mount the screws by taking the position and angles into consideration is a factor to affect the success of the operation. </strong> </p>}, number={2}, publisher={Sakarya University}