Observation Of stress distribution On a 3D wrist model after scaphoid fracture

Abstract

Scaphoid bone fractures are very often among carpus fractures. However, sacphoid fractures are diagnozed tardily. So, this lateness changes the treatment prognosis. Kirschner wires are mostly preffered because of its easiness of use as scaphoid fracture detection materials. Aim of this study is analyzing the stress distrubution of wrist and the change of total deformation before and after scaphoid fractures and also after the application of Kirschner wire. Segmentation process was done on CT images of wrist and 3D “stl” model was obtained and converted to solid model and finite element analysis were performed to realise this study. Metacarpal, carpaş, radius and ulna bones were linked as linear arc before the analysis. Afterwards, total stress distrubution and deformation were analyzed according to applied forces on metacarpal bones of fixed radius and ulna bones. By regarding the finite element analysis results, von-Misses stress distrubution were found 240,62 MPa before scaphoid fracture, 338,27 MPa after scaphoid fracture and 2678,1 MPa with after Kirschner wire application. Consequently, stress accumulation were observed on both scaphoid bone and Kirschner wire after scaphoid fracture. After this study, different fixation methods should be compared under same boundry conditions and then the most suitable fixation method may be determined. Moreover, it is encouraging that the most suitable personel implant designs may be done by using engineering approaches mentioned in this study.