3D finite elemental analysis on treatment of sacral fractures with different internal fixation implants

To provide the doctors a basis for treating sacral fractures and offer optimal surgical program, three-dimensional(3D) finite element method was used to simulate normal pelvis and the unstable pelvis suffered I section, U section and III section sacral fracture respectively.The unstable pelvises were respectively fixed with five different internal fixation implants types, which are respectively rectangular plate with cannulated screw, rectangular plate with solid screw, expansile bolt, convex plate with cannulated screw, convex plate with solid screw. The stress distribution and the X, Y, Z direction displacement of the sacrum were calculated for each sacral fracture treatment of five internal fixation implants after giving 500N axial load on lumbar vertebra and were compared with the normal pelvis, then the optimal surgery program were determined. After the analysis, by comparing the five combinations for each sacral fracture treatment of five internal fixation implants, the preferred combinations for the reset treatment of the I section sacral fractures were rectangular plate with cannulated screw and convex plate with cannulated screw; The preferred combination for the reset treatment of the la section sacral fractures was expansile bolt; The preferred combination for the reset treatment of the III section sacral fractures was convex plate with cannulated screw.