Finite Element Analysis Of Different Percutaneous Fixation Strategies Used For The Treatment Of Tile C1.2 Pelvic Fracture

Objectives:INFIX technology is one of the main minimally invasive treatment methods for pelvic fractures.At present,this technology has been improved in clinical practice,but its biomechanical differences have not been fully verified.This paper mainly uses three-dimensional finite element model of pelvis to study and compare the biomechanical effects of different combinations of INFIX technology in the treatment of TileC1.2 pelvic fractures.Methods :Using a computer using 3D finite element method,set up a side of sacroiliac joint dislocation and the pubic bone fracture unstable pelvic fractures(Tile C1.2 type),fixed method of simulation of nine different combinations of INFIX technology,and in the vertical direction and the direction of rotation to give the pelvis model 500 N load,comparing with different combinations of INFIX fixed method after treatment of pelvic stress and displacement of all related.Results: Vertical direction and external rotation direction after loading each part of the pelvis model 500 N load stress comparison: pure INFIX fixed,whole pelvic stress has no obvious improvement,and no obvious difference between different combinations of INFIX combinations,simple overall stress sacroiliac screw fixation after pelvic down significantly,with INFIX fixed pelvic overall stress at a further decline.The stress of the sacroiliac joint also decreased to a certain extent under the condition of simple INFIX fixation,but the improvement was obvious without the condition of simple INFIX fixation,and the decrease trend of stress was greater when the fixation was combined with different combinations of INFIX.With pubis fracture a maximum stress under the pure INFIX fixed the blank group also has the obvious difference,even better than pure sacroiliac screw fixation after pelvic ring effect is remarkable,but with different combinations of sacroiliac screw works best when INFIX,and sacroiliac screw + 4 nail fixed its minimum maximum stress,but compared with sacroiliac screw nail fixed + 3,3 pin,the healthy side effect is better than nailing with side nailing.Comparison of the displacement of each part of the pelvis model after 500 N loading in the vertical direction and the external rotation direction: when the pelvis model was fixed with different combinations of INFIX alone,the overall displacement,vertical displacement and horizontal displacement of the whole pelvis,the left sacroiliac joint and the pubic ramus fracture were all decreased compared with the blank group.The displacement of the whole pelvis,the sacroiliac joint and the pubic ramus fractures in all directions were also significantly improved with the sacroiliac screw fixation alone,and the decrease of displacement with the sacroiliac screw fixation combined with INFIX was not significantly compared with that with the sacroiliac screw fixation alone.Among the different combinations of fixation,the sacroiliac screw +4 screw fixation had the smallest displacement,but it was not obvious compared with the sacroiliac screw +3 screw fixation.Among the 3 screws,the displacement reduction effect of the screw placement on the healthy side was still better than that of the screw placement on the affected side.Conclusion : In the type Tile C1.2 pelvic fractures treatment,pure INFIX of sacroiliac joint dislocation and fracture also have improved,but the ring stable effect is not obvious,when cooperate with sacroiliac screw biomechanics better overall performance,before and after pelvic ring can effectively stabilize,and sacroiliac screw + 4 nail fixed the most stable,but compared with sacroiliac screw nail fixed + 3 is not obvious,comparison between 3 nails,the contralateral nailing is better than with lateral nailing.