Finite Element Analysis of Fully Threaded Versus Partinally Threaded Sacroiliac Screws in the Treatment of Tile C1.3 Pelvic Fractures
ZHANG Xiangdong
ZHANG Haifei
ZHANG Xin'an
YANG Dongsong
Abstract：Objective To compare the mechanical performance of fully threaded and partially threaded sacroiliac screws in the treatment of Tile C1.3 type pelvic fractures through finite element analysis,providing a theoretical reference for clinical fixation strategy selection.Methods Three groups of Tile C1.3-type pelvic fracture internal fixation models were established:group A(S1 and S2 fully threaded screws),group B(S1 partially threaded screw,S2 fully threaded screw),and group C(S1 and S2 partially threaded screws).Finite element analysis was performed to simulate standing still,standing with forward bending,and standing with left rotation,analyzing the total displacement and Von-Mises stress distribution of the fracture fragments and the internal fixation devices.Results Under three physiological conditions,the total deformation of the pelvis,sacral fracture fragment,and screws in group A was the lowest among the three groups,indicating the strongest posterior pelvic ring stability.Group C had the highest total deformation overall,showing the poorest stability.The total deformation in group B was between groups A and C,closer to group C.In terms of stress distribution,the peak equivalent stress of the pelvis,fracture fragment,and screws in group A was the lowest among the three groups,while group C had the highest peak equivalent stress.The peak equivalent stress in group B was significantly lower than in group C but slightly higher than in group A,showing no mechanical advantage.Under the forward bending posture,both the total deformation and equivalent stress indicators were highest in all three models.Conclusion Fully threaded sacroiliac screws are significantly better than partially threaded sacroiliac screws in controlling fracture end displacement,optimizing stress distribution,and reducing the risk of screw failure,making them a more ideal minimally invasive fixation option for treating Tile C1.3 type pelvic fractures.
Keywords：Tile C1.3 pelvic fracturefully threaded sacroiliac screwpartially threaded sacroiliac screwposterior pelvic ringbiomechanicsfinite element analysis
Publication Date：2026-08-13
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：8( 2707-2714 )