A Novel Anatomical Self-locking Plate Fixation for Both-column Acetabular Fractures: - Finite Element Analysis

Abstract

Background: Both-column acetabular fractures often require multiple plates for fixation, and the risk of internal implant failure is high. The author designed a posterior anatomic self-locking plate (PASP) to avoid the shortcomings. The stability of PASP was compared with two popular reconstruction plate fixation methods, and the influence of sitting, turning right and left on implants were explored. Methods: PASP, double reconstruction plate (DRP), and cross reconstruction plate (CRP) were assembled on the finite element model of both-column fractures of the left acetabulum. A load of 600N and a torque of 8N·m were loaded on the S1 vertebral body to detect stress and displacement changes when sitting, turning right and left. Results: The peak stress and displacement of three types of fixation methods on the left both-column fractures under three types of movements were CRP > DRP > PASP. PASP has the minimal value when turning left. The maximum peak of stress and displacement of PASP are 313.5 MPa and 1.15 mm respectively when turning right. Conclusion: PASP can provide higher stability than two reconstruction plates for both-column acetabular fractures. The rational movement after posterior DRP and PASP fixation for acetabular fracture is to turn to the ipsilateral side, which can avoid implant failure.