Finite element analysis of the Union Plate in treating elderly acetabular fracture patients

Abstract

Background Elderly acetabular fractures are one of the more difficult types of fractures to resolve. For patients at this age, the more common type of fracture is comminuted. How to better fix this type of fracture has always been an issue of concern. This study was performed to observe the mechanical properties of different internal fixation methods used in treating elderly acetabular fracture patients. Methods A model of a comminuted acetabular fracture in osteoporosis was established, consisting of an anterior column–posterior hemitransverse fracture with disruption of the quadrilateral surface. Fixation of the acetabular fracture model using a reconstruction plate and Union Plates was simulated. For the different internal fixation methods, static and transient modal analyses were performed under different loads, with an action time of 0.21 s and an analysis time of 0.7 s. The stress of the model was observed in the static analysis, and the displacement of the nodes and the entire model in the U1 direction was observed in the transient modal analysis. Results In the static analysis, the stress of the osteoporosis model, the suprapectineal pelvic reconstruction plate model, the infrapectineal quadrilateral surface buttress plate model, and the suprapectineal quadrilateral surface buttress plate model were 42.62 MPa, 37.49 MPa, 44.39 MPa, and 46.15 MPa, respectively. The stress was mainly distributed near the suprapubic branch. The corresponding displacement in the U1 direction was 0.1500 mm, 0.1020 mm, 0.0836 mm, and 0.0990 mm, respectively. In the transient modal analysis, there was a significant difference in displacement between the different models (P < 0.05). When different loads were applied with the same fixation method, there was no significant difference in model displacement (P > 0.05). Conclusion Static and transient modal analyses show that the infrapectineal quadrilateral surface buttress plate or the suprapectineal quadrilateral surface buttress plate has an advantage in maintaining the stability of fracture fragments when fixing comminuted acetabular fractures in elderly individuals. The infrapectineal quadrilateral surface buttress plate also presents better biomechanical results.

Third-Generation Dynamic Anterior Plate-Screw System for Quadrilateral Fractures: Digital Design Based on 834 Pelvic Measurements

“…Previous studies have found that the application of 3D printing technology could significantly reduce the amount of intra-operative bleeding and operative time [ 27 ]. In finite element analysis, Mimics is also an important software to create 3D reconstruction pelvic model for further study of biomechanical stability under different internal fixation methods [ 28 , 29 , 30 ].…”

Finite element analysis of posterior acetabular column plate and posterior acetabular wall prostheses in treating posterior acetabular fractures

“…The plates, screws and prostheses in this study were all assigned the properties of titanium alloy, with a Young modulus of 110 GPa and Poisson ratio of 0.316 [ 8 ]. It was assumed that the materials of the internal fixators, prostheses and ilium were all isotropic.…”

“…It was assumed that the materials of the internal fixators, prostheses and ilium were all isotropic. When assigning material properties to the iliac bone model, we followed our previous method [ 8 ], based on the CT value. According to the formula, different CT values correspond to different Young’s moduli; thus, the true material properties of the ilium can be approximated.…”

“…According to the formula, different CT values correspond to different Young’s moduli; thus, the true material properties of the ilium can be approximated. In the static analysis, surface‒surface contact, hard contact tangent behaviour, a penalty contact attribute and a friction coefficient between bone and bone of 0.40 were applied [ 8 ]; surface‒surface contact, hard contact tangent behaviour, a penalty contact property and a friction coefficient between the internal fixators or prostheses and the ilium of 0.45 were applied [ 8 ]. As boundary conditions, the pubic symphysis, articular surface of the ilium and sacroiliac joint were fixed.…”

Finite element analysis of titanium anatomic plate and titanium reconstructive plate for treatment of extra-articular fractures of the scapula

“…According to the gray scale of CT, cortical bone and cancellous bone were distinguished so as to set different material parameters. The elastic modulus and Poisson’s ratio of various structural materials are shown in Table 2 [ 10 – 12 ].…”