Biomechanical evaluation of fracture construct for fracture fixation of the tibia

Abstract

Plate osteosynthesis is one of the methods that can be used by surgeons to treat patients with bone fractures and irregularities. There are various osteosynthesis plates available commercially, but the most suitable implant with optimum screw configurations is highly subjective and remained a topic of debate. The aim of the study is to determine the optimum implant-screws configuration and implant designs which could maintain stability of the construct during bone healing. The tibia bone was chosen for the analyses, and has been divided into three stages – the proximal, diaphyseal and distal part of the bone. Three-dimensional (3D) bone model was reconstructed from computed-tomography (CT) datasets, and the implant models were designed using computer-aided design software. Tibial fractures and deformities were simulated with reference to the orthopaedic literatures. Finite element analysis (FEA) was used with a common loading applied at the proximal tibia. Results showed that the use of Locking Compression Plate (LCP) for fracture fixation provides better stability to the construct despite having a large stress magnitude of 45.5 MPa (p-value<0.001). In terms of screws configurations, placement near the fractured site provides a more rigid fixation. In contrast, placing the screws further away from the fractured site gives flexibility to the fracture construct which may result in callus formation. For the pylon fracture, the Medial Distal Tibial (MDT) plate significantly reduced the displacement and stress magnitudes as compared to the Anterolateral (ATL) plate (p-value<0.001).