Finite element analysis of bone and implant stresses for customized 3D-printed orthopaedic implants in fracture fixation.

3D printing allows product customisation to be cost efficient. This presents opportunity for innovation. This study investigated the effects of two modifications to the locking compression plate (LCP), an established orthopaedic implant used for fracture fixation. The first was to fill unused screw holes over the fracture site. The second was to reduce the Young's modulus by changing the microarchitecture of the LCP. Both are easily customisable with 3D printing. Finite element (FE) models of a fractured human tibia fixed with 4.5/5.0 mm LCPs were created. FE simulations were conducted to examine stress distribution within the LCPs. Next, a material sweep was performed to examine the effects of lowering the Young's modulus of the LCPs. Results showed at a knee joint loading of 3× body weight, peak stress was lowered in the modified broad LCP at 390.0 MPa compared to 565.1 MPa in the original LCP. It also showed that the Young's modulus of material could be lowered to 50 GPa before the minimum principal stresses increased exponentially. These findings suggested the modifications could lead to improved performances of fracture fixation, and therefore likely that other orthopaedic implants survivorship could also be enhanced by customisation via 3D printing. Graphical abstract.