Development of Surrogate Model for Patient-Specific Lattice-Structured Hip Implant Design via Finite Element Analysis

Abstract

Patient-tailored hip implants are a major area of development in orthopedic surgery. Thanks to the recent developments in titanium printing, the medical industry now places special demands on implants. The lattice design enhances osseointegration and brings the stiffness of the implant closer to that of the bone, so this is an important direction in the development of hip implant design processes. In our previous research, several lattice structures were compared from a strength perspective, considering surgical specifications regarding cell size. The so-called 3D lattice infill type built into ANSYS with a predefined size has proven to be suitable for medical practice and can be easily manufactured with additive manufacturing techniques. A major step in the implant design process is numerical strength analysis, which elucidates implant material response. Due to the complex geometry of the lattice structure, finite element calculations are extremely time-consuming and require high computation capacity; therefore, the focus of our current research was to develop a surrogate numerical model that provides sufficiently fast and accurate information about the behavior of the designed structure. The developed surrogate model reduces the simulation time by more than one hundred times, and the accuracy of the calculation is more than satisfactory for engineering practice. The deviation from the original model is, on average, below 5%, taking deformation into account. This makes the design phase much more manageable and competitive.

Keywords

• lattice structures
• finite element analysis
• hip implant
• surrogate model