Simulations Improve the Life of Hip Replacements

A recent study involving simulations of hip prosthetics shows how CAE software can assist with the in-vivo behaviour of medical devices. As more youth, especially athletes, require hip replacements and as patient life expectancies increase, these prosthetics need to last longer. Simulation can hold the key to ensure that hip prosthetics will continue to work later in life.

The challenge of ensuring long lasting hip prosthetics affects manufacturing engineers and surgeons alike. Manufacturers, like Science et Médecine (SEM), use ESI’s CAE simulation software to digitally test new prosthesis material (from ceramics to metal alloys) and performance (including wear, noise, and vibration).

“Numerical simulation is commonly used by SEM to achieve reliable design and ensure the safe use of our medical devices", said Mr. Bréard, Research & Development Director at SEM. “We are very sensitive to software improvements, especially those incorporating dynamic simulation.”

He added, “The study conducted in partnership with ESI has improved our understanding of the mechanical behavior of our prostheses, for each tested design. The recent developments of simulation tools help us in increasing the reliability of medical devices including those requiring assemblies.”

For surgeons, however, their simulations can focus on the micro separation of the prosthetics’ femoral head and the cavity it occupies, known as the cup. With continuous use, this distance can cause micro impacts accelerating the wear of the device.

CAE Simulations of Extreme Loads on Hip Prosthetics

The series of studies included simulations of the prosthesis kinematics and stresses when under extreme accidental loads. The geometry and materials were modeled using ESI’s CAE platform Visual-Environment.

ESI’s Virtual Performance Solution was used to simulate the impact of nine kilonewtons in nine milliseconds. Similar loads would be seen if a patient were to fall down from a significant height, like a flight of stairs. The results accurately predicted contact areas and separation of the femoral head to the cup.

SEM, however, conducted another study to compare three designs created from a vanadium alloy. The goal was to optimize the prosthesis’ resistance to the same accidental loads. By simulating the fitting process, SEM could determine the prosthesis’ positioning and structural damage in an accident.

Benefits of FEA and CFD Simulations in the Medical Industry

“ESI has already proven its value in helping companies in the automotive, aerospace, energy and electronics domains. Now many other industries are turning to Virtual Prototyping as they see the benefits of being able to pre-certify products and anticipate product issues,” said Fouad El-Khaldi, Industrial Strategy & Innovation Director at ESI. “Obviously, the health sector represents a huge potential market because simulation can solve customization issues and help manufacturers deliver the best solution for each and every patient in less time and at an affordable cost.”

El-Khaldi has a point, with the aging population and longer life expectancies, the medical industry is certainly a growing field. By tapping into this industry, simulation companies will find many opportunities of growth from prosthetics, in vivo mass transfer of medications, medical scanners and more.

However, more specific biological processes are difficult to predict or simulate due to their individual and often unpredictable nature. That hasn’t stopped companies like Dassault Systèmes from entering the market with BIOVIA, a CAE software aimed at predicting biological, chemical and material systems. Or ANSYS’ use of CFD software to simulate the human circulatory system to help plan individualized lifesaving surgeries for infants. But will we ever be able to fully simulate individual human bodies and/or biological process? Comment below.

Source ESI-Group.