Researchers in Malaysia, Iran and the UK have designed a new biomaterial that could significantly extend the life span of total knee replacements by addressing the most common cause of their failure.

Led by Marjan Bahraminasab of Universiti Putra Malaysia, the researchers used computer modelling and structural analysis to help

Aseptic loosening is most challenging in the femoral component of a knee implant because it interfaces with all of the other components of a knee prosthesis. Image:

design a metal-ceramic, porous biomaterial that would replace the cobalt-chromium metal alloy normally used in knee implants. The team’s goal was to reduce the risk of aseptic loosening: a failure of the bond between a knee implant and bone tissue.

In a paper published in Materials and Design, the team reported that their functionally graded biomaterial (FGBM) would improve the performance of total knee replacements. It would do this by addressing the three leading causes of long-term failure: stress-shielding of the bone by the implant, wear of the articular surfaces, and the development of soft tissue due to motion between the bone and implant.

For the FGBM to be fully effective, the shape of the femoral component, particularly the interface geometry, should be modified in order to optimise the design, state the authors. “This will need to be done in consultation with an orthopaedic surgeon in order to better understand the practical limitations of surgery and avoid weakening of the femur.”

Various animal tests and in vitro experiments are required before using the new biomaterial in human trials. “After obtaining acceptable results, our research will focus on optimising the material processing aspects to ensure cost effective manufacture of the implant,” says Bahraminasab.



For further information contact:

Marjan Bahraminasab
Department of Mechanical and Manufacturing Engineering
Faculty of Engineering
Universiti Putra Malaysia