Electronic Thesis and Dissertation Repository


Master of Engineering Science


Biomedical Engineering


Dr. James Johnson

2nd Supervisor

Dr. Andrew Hrymak

Joint Supervisor


Hemiarthroplasty procedures replace the diseased side of the joint with an implant to maximize bone preservation while maintaining more native anatomy than a total joint replacement. Even though hemiarthroplasty procedures have been clinically successful, they cause progressive cartilage damage over time due to the use of relatively stiff metallic implant materials. This work investigates the role of low moduli implant material on implant-cartilage contact mechanics and early in vitro cartilage wear. A finite element simulation was developed to assess the effect of low moduli implants in the range of 0.015-0.288 GPa on contact mechanics. Higher contact area and lower peak contact stress was quantified as the Young’s moduli decreased. Bionate implants were fabricated through microinjection moulding for three Young’s moduli of 0.020 GPa, 0.035 GPa and 0.222 GPa. An in vitro wear study was conducted using a pin-on-plate simulator to investigate the effect of these different Bionate formulations on cartilage wear. A significant decrease in cartilage wear was observed for the 0.020 GPa and 0.035 GPa Bionate implants (p<0.001). In conclusion, these studies have demonstrated the desirable range of hemiarthroplasty implant moduli to reduce cartilage wear, and have shown that Bionate implants have the potential to provide improved longterm outcomes of joint hemiarthroplasty.

Included in

Biomaterials Commons