Improved Performance of Polymethyl Methacrylate for Minimally Invasive Orthopedic Implants

Polymethylmethacrylate (PMMA) based polymers are commonly used in orthopedic implant applications, and have been a successful cement for many decades. Recent implant designs use PMMA as a structural material, and additional applications are envisioned, but only if improvements in the PMMA mechanical properties, especially fatigue performance, can be attained. This paper presents a number of strategies for improving the performance of PMMA as an orthopedic structural polymer, including modification of the polymer chemistry, incorporation of acrylic reinforcement and the use of metal braids as reinforcement of a specimen exterior. Experimentally measured properties of the material are presented. Results include up to 100% increase in cycles to failure compared to commercially available medical grade PMMA through chemistry modifications, up to 800% increases due to fiber reinforcement, and further significant improvements due to metal braid reinforcement.