Knee implant survival check: will new plastic design outperform the old?

This study will follow 78 people aged 50 to 85 who need a total knee replacement to see how well a newer all-polyethylene (plastic) knee implant holds up over 5 years. Researchers want to know if this design, which may be cheaper and have fewer mechanical problems, works as well as or better than standard metal-backed implants. The main goal is to track how many implants fail and need to be replaced.