What is the popping i hear after knee replacement surgery?

Metal on Plastic: The knee prosthesis we use to resurface or replace your joint is made of metal and plastic. When the two pieces contact each other it is not uncommon to notice a pop or click. There are other far less common reasons too, like instability, where the knee is loose.

Normal: As it is a man-made device, it is not unusual to hear/feel painless clicking in your knee after a successful knee replacement. If concerned, have your surgeon re-evaluate your knee.