My total knee surgery has been postponed because the surgeon had to order a new replacement. He said the old one had been at the hospital too long. Is this a way to just increase the price by buying a new one when the one on hand would do just as well?

Actually, no. You can probably thank your surgeon for being so careful. A recent study from the Anderson Orthopaedic Research Institute has shown that implants with a longer shelf life are also linked with greater amounts of osteolysis.

Osteolysis is the bone loss that comes when bits of bone and debris from the implant flake off. Not only does this cause bone loss but it can also weaken the implant so that it can come loose. Osteolysis can also weaken the bone leading to fracture.

The risk of osteolysis increases by a factor of 1.5 for every year the insert stays on the shelf. It’s thought that the quality of the plastic components is less with time. This can contribute to implant failure and other complications.