Melting down hips and knees: The afterlife of implants

As people live longer and medical technology improves, more and more of us will have a surgical implant before we die. We are also getting cremated in larger numbers - and so there is often some expensive metal left among the ashes. Where does it go?

"You tell people what you do, and they think... well, that's a bit strange," says Ruud Verberne above the din of giant sorting machines twirling and clanking.

Verberne is co-founder of OrthoMetals, which recycles metal implants from cremated human bodies. That's everything from steel pins to titanium hips and cobalt-chrome knees.

These are the knees that we have to recover," he says. "Some metals can be sorted by magnets. And the remaining have to be sorted by hand."