"When this is inserted into the bone, bone sees bone, and it grows into the device. And that's how the fixation occurs" Doctor Thomas P. Sculco, Surgeon-in-Chief at the Hospital for Special Surgery in New York, explains the nature of the hip prosthesis and its materials in this first segment.

Dr. Scuclo:

This has been in a drawer bouncing around for probably 6 or 7 years. And you can still see the surface of this ceramic is still pristine.



There's been an evolution in terms of the way we do hip replacement because we've been doing it now 30 years, almost 40 years. The evolution has been in the design of the materials that we affix the implant to bone. Initially we used metal and plastic articulations, and then we spent a lot of time looking at other surfaces to reduce the wear. Because you move you're hip a million and a half cycles a year. So any two surfaces you put into contact a million an half cycles a year is gonna wear. This for example is a hip replacement of a more current design. This is made of solid titanium. And it has flutes on it here which help with fixation into the bone. But more importantly it has a covering in this upper part here. Something called hydroxy appetite, which is what bone is made of. So basically when this is inserted into the bone, bone sees bone and grows into the device. And that's how the fixation occurs Now the other thing you'll notice here is the ball, and the ball in this case is ceramic. So this is a very very dense ceramic. This has been in a drawer bouncing around for probably 6 or 7 years. And you can still see the surface of this ceramic is still pristine.