That's an interesting question. Thank you.
In the ideal world we would get to the point where we wouldn't have to do hip and knee replacements, where we can prevent the progression of arthritis. That would mean the early detection and treatment of osteoarthritis, and early detection and treatment of inflammatory arthritis, such as rheumatoid arthritis. If they get there, however, the ultimate goal would be to develop a hip or knee implant that patients are completely unaware of, that functions normally, and that lasts patients for the rest of their lives.
There are two main areas we look at now. In knee replacements—you may remember that data I showed you there—about 5% of knee replacement patients aren't happy with the result. It doesn't feel like a normal knee. It clicks and catches, and they have aches and pains. It's a bit unstable and doesn't feel like a normal knee. I think we have a lot of work to develop implants that feel more normal, particularly in knees. The other issue is longevity. These eventually wear out. I had some pictures showing broken implants and rod implants, so there's a lot of work being done right now to improve the bearing surface—that's what we call it—to improve longevity. We've made a lot of headway there.
The last issue that we have to deal with is the ongoing issue of infection. That is, infection at the time of the operation and even late infections five or ten years down the road. I think we'll be developing implants that help reduce the chance of infection. Those are the three main areas.