Moderator Thornhill: There’s also the concern of the landing zone where you have a certain target for a knee and some implants narrow the target zone. Do you think the medial pivot does that?
Dr. Nam: I don’t see that as being a big difference. I think that your surgical technique right up until the end of the surgery is essentially the same, whether you’re doing a medial pivot knee or whether you’re doing a cruciate retaining or an ultra-congruent knee. Does your surgical technique change when you do a medial pivot knee versus a cruciate retaining?
Dr. Walter: So, I think that that’s a very good question. Some aspects to a medial ball and socket knee narrow the landing strip. I’d say tibial rotation is one of those things and that’s because tibial rotation is not important if you’re using a rotating platform for example. When you have to get your tibial rotation right with a medial ball and socket knee or it won’t work, but there’s also some areas where the landing zone is wider and that is with the tension. I think you can afford to have it a little bit looser or a little bit tighter and it will still work. Whereas if you are using a cruciate retaining design, if it’s looser, the patient will be unhappy.
Moderator Thornhill: Okay good. So, Denis, Bill said that his results of his total knees are equivalent to his total hips and they’re both at 95%. Why do you think that Bill’s hips are equivalent to his knees?
Dr. Nam: Well that’s a great question, I mean maybe he’s a good surgeon who does a good knee replacement and gets those same results. I don’t see that, and I don’t know if any other surgeon in the U.S. that I’ve spoken to would report the same type of results in terms of satisfaction. I think the knee is inherently going to be a little bit more difficult to recover from, it’s a kinematically more complex joint. The knee is superficial, it’s right underneath the skin. It’s a longer recovery in my hands.
Moderator Thornhill: What do you think is the major reason only 80% of people are fully satisfied with their knee?
Dr. Walter: I think it’s because they don’t like an unstable knee. They don’t like a knee that slides forwards and backwards.
Dr. Nam: I think it’s patent expectations. I don’t think we educate our patients what to expect after surgery, after knee replacement. I think it’s hard to recover from it. I think we have to let them know that it’s not a normal knee especially in our younger patients, that we are not giving them a 20-year-old knee, so I think it’s completely patient expectations.
Moderator Thornhill: This was a great debate and I want to congratulate both of you.
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