What about the outcomes? They’re darned good. If you’re a male under 55 these four studies (McMinn, Treacy, Murray, Brooks) show 99% and 100% success rate at 10 to 15 years.
Pseudo-tumors—continuing worry. It’s been traced to edge loading which makes this a more technically demanding and riskier procedure say in women who are loose jointed, small size. Component malposition is critical, and these devices have complicated geometry. It’s not a simple 180-degree sphere. And the lateralization of the center of rotation robs you of coverage and is more likely to lead to edge loading, so cup positioning is different than hip replacement.
Some brands were more likely to lead to edge loading…and they’re gone.
Steve, I don’t know if you recognize the fellow in this picture. This is Dr. Emil Schemitsch who recently moved from Toronto to London where you work in Ontario. He took a job as chair of surgery, which makes him your boss. He’s also one of the most prolific resurfacers in Canada. He does BHRs and has petitioned the Ontario government this summer for more funding to be able to do even more.
I’d like to close with a picture of 100 patients, 55 of them are female. I’m not interested in resurfacing them. That leaves 45 males and I’m not even interested in resurfacing all of them. But there’s 8 of them out of the first 100—8 males under the age of 55 and if you replace their hips, you run the risk of them coming back in telling you that they are not entirely pleased with their hip replacement.
Dr. MacDonald: Well, Peter if you know me, you know no one’s my boss, actually. I’m on the con side, thankfully, the side with data.
So, hip resurfacing, I will concede, makes inherent sense, and has tremendous advantages if it’s 1995 when your choices are resurfacing, other hard-on-hard bearings, conventional polyethylene, but for heaven’s sake, are we still not sure about resurfacings? Who still believes it’s a good idea?
Well, I’ll tell you. Not many. Resurfacing peaked out at 8% 10 years ago as they follow their data, down to 0.8% in 2015. In the U.S. it peaked around 7-8 years ago. Currently in the U.S. 92% of the time highly cross-linked poly is used, resurfacing 0.5%– Peter is probably doing 0.4% of them.
So why the down trend? Well, they have a higher failure rate in every single patient population over total hip. They have not demonstrated a single credible advantage over total hip. And as a special bonus, they’re much more expensive than a total hip.
So, let’s go through some of the proposed advantages that Peter mentioned.
Bone preserving. Well, that’s sort of a yes and no. Sure, on the femoral side you don’t breach the canal, but not on the acetabular side.
The thing that I’m really not understanding is what do you do at 12, 14 years with a well-fixed component? Are you supposed to remove it? I know if I have a modular shell I can pop the poly and do a revision. I don’t know what I’m supposed to do with this monoblock shell. I don’t consider that, quite frankly, bone preserving.
And on the femoral side, for heaven’s sake, most of the implants were revised for the socket. You got a well-fixed femoral component. What problem is it solving? And lastly, what is not addressed is the issue of osteopenic fractures that can occur in the elderly. Maybe not the elderly men, but we still do see subcapital hip fractures. Is that really going to be zero?
You are using metal-on-metal technology, so let’s just face it. There’s multiple, multiple issues with that—soft tissue reactions, higher failure rates, monitoring and the complexities that go along with that.
