Brooks v. MacDonald: Why Cut Off Your Head? Resurface It Instead
OTW Staff • Thu, January 18th, 2018
This week’s Orthopaedic Crossfire® debate was part of the Annual Current Concepts in Joint Replacement® (CCJR), Winter meeting, which took place in Orlando. This week’s topic is “Why Cut Off Your Head? Resurface It Instead.” For is Peter J. Brooks, M.D., F.R.C.S.(C), Cleveland Clinic, Cleveland, Ohio. Opposing is Steven J. MacDonald, M.D., F.R.C.S.(C), University of Western Ontario, London, Ontario, Canada. Moderating is Clive P. Duncan, M.D., F.R.C.S.(C), University of British Columbia, Vancouver, British Columbia, Canada.
Dr. Brooks: I’m primarily going to be mentioning the BHR—the Birmingham Hip Resurfacing system—but this applies to some other designs as well.
The difference between resurfacing and total hip replacement is the difference between putting on a hat and cutting off your head. But it’s not a procedure you should think of as competing with total hip replacement. Keep that in mind.
Resurfacing complements total hip replacement in a small subset of patients now—the young, active male with osteoarthritis. Also keep in mind that metal-on-metal total hip replacement is a very different problem. Most of those were associated with trunnionosis problems because of the large head exerting excessive torque on the small Morse taper.
And Clive, your group published on that some years ago.
Steve is going to show you data which compares hip replacement to resurfacing in a global sense. And yes, there is a 37% higher failure rate in the latest Australian joint registry, if you do resurfacing. But that misses the point. The registry data is at a 30,000-foot overview of all patients, of all ages, genders, sizes and diagnosis with multiple brands of resurfacing devices, some of which are failing at 30%, and have been recalled, and surgeons in all levels of experience and volume at different centers around Australia.
But we’ve learned, and it’s been a long time coming, that there is a small best cohort for resurfacing, which are the young, active males with osteoarthritis. Additionally, it’s important to use an implant with a good track record and preferably do the surgery in a high-volume center because these are difficult procedures.
So, let’s say you look at the very same registry data and you granularize it down. You have only two resurfacing devices being done in Australia now—the BHR and the Adept, which are very similar in many ways, including metallurgy. And they have a one-third lower failure rate in males under 55 at 10 years, than do the total hips, and that’s excluding metal-on-metal total hips, which is appropriate since they’re not done any more.
So now it’s a lower failure rate in this small, select group of young men. And if you’re a young man under 55—and I see these people—they don’t care that it’s equal or better. They’d be happy if it was almost as good because they know that it saves a lot of their bone. It allows them to return to their full activity and that includes sports and even professional competitive sports. Better revision options in most cases in the future. And they’re young.
Resurfacing certainly saves a lot of bone on the day of surgery and it goes on saving bone in the upper femur because there’s no stress shielding. The loading biomechanically is much more normal. Dislocations and leg length problems are quite rare. And remember that these two problems are some of the most common complaints of total hip replacement.
In 2013 independent researchers from Oxford and Southampton (Carr et al., BMJ) looked up the data from the UK hospital episode statistics database. Almost 400,000 total hip replacements compared with 18,000 resurfacings reached the conclusion—reduced long-term mortality with hip resurfacing—compared to patients receiving other types of hip replacement.
Similar findings in the Australian Registry—not as well analyzed with the multi-variate, just age and gender—but showing at 15 years a higher mortality in the total hip group. And by the way, we’re finding the same thing in our series at the Cleveland Clinic—lower mortality when compared with total hip replacement. Those were age-matched patients under 55.
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.
I’m sorry, but resurfacing is the worst compromised head-neck ratio there is. I don’t understand the argument that it has improved range of motion. And probably the biggest fallacy is this proposed advantage of greater activity level and return to sports. I mean, it’s anecdotal and unproven. It’s hype over science. Quite frankly there’s massive patient selection and bias in the whole thing, and there’s not one blinded, randomized trial to show that.
Try to do resurfacing in a young, bulky male—it’s very difficult with that femoral head in place. As you can imagine, there are challenges with restoration of leg length if it’s short.
So, try if you can to avoid those patients. Avoid the patients that are osteopenic. Beware of the temptation of all women. That’s professionally speaking because, quite frankly, resurfacings have atrocious results in all women. If you’re a woman less than 40 when you have it, a 13% rate of revision has been reported.
Peter doesn’t do women and there is good reason for that.
Here’s Peter’s argument. ‘I’m only going to do a resurfacing in young males.’
All right. Let’s go through that. The data now debunks that.
The Australian Registry. The revision rate of males who have a total hip or resurfacing at 55 years of age, follow them for 10 years, a total hip is 5.4% and resurfacing—and that’s excluding the ones that have been recalled—is 6.7%. It is not lower in young males. That’s fallacy.
The Finnish Hip Registry demonstrated not a single hip resurfacing met our guidelines of a less than 5% revision rate at 10 years. Multiple hip systems do. And what’s not talked about is when a resurfacing fails, and you must do a revision, at Oxford the 10-year re-revision rate is 38%. In the Australian Registry, the 10-year re-revision rate, so once you’ve done the revision, 26% return for another revision.
In terms of cost, a resurfacing implant will cost most institutions significantly more than any alternate bearing, and that’s never discussed.
So truly, in my opinion, there is not a single reason to be performing resurfacings, except for one. The most compelling reason for resurfacing that I ever heard was from a good friend of mine who said, “Some patients have an emotional attachment to their proximal femoral bone.” I say, treat that with psychotherapy not with surgery.
Moderator Duncan: Excellent debate. Peter, I have a question for you. In the cases that are ideally aligned, we cannot recognize any edge loading, we are still seeing, it’s uncommon, cases of adverse local tissue reaction. Can you explain it in the male patient?
Dr. Brooks: Well, I can’t fully explain it, but there are some reports, for instance, of pseudo-tumors associated with the BHR that only looked at acetabular inclination. And one of the harder things to measure is acetabular anteversion. It’s like getting an X-ray of a fracture. If you need an A-P and a lateral it could look great in one and not in the other. And that’s been my problem when I’ve had adverse local tissue reactions. It hasn’t been due to inclination, it’s been due to anteversion and the way certain pelvises are more tipped back, which tends to edge load the anterior rim. There was a study out of England that looked, in coded form, at failures of resurfacing and wear properties and whether they were infected, fractured, dislocations or pseudo-tumors, the analyzers didn’t know. When they broke the code, all the pseudotumor patients had edge loading…all of them.
Moderator Duncan: Steve, if we were to change the materials successfully—not metal-on-metal any more, metal on something else such as poly or ceramic-on-ceramic—would you change your mind? Would there be a group of individuals you feel this would be suitable for?
Dr. MacDonald: No.
Moderator Duncan: Give us your thoughts, on surveillance after a patient has had one of these and he or she is quite happy with it. What surveillance do you follow at your institution Peter?
Dr. Brooks: I’m doing clinical visits at 1, 2, 5 and 10 years. Then I’ll be done.
Moderator Duncan: The question of ions and other things come up?
Dr. Brooks: We get ions and we get 3-dimensional imaging with MARS MRI in symptomatic patients.
Moderator Duncan: My last question for each of you, the patient has had one side done, is happy, wants to have the other side done. Do you feel compelled to get the ions and to get screening of the first side to see if the process is already underway? This patient has become sensitized to cobalt.
Dr. Brooks: I always get ion levels if I’m about to do the second side. More to be aware of it so that if there’s trouble 5 years later I know which side was the trouble maker.
Dr. MacDonald: I think that’s a good idea to get a baseline, a midline on the first side.
Moderator Duncan: We’ve come to the end of the discussion. Join me in thanking the debaters.
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