Hamilton v. Haddad: The Anterior Approach: Better, Faster, Cheaper
OTW Staff • Fri, August 25th, 2017
This week’s Orthopaedic Crossfire® debate was part of the 17th Annual Current Concepts in Joint Replacement® (CCJR), Spring meeting. This week’s topic is “The Anterior Approach: Better, Faster, Cheaper.” For the proposition is William G. Hamilton, M.D., Anderson Orthopaedic Research Institute, Alexandria, Virginia. Opposing is Fares S. Haddad, M.D., F.R.C.S., University College Hospital, London, United Kingdom. Moderating is Andrew J. Shimmin, M.B., F.R.A.C.S., Melbourne Orthopaedic Group, Melbourne, Australia.
Dr. Hamilton: So we know that the use of the anterior approach is growing. The proposed advantages are that it’s intermuscular, avoids violation of the abductor, has minimal detachment of posterior stabilizing structures and maybe a lower a dislocation rate, and because of the supine positioning it facilitates the use of fluoroscopy. It also preserves the structure known as the hip deltoid, the gluteus maximus and tensor fascia lata structure, which is a known stabilizer of the hip that the other approaches tend to violate.
For better or worse, there’s been a fair bit of internet and press attention with claims of fairly radical differences between the different approaches and some surgeons have felt some pressure to adopt the approach. We’ve seen articles in The Wall Street Journal, The New York Times, and The Washington Post saying that there are fairly remarkable differences.
But we know there is a learning curve.
When you combine this learning curve with the rapid transition of approaches, you see these problems like longer operative times, increased blood loss, fracture rate, and the introduction of fluoroscopy. All this can be problematic and I worry a bit about rapid implementation.
But the truth is, in life there are learning curves for everything that we do whether it’s learning a new surgical approach, or maybe trying to ride one of those hover boards that were popular last Christmas. You’ve got to assess them. Am I physically capable of doing it? Am I willing to practice and take it slow? Am I willing to make wise choices? Because if you fail to do that, catastrophic things can happen.
I consider it my responsibility as an advocate of the anterior approach to teach the proper implementation of the technique and to honestly report the results and complications. I truly believe it’s all about patient safety. When I see cases walk into my office, done by early anterior approach converters, I get somewhat nauseous.
What happens once you get through that learning curve and you reach steady state in your practice? A paper that came out of three centers, including my own, with four surgeons; over 5,000 anterior approach hips with a very low rate of femur fracture, infection, and a dislocation rate that rivals that of any published article (Journal of Arthroplasty, 2015).
And who doesn’t really have a significant learning curve? If you have the opportunity to train during your residency and fellowship and you had the chance to see this approach over time and learn it in a staggered manner, you really have a very different learning curve when you enter practice. When I looked at the first 24 fellows that we trained with the anterior approach who had equal exposure to the anterior and posterior approaches during their one-year fellowship with us, 96% are currently using the anterior approach as their primary approach in practice and they’re not seeing the learning curve struggles that I myself dealt with when I converted half way into my practice.
We talked about the supine positioning. It does make the use of fluoroscopy easy. I said that it’s not necessary to do, but it certainly can improve implant positioning.
It requires attention to detail to do this properly and it can actually cause malpositioning if not used right. When I looked at my own data and I looked at the cup positioning of my last 100 posterior approach hips and my first 100 anterior approach hips, the number of outliers with the anterior approach was half that of the posterior approach. When I looked at my second 100 anterior approach hips, it was even lower—96% of my cups were in the Lewinnek safe zone.
The big question everyone asks is: ‘Does it result in a better recovery?’
Let’s look at some of the head-to-head studies. Now, many of these are subject to biases, surgeon bias and examiner bias. One good meta-analysis (Journal of Arthroplasty, 2015), 17 studies over 2,300 patients, nine of those reported on short-term pain and function. Four of them favored the anterior approach; and in five there appeared to be no difference. None of them favored the posterior approach. The secondary outcomes—the anterior approach was favored in length of stay and a significantly lower rate of dislocation.
Another study, published in March 2016 (Hip International), was a systematic review of 64 studies reviewed by two independent examiners and their conclusion statement was that there is strong evidence for faster post-operative recovery and less need for an assisted device with the anterior approach.
When you look at four North American studies that have been done—prospective, randomized—and you look at the eight columns on pain and function, you can see in six of the eight the anterior approach was better and two of the eight, there was no difference.
So in my summary of looking at the literature, when compared to the posterior approach the anterior approach yields equivalent to better pain scores and improved short-term functional recovery, but it does appear to be equivalent by somewhere in the four to eight week timeframe. When compared to the lateral approach it may actually be longer.
The posterior approach was already a very successful surgery. I kind of liken it to this 2004 Lexus—one of the first cars that I owned; it was an excellent car, very reliable, it got me to work back and forth; there were very few service problems and I loved that car until I got this one. It took me a little while to learn. I had to figure out how to use the wipers; and it had heated and cooled seats and I had to hook my phone up to Bluetooth. But once I learned how to drive it, I found it was faster, more efficient, safer and certainly more comfortable and in no way was I going to go back to that 2004.
Mr. Haddad: My role is to oppose this motion because the anterior approach is neither better, faster, nor cheaper.
As we’ve heard, the approach is important. But the key message here should be ‘Is it the approach you use or is it how well you do it?’
But for the record I’m going to look at the same data and tell you the anterior approach is not better, faster, or cheaper. Ultimately the goal of surgical exposure is get you to do the operation properly, preserve the soft tissues and get a good functional outcome. But it needs to be something that everybody can do well and not just expert centers and the few people that they train.
We’ve been here before. We’ve had it with MIS and with the two-incision approach. We need to ask ‘What problem are we fixing? And are we really going to accept these new learning curves? Are we really going to change our implants just to suit an approach?’
There’s a good randomized study that shows that when you’re comparing to the anterolateral approach (Journal of Arthroplasty, 2010), there is a significant difference in early recovery. At two years, however, there wasn’t a big difference at good centers doing good Level I work.
What if you compare with the posterior, or the mini-approach, or the mini-posterior? The reality is the data is just not there in the same way. The reality is that while there may be little short-term benefit, it is not sustainable and certainly, in my mind, not worth the risks that are involved.
Looking at several Level I studies, there are more complications with the anterior approach. There’s a longer operation time, more blood loss. Is that a price worth paying for a slightly better, early recovery? Particularly when you get to 3 months, 6 months or 12 months and there’s no statistically significant difference.
Then there are the disadvantages. A special table. More assistants. How many component malpositions are you going to accept? How many times are you going to have to change your implant? Limited implant fixation options. And that learning curve, which I wouldn’t dismiss so lightly.
There is also good cadaveric data to suggest all you are doing is swapping one type of soft tissue damage for another. There are no free lunches. There is a price for everything.
The Mayo Clinic, a great group, looked at their data and found no systematic advantage of direct anterior versus mini-posterior. If anything, it was the other way. Not surprising to all of us who recognize how good the mini-posterior is.
The direct anterior approach is technically challenging. Lots of data suggests that even good surgeons see risks when they’re doing this approach. They start to cherry-pick their patients. They go away from the big guys. They start to look at their X-rays before they choose patients. One of my partners is a big anterior approach fan but he won’t do it with all of his patients. It’s a difficult exposure. There’s a learning curve. It’s not for every patient.
So which approach you choose will depend on many, many factors, but your approach needs to be simple; it needs to be generalizable, and bear in mind it shouldn’t limit your further options. The anterior approach works in expert hands, as you just heard, but it’s a tough operation, it’s not extensile, and it needs special instruments. It may constrain your surgical choice and it cannot be translated to all of your patients.
And the data, quite frankly, just does not support it.
Moderator Shimmin: Fares, what if I said to you something like this: ‘You’re too young to be old, and you just can’t be bothered changing.’
Mr. Haddad: I’m not that young, but I take it as a flattering comment. It’s not a question of being resistant to change. It’s a problem that whenever there is a change we need to work out what problem I am trying to fix and is this a way of fixing it and what risk is there. Here I think there is a big risk of changing mid-practice.
Moderator Shimmin: What then would convince you to change your practice? Acknowledge the benefits of an anterior approach? Is there anything that will convince you?
Mr. Haddad: It would need to be a sustainable, measureable benefit that wasn’t transient, and that was at no risk or minimal risk to patients. And that hasn’t been demonstrated yet.
Moderator Shimmin: Bill, how long have you been doing the anterior approach?
Dr. Hamilton: Six years.
Moderator Shimmin: Okay, and how long before that were you doing a different approach?
Dr. Hamilton: Six years.
Moderator Shimmin: Why did you change? Or could I put it to you this way…I would suggest that you changed for marketing reasons—that you saw that your practice was going to suffer if you didn’t change.
Dr. Hamilton: It wasn’t so much for market share. For me personally it had to do with trying to be on the cutting edge. To offer this type of training for fellows, to research it and to publish honest results. But I can tell you in all honesty that many surgeons who come to train with me do this for marketing purposes. And that does frighten me a bit and I really try to talk them into a slow and measured and honest implementation in their practice. But you’re absolutely right that marketing is playing a role because the patients are demanding this. Market share is shifting to the anterior approach in the United States and in my own practice. Over the six years that I’ve done the anterior approach now, 70% of the hips done in my hospital are done from the anterior approach and that’s with four surgeons, two of whom do posterior and two of whom do anterior. That’s the reality of it. The question is can we teach surgeons safely so that when they implement in their practice we are not harming patients. I think we can if we harp on this and do the training appropriately.
Moderator Shimmin: Fares, someone comes to you—a new patient—and they’ve consulted Dr. Google and they want this brand new fancy new type of hip replacement. What do you say to them?
Mr. Haddad: I tell them I’ve done it, I’ve tried it. I’ve got partners who do it and I can send them there. But the reality is what they want is an implant that I know is proven; that I can put in well, that will give them a good long-term sustainable result, and that to me is done through mini-posterior in my hands and I will offer them that.
Moderator Shimmin: Ladies and gentlemen, thank the two speakers. They’ve done a super job and answered questions really well.
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Senior Editor: Jay D. Mabrey, M.D., whose 35 year career in orthopedics included residency at Duke University Medical Center, service in the United States Army Medical Corps, Fellowship at the Hospital for Special Surgery and a long, distinguished career at Baylor University Medical Center where, in addition to his overall leadership at that institution, developed the Joint Wellness Program that helped patients get up after surgery more quickly, developed the first virtual reality surgical simulator for knee arthroscopy and chaired the FDA Orthopaedic Device Panel, is Orthopedics This Week’s newest contributing writer and editor.