Dorr v. Taunton: The Mini-Posterior Approach: Evidence Over Eminence

This week’s Orthopaedic Crossfire® debate was part of the 34th Annual Current Concepts in Joint Replacement® (CCJR®), Winter meeting, which took place in Orlando. This week’s topic is “The Mini-Posterior Approach: Evidence Over Eminence.” For is Lawrence D. Dorr, M.D.,Keck Medical Center of USC, Los Angeles, California. Opposing is Michael J. Taunton, M.D., Mayo Clinic, Rochester, Minnesota. Moderating is Robert T. Trousdale, M.D.,Mayo Clinic, Rochester, Minnesota.

Dr. Dorr: I think I’ll begin by using my closing summary, which is that I really don’t care which approach anybody uses to do a hip replacement as long as you do it well.

I think the elephant in the room is whether the marketing for direct anterior approach is making them believe they have to have that operation to get a good hip replacement. Why are surgeons pressured to think they have to do that approach to attract patients? Why do we in orthopedics—when we have such an honored profession—have to promote an approach that is 10% of the operation that we do…and have the public believe that it gives better outcomes when there is no data on the outcomes.

Do you know that there is not one paper published with good patient results past six months to one year for the direct anterior approach?

It seems to me that it’s kind of weird that a surgeon will do a new operation that has no outcome data, has a long learning curve, has no better dislocation rate and more fractures…and actually has the only data in the literature saying that it’s better during the first two weeks.

I’ve never had a patient come in and say, “I just want a two-week operation.”

Where have the stewards of orthopedics been with this controversy? Why haven’t we heard from the AAOS or AAHKS as to rebut all the marketing that says that incision gives a better hip replacement. Sixty percent of the membership does a posterior approach…that 60% right now is under the bus. So, I stand here today to speak for the posterior surgeons and to say that the 10% of the operation that you do allows you to very well do 100% of the reconstruction.

The issues are three: one is muscle injury. I think the tag line, “No muscle cut” was what really started this whole charade.

Interestingly, there isn’t any real difference if we look at the muscle damage done as judged by gait analysis. Interestingly, Joel Matta has often told me the big advantage of the direct anterior approach is that it doesn’t cut the obturator internus muscle, and that’s the most important external rotator. But a paper published in August 2017 (Kawasaki et al, J Arthroplasty) showed that the muscle damage was greatest—of all the muscles—to the obturator internus. That’s ironic.

Recovery has been a big issue too, but we all know that what we tell the patients is what they are going to do. If you tell the patient they’ll go home the same day then they will go home the same day. If you say they’ll stay five days, then they’ll stay five days.

And how about outpatient hip replacement? I’ve been doing that with the posterior approach since 2005. Today, all the excited people doing hip replacement with outpatient surgery using an anterior approach think they invented it with that approach. But our articles on the posterior approach were published some time ago. And we basically all know that the reason we’re able to do much more rapid discharges is because of our multimodal pain management, which we’ve all converted to over the last 10 years.

Tissue inflammation occurs no matter what operation you do on somebody—as soon as you cut then you’ve got it. And when you injure the bone you’ve really got it. And by the way the best treatment for that is not the approach, but just give them ice for the first couple of weeks after surgery.

Lastly function. Is it really better if you don’t cut any muscles? At three weeks postoperatively with the posterior approach: 98% of our patients could walk a mile…which is the only therapy I use…I just tell them to walk. And two-thirds of them were back at work. Isn’t that the ultimate recovery for somebody who wants to be productive when they do the operation? I don’t think I’ve seen any data published, not any, with the anterior approach as good as that data.

How about outcome? I told you that there aren’t studies with the direct anterior approach. But there are three, at 10 years, with the posterior approach: ours (J Arthroplasty2016), one from Mayo Clinic (Abdel et al, J Arthroplasty2017), and Beverland’s (Stevenson et al, JBJS-Am2017). They all showed excellent results.

My conclusion is that if you do the posterior approach to a hip replacement you should be proud: you’re among the majority, your results are the best, and when you walk out of here today, just walk out with your hands like this (raising fist).

Moderator Trousdale: Larry, I do the posterior approach and I’m feeling proud. Michael is my friend and partner and I think he’s going to give you a reasonable argument for why some surgeons should consider the direct anterior approach.

Dr. Taunton: In the early 2000s we saw that less invasive procedures can cause less muscle damage, can improve early outcomes, while maintaining radiographic outcomes, a low complication rate, and acceptable long-term outcomes. In 2017, we demonstrate, among the AAHKS members, an eminence of the posterior approach, with 56% of the surgeons utilizing that approach. I would say a majority would consider that as a less invasive approach than the approach they were using 10 years ago.

There is a lot of evidence and scientific rigor that has been applied to the miniposterior approach. Dr. Sculco in 2005 demonstrated decreased length of stay (LOS), limp and blood loss (J Arthroplasty). And Dr. Dorr in 2007 (JBJS-Am) showed decreased LOS, gait aids, and pain. My partner, Mark Pagnano, in 2008 found a decreased need for gait aids and improved early activity (JBJS-Am). But we can see that over the last nine years the change has been coming in the eminence. While the posterior approach is still pre-eminent, the direct anterior approach has made gains.

Given that the posterior approach has been very well studied and the direct anterior approach has not been studied as well, we need to look at things a little bit closer. My prediction is that the eminence of the posterior approach will fade as the direct anterior approach is clinically superior.

But is there evidence?

I designed a prospective randomized trial on the direct anterior approach and the mini posterior approach, looking at in-hospital outcomes, the patient’s early gains in daily activities, radiographic outcomes, and one-year complications.

All patients received the same standardized perioperative pain and physical therapy (PT) protocols. Patients were recruited from the practices of surgeons participating in the study. They were randomized for surgeon, age, gender, and body mass index (BMI). I performed all of the direct anterior approaches no matter who the initial consulting surgeon was, and likewise with the posterior approach, the posterior approach surgeons performed those surgeries. The initial consulting surgeon continued to follow the patient postoperatively no matter what approach was performed.

We gave the patients a home diary to record their daily functional milestones at home. We also used the proprietary ambulatory activity monitors preoperatively, at two and eight weeks, and one year. This allowed an objective evaluation of physical activity over a course of five days and in the daily living environment at those time points.

The direct anterior approach patients used less pain medication, overall had less pain, and were able to walk further with physical therapy in their first PT session. Looking further at early functional recovery, we saw that the direct anterior approach patients were able to discontinue their gait aids a week before the posterior approach patients. They were also able to discontinue their walker and narcotics, able to ascend stairs and walk six blocks—all about five days earlier. Looking at the steps per day at two weeks, there was a significant difference: 1,800 steps more per day for the direct anterior patients than the posterior approach patients. There was no difference at eight weeks or one year.

There was no difference in radiographic outcomes between the two groups. The overall complication rate for the posterior approach was 10% with one dislocation, one wound problem, two calcar fractures, and a deep vein thrombosis (DVT). For the anterior approach there was one dislocation, two wound dehiscence, and one fall resulting in a pubic rami fracture. This randomized controlled trial had a well-matched cohort with a unique surgeon crossover design that focused surgical expertise and decreased bias in the rehab phase.

As for longer term outcomes, I will point you to a couple of registry studies.

The Kaiser group had 118,000 patients with an average follow-up of three years: no difference in revision (septic or aseptic) or dislocation rate (Sheth et al, CORR2015). Recently, the Dutch Arthroplasty Register reported an overall dislocation rate for the posterior approach at 1%, and dislocation for the anterior approach at 0.59% (Zijlistra et al, Acta Orthopaedica2017). There was no difference in the overall revision rate.

In conclusion, both the direct anterior and the posterior approach really did provide excellent early postoperative recovery with a low complication rate. However, the direct anterior approach patients had an objectively faster recovery as measured by shorter times to achieve a number of functional milestones, and by quantitative activity monitoring at two weeks. Additionally, some new long-term studies are showing a reduced long-term dislocation rate..

Moderator Trousdale: Can we agree, Larry and Michael, that done well, both the direct anterior approach and the mini posterior approach do well for our patients?  Is that a true statement?

Dr. Dorr: That was my opening conclusion and my closure is that I don’t care what you do as long as you do it well. Unfortunately, I think there’s too many people not doing the anterior approach well because there are too many complications.

Moderator Trousdale: Michael, you showed a graph projecting that the direct anterior approach will overcome the posterior approach. How much of that do you think is marketing versus it will take over because it is really a better approach in the short and long-term?

Dr. Taunton: I think the answer is “yes” to both. There is patient pressure due to marketing. It’s certainly out there. I do think that part of the growth will be as there are surgeons in fellowship training programs that are performing the direct anterior approach, and then taking that approach into their practice.

Moderator Trousdale: We don’t have many marketing issues in Rochester because we live in a farm town in southern Minnesota, but Larry lives in a city that may be the pinnacle of marketing. Larry, tell us how prevalent you think marketing is in your region of the country, and what do we do about it as a society because it’s certainly an issue, I think?

Dr. Dorr: Marketing is very heavy for the anterior approach, at least in California/western United States, and part of it around L.A. is because Joel was there…for surgeons to think they had to compete with Joel a lot of them converted to that approach.

And the fact of the matter is that I am a little disappointed that our leadership hasn’t responded to the marketing and hasn’t supported the posterior surgeons. There’s been no support. The companies—every one of them—are the ones really promoting this because they are trying to sell implants through an approach.

There needs to be a counter marketing to the public to let them know that there isn’t any difference.

Moderator Trousdale: In defense there is some data, though. I still think the posterior approach in my hands is better than the direct anterior approach. You’ve got to weigh the pros and cons. Larry, does the direct anterior approach win on early instability?

Dr. Dorr: Yes.

Moderator Trousdale: And Larry, does the direct anterior approach win on early recovery at weeks one or two?

Dr. Dorr: No.

Moderator Trousdale:Michael?

Dr. Taunton: Yes.

Moderator Trousdale: We’ve got nice consensus there.

Dr. Dorr: Everybody is going to believe their own data. He’s got his data; his patients recover. But my published data shows what my patients do, and it’s out there for both three and six weeks. And his data has got to beat that before he’s going to say he is better than I am.

Moderator Trousdale: Well, he has a comparator group.

Dr. Dorr: Yes, but that’s at Mayo Clinic.

Moderator Trousdale: Fair enough. Which was a lot quicker recovery….

Dr. Dorr: If it was Hospital for Special Surgery we might believe it.

Dr. Taunton: That was a dig, ladies and gentlemen.

Moderator Trousdale: Femoral fracture rate, Michael? Should we assume the early femoral fracture rate is a little higher with the direct anterior approach versus the posterior approach?

Dr. Taunton: Absolutely. I think the early fracture rate is higher with the anterior approach. We see in numerous studies—you’ll see in that Norwegian registry that although the dislocation rate was lower, the rate of femoral failure was higher in the direct anterior approach, which is what caused the revision rate to be similar.

Moderator Trousdale: Michael, before we finish this can you comment on skin issues? Some people think that the skin issue is a little bit of a bigger deal with the direct anterior approach versus a side incision. Skin issues with the direct anterior? Who wouldn’t you do the direct anterior approach on?

Dr. Taunton: We looked at this and patients that are female, diabetic, with BMI greater than 40 had an almost 19% risk of having a wound complication of any type. Therefore, in those patients I do tend to go to the posterior approach.

Moderator Trousdale: Thank you, gentlemen. Well done.

Please visit www.CCJR.com to register for the 2018 CCJR Winter Meeting, – December 12 – 15 in Orlando.