Lonner v. Haas: Patella Resurfacing: Rarely if Ever Necessary

This week’s Orthopaedic Crossfire® debate was part of the 32nd Annual Current Concepts in Joint Replacement® (CCJR), Winter meeting, which took place in Orlando this past December. This week’s topic is Patella Resurfacing: Rarely if Ever Necessary.” For the proposition is Jess H. Lonner, M.D., The Rothman Institute, Philadelphia, Pennsylvania. Opposing is Steven B. Haas, M.D., Hospital for Special Surgery, New York, New York. Moderating is Kelly G. Vince, M.D., F.R.C.S.(C), Whangarei Hospital, Whangarei, New Zealand.

Dr. Lonner: Kelly, I have this one. I’ll win this debate.

I’m not sure I can stand up here and say never resurface the patella. But I truly believe in my heart of hearts that’s not the right thing to do.

There are a variety of approaches. Many of us will never resurface the patella and some of us will resurface almost a 100% of the time. Then others will selectively resurface the patella depending on the circumstances.

If we look at the appearance of the patella when we’re doing a total knee, somewhere between15% and 60% of patients will have significant patella arthritis. If you start scrutinizing the quality of the cartilage in the lateral compartment and the patella, it’s amazing how many total knees are being done on patients with intact cartilage in various compartments of the knee.

The good news is that when we look at why total knees are failing, very few are failing because of patellofemoral problems. The problem is that when they fail, they fail catastrophically. Resurfacing the patella, while it usually is fine with great outcomes, when they go bad, the outcomes can be really problematic.

I was a 100% resurfacer up until a couple of years ago. I was always looking for an excuse to stop resurfacing when I had a patient who, after resurfacing, had avascular necrosis, fragmentation, devascularization, fracturing, loss of the extensor mechanism, multiple surgeries, extensor mechanism allograft infection, fusion, the whole gamut.

Since then, I’ve been a selective resurfacer and now I resurface only about 40% of my patellae.

There’s a common bias among resurfacers that leaving the patella unresurfaced will result in more anterior knee pain and secondary surgeries. But if you look at the results of total knees with patella resurfacing, using good implants, performed by the best surgeons in the world, the incidence of anterior knee pain can be as high as 40% in some series.

A study by Robert Barrack, (randomized control study with and without patella resurfacing) found that 28% of the patients with a resurfaced patella who did not have anterior knee pain prior to total knee replacement, all of sudden have anterior knee pain after replacement. And in those without patella resurfacing, only 14% of patients developed new anterior knee pain.

Now, as a caveat, if you have anterior knee pain from patella disease or for some other reason, prior to total knee replacement surgery, if you do not resurface the patella you will have a higher incidence of anterior knee pain.

So, there’s a variety of reasons why people get anterior knee pain after total knee replacement surgery. Cartilage wear is only one of the reasons. Most patients have anterior knee pain because their soft tissues hurt. So a study out of Madrid (Rodriguez-Merchan and Gomez-Cardero, CORR, 2010) found that if you have Grade 4 cartilage loss on the patella, and you don’t resurface the patella, you’re more likely to get anterior knee pain and need secondary resurfacing. But if the cartilage is relatively intact, at five years you’re in good shape and most patients don’t need additional work.

If we go in and secondarily resurface the unresurfaced patella, only 50% of those patients get better. Which means, to me, that there is another cause of that anterior knee pain, not necessarily related to patellar cartilage wear.

So, the argument to resurface or not to resurface is an easy one. We can make a very good argument that we can resurface 100% of the time, but I think we can also argue that we can selectively resurface the patella and get very good results. Whether or not we should resurface the patella for “all” depends on what “all” is. I think that we’re best to resurface always if there is severe patellar disease; if there’s anterior-lateral knee pain; inflammatory arthritis; or a patient who needs significant pain medications. Otherwise, it’s safe to use your own discretion and resurface selectively.

Moderator Vince: Thank you Jess. Steve Haas is going to oppose that position. Steve, I assume that you resurface all the time.

Dr. Haas: You would be assuming correctly.

You say not resurfacing the patella is a great idea. And I think you are absolutely correct, if you like to re-operate on a lot of your patients. I attempted to not resurface the patella in a patient who had beautiful looking cartilage and a couple of months after the surgery started developing a cyst on the patella and that cyst kept getting worse. Then I was forced to take that unhappy patient back to the OR, use a biconvex patella and a little bone graft to fill all the defects in the patella. Ultimately a good result was achieved, which as you know only happens about 50% of the time when you have to secondarily resurface it.

So maybe you can get by with this in Pennsylvania. There are nice, sweet people in Pennsylvania who make you pastries and pies. But in New York City, where there is a tougher crowd, if I must re-operate on the patient, I’m likely to have this patient yelling at me and saying: “But doctor, you said you were going to get rid of the arthritis the first time.” Or alternatively they’re going to go to somebody down the block who’s going to say, “The reason why it never got better when I re-operated on it is because the stupid doctor didn’t do it the first time.”

So I think you have to look at the data, not look at a little bit of experience that one person has or even one study. Look at the overall data on this. First of all you can look at the cartilage. You say it’s normal, but Fred Cushner looked at this pathologically—normal is not always normal. So you think it’s normal, but when you look at it microscopically the cartilage is not normal. So it’s diseased cartilage from the start. If you look at the rate of revision or complications, as you pointed out, some of them can be really bad, but really bad doesn’t happen very often. We all see bad, bad things on rare occasions, but the revision rate for patellas out 10 to 15 years, is about 1%.

So what are the results? I’m going to run through a lot of data. These are meta-analyses—5% re-operation rate with resurfaced; 13% non-resurfaced. Meta-analysis by Dr. Bourne.

Another meta-analysis (Nizard) looking at unresurfaced patellae—increased risk for re-operation, significant anterior knee pain, and more difficulty climbing stairs.

Another study by Parvizi, 14 clinical trials looked at, non-resurfaced patellae – greater incidence of anterior knee pain, 8.7% required secondary resurfacing; less satisfaction when the patella was not resurfaced.

Another study, JBJS 2005 (Pakos), 1, 200 knee replacements—patella resurfacing reduces the risk of re-operation and anterior knee pain after total knee replacement.

You’re seeing a common theme in these large meta-analyses and large series of patients.

Another randomized trial (Burnett) of 32 bilateral TKA patients (64 knees), 37% of resurfaced knees were essentially having equivalent results; 22% non-resurfaced felt their knee was better; and 41% said no difference. So, greater percent preferred their resurfaced patella.

If you look at all the literature…and if even if you look at the Swedish knee registry data… 1.4x higher revision rate in the 30, 000 patients without patellar resurfacing compared to almost 9, 000 who had patellar resurfacing. So again, higher rates of revision and more pain.

Resurfacing just makes sense.

Moderator Vince: So Jess, we’ll give you the chance to just give in right now. Or what do you think about all these numbers?

Dr. Lonner: I think Steve’s points are very valid. The one comment I would make is that a lot of the meta-analyses and a lot of even the randomized controlled trials that you looked at are older studies—10 years old, 8 years old—and they have minimum 10 year follow-up which means that the implants that they were looking at were older implants. We know that some of the older boxy-style femoral components were really not friendly to the natural patella. One of the reasons Leo Whiteside championed no resurfacing the patella is that he had already, 15-20 years ago, a uniquely accommodating femoral component that lent itself to not resurfacing.

The other comment I would make is that I truly don’t believe that you can’t resurface or that you shouldn’t resurface anyone. I think there’s a large percentage of patients—in my practice 40%—who should have their patellae resurfaced. But it’s the patients who don’t have significant cartilage wear who can do quite well without resurfacing. And so that’s why I referenced in my talk some of the randomized controlled trials that looked at randomizing, selectively, patients who did not have significant cartilage damage whereas the older randomized controlled trials looked at all comers.

Dr. Haas: …many of these studies were in what they described as patella-friendly implants.

Moderator Vince: Let’s find some common ground here. Steve, would you agree that many patients with an unresurfaced patella do extremely well?

Dr. Haas: The answer is yes, some people do very well. You can do it but it is imperative that you have a discussion with the patient. In other words, if you’re going to not resurface the patella, it maybe the patient’s preference, if you have a very young patient who you want to preserve bone…but I think it is imperative that you tell the patient, “Listen, your chance of getting re-operated is a lot higher.”

Moderator Vince: Do you inform patients that you will resurface the patella pre-operatively?

Dr. Haas: Yes.

Dr. Lonner: No, I don’t tell them either way. But it’s an interesting dynamic in my office. Since I do a lot of partial knees, a lot of patients come to me hoping for a partial knee. I’ll tell them in the office, more often than not, that they are not a candidate, that they need a total knee. But when I leave the operating room if I don’t have to resurface the patella, I come out and I say to the family: “Good news is I didn’t have to resurface the patella.” They all think I’m the Messiah.

Moderator Vince: Very sly, very sly. But I look to you and all the things you’ve written when I think of doing a patellofemoral arthroplasty. Do you ever not resurface the patella in a patellofemoral arthroplasty?

Dr. Lonner: No, that would be crazy. The reason I don’t do that is they’re coming to me specifically for the treatment of anterior knee pain. I want to eliminate the possible variable of cartilage wear.

Moderator Vince: Steve, I think that secondary patellar resurfacing works very well for me in selected patients that I’ve evaluated extremely carefully. Why do you think the literature tells us that secondary resurfacing is so poor?

Dr. Haas: I think Jess said it. We don’t all understand exactly why people get patellofemoral pain and probably some of it is soft tissue and remember it is still transmitting loads even when you resurface it. Maybe even higher loads. So I think that some people are just prone to getting patellofemoral pain no matter what you do.

Moderator Vince: Gentlemen, thank you very much.

Please visit www.CCJR.com to register for the 2016 CCJR Winter Meeting, – December 14 – 17 in Orlando.