Evan F. Ekman, MD: Well, let's advance to the fun part of the night and our first talk is going to be entitled, "Improving Patient Satisfaction Through Technique" and we're going to learn about a minimally invasive approach to total knee arthroplasty. It is an absolute pleasure to introduce Dr. Peter Bonutti and I'm sure you all have heard his name before; he's the founder of the Bonutti Clinic. He's an Associate Clinical Professor at the University of Arkansas and one thing that I learned about him that's absolutely amazing to me is I think he holds something like over 170 patents -- a pretty impressive number. So myself as well as everyone else here is looking forward to hearing him. Thank you very much.

Peter M. Bonutti, MD, FAAOS, FACS: Thanks very much. We'll talk a little bit more about technique, which is probably a little closer to my heart than some of the pharmaceutical options, although the pharmaceutical options are very, very important. Let's see what we've got.

Our goal with this, with minimally invasive technology, was really to look at issues that patients had, to try and address patient satisfaction and patient-related issues. I think it's real important as we look at knee arthroplasty in general, we need to understand not just what surgeons consider important factors -- survivorship and success rates -- but what patients really are concerned about.

We do know that total knee arthroplasty is a very successful surgery; FDA panel and consensus panel has suggested that total knee arthroplasty is cost-effective and safe for alleviating pain and it does have good long-term survivorship.

But are patients really as satisfied as surgeons are? Here's a recent article just in February 8, 2005, in The New York Times and it kind of gives us a different flavor of what's really going on.

Here's a patient who decided to undergo bilateral total knee replacements by a well-respected surgeon. His neighbor tells him he had his knee replaced and he said the first 4 weeks are hell. And here's the patient at 3 weeks after surgery; he states that he's moaning and crying and despite narcotics and icing, his knees are killing him. And the article finishes by stating: I'm still waiting for the blissful day when I can walk better than I did before surgery, get through the day without multiple pain pills, and sleep without pain medication. Now, again, this is just a case, but this was what's published recently in The New York Times, suggesting that patients' experience with knee arthroplasty is significantly different than what surgeons look at.

And this is a follow-up article, just a week later and talks about doctors maybe not understanding how to manage this pain.

Again, this is the same patient, another article, kind of making us look not so good as orthopedic surgeons, taking OxyContin and 10 Percocet a day -- I don't think I've ever prescribed that in my life! And then the severity of his pain had him crying and no surprise that his pain was unrelenting. He said: I know of an orthopedic surgeon in New Jersey who won't see his patients for 2 months after surgery because he doesn't want to see them when they're suffering. And then the final quote -- this is again The New York Times! -- as it turned out, my internist knew more about treating pain than my surgeon. So again, it makes us in a little bit of a bad light and it suggests that we may need to revisit knee arthroplasty, especially from the patient's perspective.

Another interesting factor is that the studies suggest that 2.2 million patients in the United States have severe, moderate to severe osteoarthritis of the knee. But less than 1 out of 5 of these patients choose knee arthroplasty to relieve their pain -- and why is that?

I think that question is unanswered, but clearly pain may be a factor.

In the past, we've looked at approaches and techniques which are best for the surgeon -- allows us best visualization in alignment and positioning; clearly, we want long-term and excellent results.

But then you look at these scars and patients compare these scars with the standard total knee replacement, they look at that and they go: This must hurt, and they're very afraid of this. And the question is: Is this best for the patient? And I would propose there needs to be some alteration in our technique that may help patients.

Now let's look at things from a different perspective. Dickstein published an interesting article, knee arthroplasty patients rated successfully by their surgeons.

And one-third of patients said they were dissatisfied with their operation.

That pretty daunting statistic says maybe we don't understand what our patients care about, and this might be mirrored by a recent study at last year's Academy by Esler looking at the British Knee Registry on 4600 knees. And he found that only 80% met expectations and 30% had problems with a significant amount of pain in these patients, even after successful knee arthroplasties.

And his conclusion was the results of knee arthroplasty in general settings don't match published series.

Trousdale looked at a very interesting paper trying to assess patients' fear before hip and knee arthroplasty and what he found, if you look at the patient's perspective, their two greatest concerns were pain and length of recovery. And I think that's important; we need to understand what patients want from us.

And Bullens, looking at patients' success rate in Knee Society scores, found that the concerns and priorities of patients and surgeons differ, that our scoring systems may not be accurate assessment of what patients really care about. And the conclusion of the article is that surgeons are more satisfied than patients. Well, that's worrisome; I think we should be as satisfied as our patients are or maybe be as honest to ourselves as patients.

On the functional side, I think we also have a problem. Mont, at this Academy, has presented a paper soon to be published on his patients with a high Knee Society score, over 90, minimum 6-month follow-up, and only 35% of patients said they could do everything they wanted to. And in the younger subgroup under 60, only 13% of patients said they had no restrictions in their activity, which means not only do we have issues of pain and satisfaction, but our patients may not be doing the activities that they want to do.

And how many patients can kneel, squat, do all their functional activities?

This was recently presented in Orthopedics Today by the Insall Scott Kelly Institute; they talked about how total knee arthroplasty can be an option for the young, active patient, yet he tells the patients you'll never kneel on this knee comfortably, so gardening and descending stairs may be a problem. And in their study, only 24% of their patients remained active, so this is kind of an interesting study.

So young, active patients do well with total knees; if they're inactive? Kind of confusing.

And I think that has a lot to do with our approach and again, this is what's pushed me towards looking at minimally invasive techniques, and this is quantified to some degree by Silva and Schmalzried in their article in Journal of Arthroplasty.

And they found successful knees, through a median parapatellar approach 2 years after knee arthroplasty, with isokinetic strength, had a reduction in their quadricep strength by 30.7%. And this may explain some of the functional deficits that these patients have.

Ormonde Mahoney working with Tom Schmalzried looked at a different study trying to do a simple test of getting out of a chair without using your arms.

He called that "unassisted chair rise" and he found that 3 months after surgery, only 40% with traditional knees could get out of a chair and at 6 months, only 64% could, which means that quadricep is significantly affected.

And here's one of our patients, a standard patient 3 weeks after his minimally invasive knee arthroplasty. But the patient basically has a very simple unassisted chair rise, is able to use his quad function reproducibly. He's got good strength and this man was back to farming and climbing his tractor and working on his combine 2.5 weeks after his knee replacement. Pretty normal gait and this patient is satisfied; he's back to his life 3 weeks after surgery and that's what's driving us.

Now there's also marketing issues and issues about what's going on with direct patient marketing and trends in medicine, and the trends in medicine are suggesting that currently only a small percentage of joints are being done with minimally invasive surgery. They predict, however, in the next 5 years it will be the most common approach for hip and knee arthroplasty.

This is mirrored somewhat in the unicompartmental knee literature where you look, and the unicompartmental knees prior to 2000, only comprised 1% of the knee arthroplasty market. Yet if you look in 2004, over 10% of the knee arthroplasty market is uni's and that's in large part due to minimally invasive techniques, I believe. So it's a big, big jump in the sector of the market and patients are looking at and demanding some of this MIS.

Another interesting paper, Price in the Journal of Arthroplasty, looked at unicompartmental knees, one variation only -- a standard incision where he everted the patellar and a short incision where he did not evert the patella.

And what he found is that the short incision, noneverted patella, recovered two times faster in his uni's and three times faster than his traditional total knee.

So if we avoid everting the patella and use some kind of muscle sparing approach, can we obtain the same results in total knee arthroplasty?

Now I will propose MIS is patient-driven and we need to listen to our patients. Cosmetics are an issue; we can't avoid that. Pain recovery, we don't know issues, however, about long-term function, but clearly the goal is to reduce the overall soft tissue trauma -- not just simply a smaller incision; we need to look at what's inside.

And patients are reading articles like this where they're starting to demand MIS and it's direct patient issues I think are challenging because surgeons need to develop these techniques and they're being pushed into it, which can be a problem.

With total knees, the problem is the implant's not minimally invasive-friendly and we really don't have great literature about it. There's only one paper with a minimum of 2-year follow-up.

The position of that large femoral component, especially this tibial keel, can be a real difficult problem.

And so we recommend looking at an evolutionary approach to looking at these techniques, gradually downsizing your incision, evolving into a lower, smaller incision, deciding where your incision precisely should be, and maybe whether a multi-incision approach. Remember that you can always extend your incision any time during surgery, but you cannot shorten it.

And you evolve from incisions like this, gradually coming down to where I think patients are looking at this true minimally invasive type approaches.

You need to understand how to use these downsized instruments, become comfortable with them with your standard approach, then learn to avoid everting the patella, and then develop muscle sparing techniques and in situ bone cuts.

So start like this, get used to the instruments with your standard technique, and then progressively downsize.

These are the approaches so far that have been described for minimally invasive knee arthroplasty, a number of different techniques -- medial lateral, quad saving, mini midvastus.

Basically these are the quadriceps exposures and you can see the median parapatellar effects. When you cut into that, it affects all four of the quadriceps muscles. The quad saving approach really is a modification of the median parapatellar, then we do a midvastus variation of the VMO snip or mini midvastus, subvastus, or lateral approaches; these are the approaches that have been described. But I'll propose to you that this is not the main reason why patients go home faster or have less pain; it is one of the variables.

And this is a surgical picture showing with the quad saving approach where you detach the entire tendon of the vastus medialis, the midvastus where you go into the muscle and split along the fibers or the subvastus.

They all have similar features and they use reduced incisions, mobile windows, muscle sparing approaches, but all of them avoid everting the patella and do cemented knee arthroplasties.

We've used a number of different techniques -- median parapatellar, midvastus, subvastus in preselected patients.

We do navigated approaches and lateral approaches; some of them are quite challenging and I would caution you to approach these very carefully because you have significant patient preselection. The navigated approaches, Bill Hozack will talk about later I think, certainly has some advantages and he'll talk about those.

This would be a VMO snip.

This is how we approach it, some of the instrumentation.

This is a subvastus approach with your exposure; this would be a subvastus with navigation, just some quick views.

And here's a direct lateral approach, which we'll spend a little more time on later.

But the reason I like the midvastus is because I think it's extensile and it's universal. Since 2000, I've used it on all my primary total knees unless they've had prior surgery.

We found that a number of studies, both Dalury and White and others, have found that it offers early advantages and less pain and faster recovery, and all came up with the same conclusions. And Cooper found that as an extensile approach, you can split the VMO up to 8 cm safely without any neurovascular injury.

The mobile soft tissue window is very important to understand and understand how each bone cut opens up the next space, and this can be universal and it can be extensile approach.

And this is a schematic of how we do it. We cut into the muscle; we mobilize the patella, sliding it out of the way, not everting it. We make our tibial cut to expose the femur, then we make our femoral cut and that allows us to expose our patella further, so in a sequential approach.

So here are some surgical vignettes; here's our VMO snip with the knee flexed about 45 degrees; we just cut about 1.5 to 2 cm into the muscle encapsule, and then do a median parapatellar--a median, a patellar approach. With this knee, it's a varus knee, we do our varus release.

And here you can see the snip in the musculature; it's not extensive, okay, and you can see it's about, in this position, about the 10 o'clock position on the patella. We've not gone to the superior equator of the patella and that's basically our approach. The trick is how to get the patella out of the way and this is probably the most useful slide; we go into full extension and it's very useful to release the fat pad and anterolateral attachments of the lateral meniscus to this fat pad. And you say it's daunting; I can't get the patella out of the way. But if you release this down to the tibial tubercle, down to the patellar ligament, and release this fat pad over and then combine this with a superior release -- see, I can put my finger all the way to the anterolateral tibia -- then that allows us to mobilize our patella and slide it out of the way.

Now with the patella slid out of the way, you have easy access with these downsized instrumentation. Here, we elevate the quad muscle; we don't cut into it and our knee is only flexed about 50-60 degrees and then we would pin this in position, setting our rotation. I use an anterior referencing approach but you can also use a posterior referencing approach and look at a number of soft signs. The drawback is we cannot see our epicondyles, so it makes it very difficult to set up the rotation if you're epicondylar-based rotation, but we use other soft signs as the tibial cut, white sides lined, the anterior femur, the grand piano sign, and the tibial cut in that inflexion. You can see here most of our surgery is done in about 45 degrees of knee flexion; when you flex the knee further, there's more tension on the skin and the quad mechanism and it tears more. So if you decrease the flexion, it allows more mobility of the muscle, it slides it out of the way, and with these downsized instruments, you can make your bone cuts in a very reasonable and reproducible fashion.

You need to take your time and pay attention to detail, so this is our distal femoral cut. I just wanted to show you how you can decrease the quad tension.

Then downsized instruments for the 4 and 1 cut, and again these downsized instruments really help because the patella is not everted, so it pushes on this. And then if the cuts aren't complete, you can use the bone cuts themselves to finish the cuts.

The biggest issue is the tibial keel or tibial fixation and this is the first time we're delivering the tibia anterior to the femur; it's what we call in situ bone cuts and so you want to make sure that you have adequate exposure for the tibial keel and cement pressurization. This can be difficult; you need excellent muscle relaxation from anesthesia. And here you'll see how we pull the muscle out of the way; we use this Goulet retractor, which is very muscle friendly, and you can see sequentially you have adequate exposure.

You have to have good cement technique, good pressurization, so we can hopefully have the same long-term survivorship. We're trying to do the same technique with sparing the muscle and downsizing the approach. And then here we impact this, making sure that the implant is in good position, not flexed, and have a good cement mantle all around the entire implant. The biggest pain, however, is removing all the cement, especially laterally. You have to spend a lot of attention to detail getting all the cement out because it can be a very big problem and a source for complications.

Here's our knee after surgery at full extension, flexion. We believe that because you're not dislocating the joint prior to cuts, you have excellent posterior capsular stability, and there are some interesting new studies coming out of New York that suggest that you have less capsular disruption.

This is our pop test to test that the patella is tracking well, and here you can see that you don't have undue soft tissue trauma if you pay attention to details and learn the position of your leg from flex and extension. Our muscle is not macerated and it's a very reasonable approach and it can be done in all patients. A simple post-op x-ray.

But here are the great advantages -- not some highly preselected patient; this is a typical patient I see in my practice, a small town in Illinois. And this patient is a typical what I call a two-gown patient because it takes two gowns to get around her! But she's the one who really needs that quad function and look at her as she is able to actively flex and extend her leg 36 hours after surgery. She's had one physical therapy session prior to this and you can see she has good active control of her quadriceps muscle. And this is even more difficult, getting out of a chair and getting back into bed and this lady, although she's limping, she is not normal; she is able to do it without an assisted device and she's able to bear full weight on that leg, so she can start to navigate. When she goes home, she will be using the cane and she has excellent muscle control. And I would suggest that this is not purely an analgesia issue; these are patients who have better quadriceps function, which is what they're really looking for.

Here's another patient, simultaneous bilateral total knees, 4 weeks after surgery. He has excellent quad function, you can see here with this unassisted chair rise, even tougher on tall patients. Good quad function. He was able to get back to his life and this individual, when he saw us, he's got a little bit of a limp but not too bad. And here he is, he was already golfing at his 4-week visit, which I think is very impressive with bilateral knees.

Quick literature review: a number of papers in the literature, 13 in total, only 6 of them discuss clinical results and only 1 of them has a minimum 2-year follow-up, which we think is necessary to adequately critique these.

We looked at our series just recently published in JBJS with a minimum of 2-year follow-up, 216 knees, and we used the Stryker Scorpio Knee System, very happy with the results.

We did have reasonable results with 97% excellent results, patients pleased with the cosmetics. There were a few minor complications; we did have 6 manipulations under anesthesia and we did have 5 reoperations, so early in our learning curve, we did have a little bit high reoperation rate.

Knee Society scores averaged 95.8, pretty reasonable for these patients on the pain side.

On the functional side, 92.6. Here are our functional scores.

Again, tibiofemoral alignment; are we putting these in as good as traditional knee arthroplasty? I can tell you we do have some outliers; you can see that 0, 1, 2 degree, we need to eliminate those; we're working on improving the instruments. But again, these were with our first-generation instrumentation.

And here were our open reoperations. We did have two component revisions, one because of poor cement technique on the tibia and one because I probably overhang, I put too large a tibial component and they had lateral tibial overhang. We had one hematogenous infection, not surgical-related, one chronic effusion, and one patient who did have traumatic laxity. Most of these were in our very, very early procedures.

Here's my worst case and I think that was just bad cement technique and that's why I tell you, you have to be very cautious about good pressurization and good cement technique.

We also had a subgroup of patients who had standard knee on one side (24 patients), and minimally invasive on the opposite side, a minimum 1-year follow-up. All 24 patients recovered, by their own standards and chart reviews, 4-8 weeks faster when we compared it to their standard knee arthroplasty. Twenty-two of the 24 preferred the MIS approach, one didn't really care at follow-up, and one actually preferred the standard approach; so not everybody likes this.

That was a male who was in a pretty high demand farming job and he felt that the standard knee gave him a little bit more stability, so he liked it. But patients do prefer the cosmetics of this approach.

We've also presented at this Academy meeting a direct match comparison of our standard vs our minimally invasive.

Early in our study, a little difference in surgical time, a little less blood loss, definitely less narcotic use and less time with narcotics. Patients with the standard knee required narcotics for up to 12 months in some groups and this minimally invasive approach may help some with this.

Functional recovery was definitely improved with the minimally invasive; with a standard, 59% still use the walker at 2 weeks, with the MIS, 16%. And the MIS had independent ambulation at 3.5 weeks whereas the standard had 8 weeks.

We also published on some suspended leg, which we adapted from sports medicine literature and allows you to go from uni's to totals, hanging the patient over the edge of the bed.

We also presented this at this Academy as well, 3 year follow-up.

Knee Society scores were pretty good with the suspended leg.

Functional recovery mirrored the same type of results.

But in general, these MIS had problems; there are complications and we need to understand them. One, reduced visualization, which may affect injuring the patella, and removal of osteophytes and cement.

And here are some of my complications where I left cement laterally; you have to take care. And removal of posterior osteophytes can be a problem. But what's making this interesting?

Well, here's a patient -- why should we do MIS?

Here's an isokinetic test, 3.5 weeks post total knee. The right knee, minimally invasive knee; the left knee was normal. And 3.5 weeks post-op, the minimally invasive knee was actually stronger on isokinetic testing than the opposite knee, not like the Schmalzried find where it's 30% weaker.

And here's another patient with a standard total knee 5 years after surgery and minimally invasive 6 months after surgery; the right knee was 15% stronger than the left standard knee. But we're following this up; we'll hopefully present this at next year's Academy but we're seeing some hard data now that suggests quadricep strength is affected, and that by doing some of these muscle sparing techniques and noneverted patella, we may help these patients.

Other quick studies: by Haas, again, a short-term study with a similar approach to ours. He has only 1 year follow-up so a more recent study, reasonable alignment. He did have a few complications, one skin necrosis.

But if you look, his range of motion is better; Knee Society scores were a little better.

Dick Laskin, another study, again, a similar type approach, a midvastus variation.

And again, similar to ours, and what he found is a significant reduction in post-op narcotic use. So we have three separate authors who are published now who suggest this midvastus approach is reasonable.

But one caution is that too many people equate minimally invasive without patient surgery. And I want to stress that we need to look at this because Ottenbacher did a study looking at decreasing length of stay with orthopedic and neurology patients, and they found when they decreased the stay, the mortality rate increased significantly. And this was actually picked up and was front page in our local newspaper, so it's something to be aware of. Sending patients home too early from these big surgical procedures has medical as well as surgical risks.

So you need to be aware of it and rapid discharge may not necessarily be the goal of minimally invasive surgery; a lot of other factors other than what you do to the quadriceps may affect rapid discharge -- selection, anesthesia, psychology, rehab protocols, and injectable cocktails.

And I'd caution you on some of these injectable cocktails because surgeons use a lot of steroids now.

And if you're sports medicine-trained like I am, we know that steroid injections, especially Depo-Medrol, into an arthroscopic wound has a significantly greater risk of infection, published in two separate studies. So intra-articular steroids with total knee arthroplasty I think is a big risk and should be avoided.

A couple of other just quick approaches, a lateral approach that's fully computer navigated.

This is kind of where the future is going so I thought I'd throw a few slides up on this, just a lateral incision. We open this up; we do not denervate the skin. The incision is directly lateral. We remove the bone laterally, slide this out with in situ bone cuts, and don't affect the quad mechanism at all. Slide the tibial and femoral components in; it does require a new type of implant and it can be fairly exciting. Here's one of our surgical pictures, so we think that the future may be going this way as well.

Possibly arthroscopic-assisted using it as a light source and for magnification.

And here are some arthroscopic pictures; we're using that as well.

So evolution vs revolution: We need to understand this is a complex difficult procedure. We recommend evolving into this; you need to understand anesthesia will optimize muscle relaxation, and you have to take your time and pay attention to detail, gradually becoming comfortable and then downsizing your instruments.

We published an article and this would be our suggestion on how you should approach any type of minimally invasive technique.

And here's a patient who I did; it's something new we're doing with minimally invasive revisions as well and primary MIS totaling 3 days after simultaneous bilateral surgery. And the patient states that he went home from the hospital on Saturday and he went dancing with his wife the day of discharge. And he said he's been dancing ever since. And here's a patient for his follow-up checkup and you can see, with even a revision on one side and a primary in the other, he's getting pretty reasonable function. And this patient is what we're really looking for; it makes us gratified to spend the extra time and effort.

So we suggest not all techniques are the same; three separate authors have suggested midvastus variations are reasonable -- I would consider that. I do think these other approaches are risky, radical, so you need to really follow these through a little bit with a greater risk for complications.

So, in summary, MIS really is an attempt to address patient goals, not surgeon goals, and trying to address pain, rehab, and function. I think it should be done in evolutionary fashion and make sure it's safe and effective. Thank you.

Dr. Ekman: Well, Dr. Bonutti, thanks so much. I'll tell you, I love that video of your last patient. I think that the smile on his face, it probably has everything about what it is to be an orthopedic surgeon; really, it is an opportunity to make a difference in people's lives.