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CME

Clinical Counterpoints: New Techniques in Total Knee Arthroplasty and Pain Management

  • Authors: Faculty: Evan F. Ekman, MD; Peter M. Bonutti, MD, FAAOS, FACS; Kirby D. Hitt, MD; William J. Hozack, MD
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Target Audience and Goal Statement

This program was designed to meet the educational needs of orthopedic surgeons and other physicians involved in the surgical management of joint pain and postoperative pain management.

Upon completion of this activity, participants will be able to:

  1. Identify predictors for improved patient satisfaction after orthopedic surgery.
  2. Explain the concept of multi-modal analgesic therapy, and discuss its place in pain management.
  3. Discuss different surgical and navigational approaches for TKA.

 


Disclosures

Postgraduate Institute for Medicine has a conflict of interest policy that requires course faculty to disclose any real or apparent commercial financial affiliations related to the content of their presentations/materials. It is not assumed that these financial interests or affiliations will have an adverse impact on faculty presentations; they are simply noted here to fully inform participants.



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    Credit Statement

    The Postgraduate Institute for Medicine designates this educational activity for a maximum of 3.0 category 1 credits toward the AMA Physician's Recognition Award. Each physician should claim only those credits that he/she actually spent in the activity.

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CME

Clinical Counterpoints: New Techniques in Total Knee Arthroplasty and Pain Management: Improving Patient Satisfaction Through Technique: Minimally Invasive TKA

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Improving Patient Satisfaction Through Technique: Minimally Invasive TKA , Presented by Peter M. Bonutti, MD, FAAOS, FACS

Are Patients Really Satisfied With Total Knee Arthroplasty?

  • 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.

  • Improving Patient Satisfaction Through Technique: Minimally Invasive TKA

    Slide 1.

    Improving Patient Satisfaction Through Technique: Minimally Invasive TKA

    (Enlarge Slide)
  • 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.

  • Slide 2.

    (Enlarge Slide)
  • 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.

  • Slide 3.

    (Enlarge Slide)
  • 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.

  • Slide 4.

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

  • Slide 5.

    (Enlarge Slide)
  • 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.

  • Slide 6.

    (Enlarge Slide)

Is What's Best for the Surgeon Best for the Patient?

  • 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?

  • Osteoarthritis -- US 2003

    Slide 7.

    Osteoarthritis -- US 2003

    (Enlarge Slide)
  • I think that question is unanswered, but clearly pain may be a factor.

  • Osteoarthritis -- US 2003

    Slide 8.

    Osteoarthritis -- US 2003

    (Enlarge Slide)
  • 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.

  • Approach Best/Easiest/Fastest for Surgeon

    Slide 9.

    Approach Best/Easiest/Fastest for Surgeon

    (Enlarge Slide)
  • 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.

  • Approach Best/Easiest/Fastest for Surgeon

    Slide 10.

    Approach Best/Easiest/Fastest for Surgeon

    (Enlarge Slide)

Studies on Satisfaction Tell the Story

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

  • TKA in Elderly -- Internists View

    Slide 11.

    TKA in Elderly -- Internists View

    (Enlarge Slide)
  • And one-third of patients said they were dissatisfied with their operation.

  • TKA in Elderly -- Internists View

    Slide 12.

    TKA in Elderly -- Internists View

    (Enlarge Slide)
  • 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.

  • 10-Yr Outcome of TKA Results From Arthroplasty Registry -- 4677 TKA

    Slide 13.

    10-Yr Outcome of TKA Results From Arthroplasty Registry -- 4677 TKA

    (Enlarge Slide)
  • And his conclusion was the results of knee arthroplasty in general settings don't match published series.

  • 10-Yr Outcome of TKA Results From Arthroplasty Registry -- 4677 TKA

    Slide 14.

    10-Yr Outcome of TKA Results From Arthroplasty Registry -- 4677 TKA

    (Enlarge Slide)
  • 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.

  • Patient Concerns Prior to Undergoing THA and TKA

    Slide 15.

    Patient Concerns Prior to Undergoing THA and TKA

    (Enlarge Slide)
  • 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.

  • Patient Satisfaction Post TKA

    Slide 16.

    Patient Satisfaction Post TKA

    (Enlarge Slide)

Functional Limits With Total Knee Arthroplasty

  • 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.

  • Limits of Total Knee Arthroplasty

    Slide 17.

    Limits of Total Knee Arthroplasty

    (Enlarge Slide)
  • And how many patients can kneel, squat, do all their functional activities?

  • Limits of Total Knee Arthroplasty

    Slide 18.

    Limits of Total Knee Arthroplasty

    (Enlarge Slide)
  • 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.

  • Slide 19.

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

  • Slide 20.

    (Enlarge Slide)

Knee Strength and Function With Total Knee Arthroplasty

  • 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.

  • Traditional TKA

    Slide 21.

    Traditional TKA

    (Enlarge Slide)
  • 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.

  • Traditional TKA

    Slide 22.

    Traditional TKA

    (Enlarge Slide)
  • 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.

  • Improved Extensor Mechanism Function With the Scorpio Total Knee Replacement

    Slide 23.

    Improved Extensor Mechanism Function With the Scorpio Total Knee Replacement

    (Enlarge Slide)
  • 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.

  • Improved Extensor Mechanism Function With the Scorpio Total Knee Replacement

    Slide 24.

    Improved Extensor Mechanism Function With the Scorpio Total Knee Replacement

    (Enlarge Slide)
  • 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.

  • DW -- 68 Y/O WM -- 5'9", 242 lbs: 3 Weeks Post-Op

    Slide 25.

    DW -- 68 Y/O WM -- 5'9", 242 lbs: 3 Weeks Post-Op

    (Enlarge Slide)

Marketing Issues: The "Total Knee Market"

  • 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.

  • Slide 26.

    (Enlarge Slide)
  • 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.

  • Knee Arthroplasty vs Market

    Slide 27.

    Knee Arthroplasty vs Market

    (Enlarge Slide)

Recovery Issues

  • 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.

  • MIS-UCA: Rapid Recovery Post UCA

    Slide 28.

    MIS-UCA: Rapid Recovery Post UCA

    (Enlarge Slide)
  • 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.

  • MIS-UCA: Rapid Recovery Post UCA

    Slide 29.

    MIS-UCA: Rapid Recovery Post UCA

    (Enlarge Slide)
  • 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?

  • MIS-UCA: Rapid Recovery Post UCA

    Slide 30.

    MIS-UCA: Rapid Recovery Post UCA

    (Enlarge Slide)

A Patient-Driven Market

  • 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.

  • Patient Driven

    Slide 31.

    Patient Driven

    (Enlarge Slide)
  • 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.

  • Patients -- Demanding MIS Techniques

    Slide 32.

    Patients -- Demanding MIS Techniques

    (Enlarge Slide)

Challenges in the Transition to Minimally Invasive Surgery

  • 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.

  • Slide 33.

    (Enlarge Slide)
  • The position of that large femoral component, especially this tibial keel, can be a real difficult problem.

  • Slide 34.

    (Enlarge Slide)
  • 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.

  • Skin Incision

    Slide 35.

    Skin Incision

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

  • Skin Incision

    Slide 36.

    Skin Incision

    (Enlarge Slide)
  • 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.

  • Downsized Soft Tissue Friendly Instruments

    Slide 37.

    Downsized Soft Tissue Friendly Instruments

    (Enlarge Slide)
  • So start like this, get used to the instruments with your standard technique, and then progressively downsize.

  • Downsized Soft Tissue Friendly Instruments

    Slide 38.

    Downsized Soft Tissue Friendly Instruments

    (Enlarge Slide)

Approaches for Minimally Invasive Knee Arthroplasty

  • 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.

  • Approaches

    Slide 39.

    Approaches

    (Enlarge Slide)
  • 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.

  • Approaches

    Slide 40.

    Approaches

    (Enlarge Slide)
  • 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.

  • Slide 41.

    (Enlarge Slide)
  • 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.

  • Similar Features

    Slide 42.

    Similar Features

    (Enlarge Slide)
  • We've used a number of different techniques -- median parapatellar, midvastus, subvastus in preselected patients.

  • MIS Techniques I Have Utilized

    Slide 43.

    MIS Techniques I Have Utilized

    (Enlarge Slide)
  • 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.

  • MIS Techniques I Have Utilized

    Slide 44.

    MIS Techniques I Have Utilized

    (Enlarge Slide)

Visuals on Various Approaches

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

  • Slide 46.

    (Enlarge Slide)
  • This is a subvastus approach with your exposure; this would be a subvastus with navigation, just some quick views.

  • Subvastus With Navigation

    Slide 47.

    Subvastus With Navigation

    (Enlarge Slide)
  • And here's a direct lateral approach, which we'll spend a little more time on later.

  • Lateral Approach With Navigation

    Slide 48.

    Lateral Approach With Navigation

    (Enlarge Slide)

Additional Approaches

  • 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.

  • Rationale for Midvastus: Extensile Approach

    Slide 49.

    Rationale for Midvastus: Extensile Approach

    (Enlarge Slide)
  • 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.

  • Rationale for Midvastas: Extensile Approach

    Slide 50.

    Rationale for Midvastas: Extensile Approach

    (Enlarge Slide)
  • 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.

  • Mobile Skin Window: Tissue Envelope Approach

    Slide 51.

    Mobile Skin Window: Tissue Envelope Approach

    (Enlarge Slide)
  • 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.

  • Mobile Skin Window: Tissue Envelope Approach

    Slide 52.

    Mobile Skin Window: Tissue Envelope Approach

    (Enlarge Slide)

Surgical Vignettes

  • 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.

  • VMO Exposure

    Slide 53.

    VMO Exposure

    (Enlarge Slide)
  • 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.

  • Patella Mobilization

    Slide 54.

    Patella Mobilization

    (Enlarge Slide)
  • 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.

  • Femoral Rotation

    Slide 55.

    Femoral Rotation

    (Enlarge Slide)
  • 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.

  • Distal Femoral Cut

    Slide 56.

    Distal Femoral Cut

    (Enlarge Slide)
  • 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.

  • 4 in 1 Femoral Cuts

    Slide 57.

    4 in 1 Femoral Cuts

    (Enlarge Slide)

Surgical Vignettes 2

  • 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.

  • Tibial Keel Cut

    Slide 58.

    Tibial Keel Cut

    (Enlarge Slide)
  • 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.

  • Femoral Cement

    Slide 59.

    Femoral Cement

    (Enlarge Slide)
  • 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.

  • Knee -- ROM/Stability

    Slide 60.

    Knee -- ROM/Stability

    (Enlarge Slide)
  • 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.

  • D.M. 72 Y/O Recovery Room X-rays

    Slide 61.

    D.M. 72 Y/O Recovery Room X-rays

    (Enlarge Slide)
  • 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.

  • Slide 62.

    (Enlarge Slide)
  • 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.

  • M.W. 65 Y/O WM -- 6'4" 250 lbs: Simultaneous Bilateral MIS TKA 4 Wks Post-Op

    Slide 63.

    M.W. 65 Y/O WM -- 6'4" 250 lbs: Simultaneous Bilateral MIS TKA 4 Wks Post-Op

    (Enlarge Slide)

Literature Review

  • 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.

  • Slide 65.

    (Enlarge Slide)

Study Findings of Minimally Invasive vs Standard Approach

  • 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.

  • Slide 66.

    (Enlarge Slide)
  • 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.

  • Overall Study Results

    Slide 67.

    Overall Study Results

    (Enlarge Slide)
  • Knee Society scores averaged 95.8, pretty reasonable for these patients on the pain side.

  • Overall Clinic Results

    Slide 68.

    Overall Clinic Results

    (Enlarge Slide)
  • On the functional side, 92.6. Here are our functional scores.

  • Overall Clinic Results

    Slide 69.

    Overall Clinic Results

    (Enlarge Slide)
  • 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.

  • Overall Radiographic Results

    Slide 70.

    Overall Radiographic Results

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Study Findings of Minimally Invasive vs Standard Approach (cont'd)

  • 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.

  • 2- to 4-Yr Follow-up: 216 TKA

    Slide 71.

    2- to 4-Yr Follow-up: 216 TKA

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  • 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.

  • 2- to 4-Yr Follow-up: 216 TKA

    Slide 72.

    2- to 4-Yr Follow-up: 216 TKA

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  • 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.

  • Subgroup - Std vs MIS TKA -- Min 1-Yr F/U (1-5)

    Slide 73.

    Subgroup - Std vs MIS TKA -- Min 1-Yr F/U (1-5)

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  • 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.

  • Subgroup - Std vs MIS TKA -- Min 1-Yr F/U (1-5)

    Slide 74.

    Subgroup - Std vs MIS TKA -- Min 1-Yr F/U (1-5)

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Limited-Approach Total Knee Arthroplasty: A Comparison Study

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

  • Limited-Approach Total Knee Arthroplasty: A Comparison Study

    Slide 75.

    Limited-Approach Total Knee Arthroplasty: A Comparison Study

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  • 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.

  • Results

    Slide 76.

    Results

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  • 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.

  • Results

    Slide 77.

    Results

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Suspended Leg Study Findings

  • 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.

  • Suspended Leg

    Slide 78.

    Suspended Leg

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

  • Suspended Leg

    Slide 79.

    Suspended Leg

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  • Knee Society scores were pretty good with the suspended leg.

  • Knee Society Scores

    Slide 80.

    Knee Society Scores

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  • Functional recovery mirrored the same type of results.

  • Post-Op Rehabilitation

    Slide 81.

    Post-Op Rehabilitation

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Should We Perform Minimally Invasive Surgery?

  • 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.

  • Pitfalls and Complications

    Slide 82.

    Pitfalls and Complications

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  • 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?

  • Pitfalls and Complications

    Slide 83.

    Pitfalls and Complications

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

  • Why Should We Do MIS TKA?

    Slide 84.

    Why Should We Do MIS TKA?

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  • 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.

  • Why Should We Do MIS TKA?

    Slide 85.

    Why Should We Do MIS TKA?

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  • 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.

  • Slide 86.

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Additional Study Findings on Minimally Invasive Surgery

  • 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.

  • Slide 87.

    (Enlarge Slide)
  • But if you look, his range of motion is better; Knee Society scores were a little better.

  • Mini Midvastus vs Std TKA

    Slide 88.

    Mini Midvastus vs Std TKA

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

  • Mini Midvastus

    Slide 89.

    Mini Midvastus

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  • 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.

  • Mini Midvastus

    Slide 90.

    Mini Midvastus

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A Word of Caution: Rapid Discharge and Steroid Use With Minimally Invasive Surgery

  • 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.

  • Risk of Rapid Discharge

    Slide 91.

    Risk of Rapid Discharge

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  • 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.

  • Rapid Discharge

    Slide 92.

    Rapid Discharge

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

  • Rapid Discharge

    Slide 93.

    Rapid Discharge

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  • 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.

  • Arthroscopy and Intra-articular Steroids

    Slide 94.

    Arthroscopy and Intra-articular Steroids

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Additional Approaches

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

  • MIS Navigated Lateral Approach

    Slide 95.

    MIS Navigated Lateral Approach

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  • 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.

  • Slide 96.

    (Enlarge Slide)
  • Possibly arthroscopic-assisted using it as a light source and for magnification.

  • Arthroscopic TKA -- ???

    Slide 97.

    Arthroscopic TKA -- ???

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

  • Slide 98.

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  • 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.

  • Evolution vs Revolution

    Slide 99.

    Evolution vs Revolution

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

  • Slide 100.

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  • 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.

  • L.C. -- 4 Wks Post-Op Bilateral TKA

    Slide 101.

    L.C. -- 4 Wks Post-Op Bilateral TKA

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  • 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.

  • Not All Techniques Same

    Slide 102.

    Not All Techniques Same

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  • 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.

  • Summary

    Slide 103.

    Summary

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