Tad Gerlinger, MD, who specializes in joint replacement surgery at Midwest Orthopedics at Rush, talks about a different type of knee replacement surgery that is improving patient satisfaction.
So, what is the new partial knee replacement?
Dr. Gerlinger: A partial knee replacement — or unicompartmental knee replacement– is not a new surgery, actually. Dr. Jorge Galante, a founder of our practice, was one of the pioneers of this procedure and designed the initial successful prosthesis for partial knee replacement. We actually have a very good database and research to show how well his prosthesis did over a number of years. And that’s how I was exposed to it in my fellowship here 15 years ago and learned from the guys he trained. So, I was able to learn from him. But partial knee replacement is something that not everyone is exposed to. It’s replacing just a portion of the knee, the compartment that’s worn out. Because the knee has three compartments: the medial compartment, lateral compartment and the patella femoral joint. And all three of those can be replaced individually versus a total knee which replaces all three at once. The upside of the partial is that it carries a lower risk. It can be done routinely as an outpatient for most patients. Patients in my practice have a a much faster recovery. The unicompartmental knee replacement patients routinely walk in at three weeks, rarely with any assistive devices and almost never on any medication at that point. So, at three weeks they are significantly better than the day I met them which is remarkable and very rewarding.
So how would you put that?
Dr. Gerlinger: So partial knee replacement is just replacing one of the three compartments of the knee whereas a total knee replacement replaces all three compartments of the knee at the same time.
Walk me through what is done in partial knee replacement, when you get in there? Tell me the good, bad and the ugly.
Dr. Gerlinger: So, in a partial knee replacement, the incision is similar to a total knee but can be a little bit smaller. You examine all components of the knee to ensure the rest of the knee is not worn out and verify your physical exam. And then you go about replacing just that one compartment which usually requires a tibial cut, which is the lower bone, and a femoral cut to reshape the end of the femur to accept the prostheses. The patella is not touched surgically at all in the procedure because that’s usually in pretty good shape and is a requirement of getting the partial. And then you glue in the components for the partial prosthesis pand then close up the incision.
Tell me the then the benefits of a partial especially if I’m a younger patient?
Dr. Gerlinger: I think all ages do benefit from partial knee replacements. That’s one of the questions that people routinely ask: what is the advantage over a total? Again, as you said, it has to be the appropriately selected patients. The knee has to be appropriate for a partial. But being that the majority of the wear and pain is coming from a single compartment, the advantages are a quicker recovery. And it’s lower morbidity and a quicker recovery. Those are the main advantages.
Are there any disadvantages?
Dr. Gerlinger: Disadvantages … I forgot to add that actually one other large advantage of a partial knee replacement is it gives you the most normal knee that you can have. So, all modern total knee replacements, except for some newer designs that are not yet proven, require you to remove the ACL. And so, for a knee that has an intact ACL before surgery, to remove that does change the biomechanics of the knee. It changes the way the knee feels to the patient. We think that this may be responsible for some of this dissatisfaction in total near replacements. There is also good literature to show that the functional satisfaction after a partial knee replacement is higher than that of a total knee replacement. I think that given all aspects of it, if you are truly desiring function as a young person to play tennis and ski and do activities require cutting and otherwise stress of the knee, partial knee replacements are going to allow you to do those things more reliably.
So, one of the advantages of the partial is that you are able to keep the ACL?
Dr. Gerlinger: Yes ma’am.
I didn’t realize you didn’t have an ACL. So, talk about that for a second.
Dr. Gerlinger: Sure, so in a partial knee replacement surgery as compared to a total knee replacement surgery, you replace just a single compartment. A total knee requires you in almost all designs to either remove the ACL by itself or both the ACL and the PACL depending on the design of the knee. There are some newer knees that allow preservation of both. But those are still what I would consider experimental. So, the partial knee gives you the most normal knee that you can have with a replaced knee. And that’s one of greater sources of satisfaction, function, normal feel for the patients and one of the big advantages for patients that can indeed have a partial.
Candidates for a partial?
Dr. Gerlinger: Candidates for partial knee replacements are young and old. Age group doesn’t matter. The risk factors and comorbidities and things that put people at risk for complications of a total knee are the same for a partial knee. But it’s the lesser surgery, so potentially a little safer. So, young, old, active patients, the primary thing is that the symptomatic arthritis needs to be limited to one compartment of the knee.
What’s the recovery like?
Dr. Gerlinger: The recovery after partial knee is much quicker than a total. Routinely patients are walking into my office at three weeks without assistive devices. They’re better than when I met them. And they’re not taking any medication.
And then how soon can you get back to your normal activities? I guess that varies for everyone. Some people are marathon runners. Some are just wanting to walk to the grocery store. But how soon can they get back to normal do you think?
Dr. Gerlinger: I talk to patients about what they consider normal at the very beginning of our relationship and what their goals are after surgery. So, the more disabled they are by their arthritis, the longer they’ve had pain, the longer they limped, the longer they modified their activities or limited their exercise, that’s going to prolong recovery. And a younger patient who has only had significant symptoms for a year or two and hasn’t lost that much muscle mass or strength, their recovery is very quick and they can get back almost everything they want very rapidly. An older patient is potentially a little more deconditioned and depending on what they think is their normal, can take a little bit longer. So, it’s different for everyone, different based on their expectations. But it is the quickest possible recovery of any knee replacement surgery. Young, active people, I think are great. And it used to be we’ve shied away from those, for fear of the partials either wearing out or getting arthritis in the rest of the knee. Putting them in young people has always been a concern for those reasons. However, I think the recent data shows that, number one, we don’t know that a return to athletic activity or high impact activities even will decrease the longevity or how long it lasts. That data just doesn’t exist actually. So inherently you think, “oh, you have an artificial compartment. It may wear out faster with a higher activity level.” And it kind of makes sense. But actually, we’re not seeing that. And then as far as transitioning to the other compartments wearing out or maybe conversion to a total knee, that’s one of the bigger, more common questions patients ask me. The survivability of a partial knee replacement and that of a total knee replacement, meaning how long it lasts, is about the same. So, with a partial, you convert it to a total knee. The total knee though, you would have to do a full revision which is a much bigger operation with much lesser outcomes. So personally, if I could get a partial, I’d much rather have that, worry about it or being revised or a total down the road, rather than get a total near right off the bat. And one of my favorite statistics is that the data shows that 80 percent of patients who get a partial knee replacement never need another operation. So, only one in five ever need anything else done in their lifetime. You’ve got a pretty good chance of needing nothing and that being the only treatment you’ll ever need which is pretty reassuring. And that’s across age groups.
What does this surgery do for somebody’s quality of life? Maybe we can talk about Jonathan as an example?
Dr. Gerlinger: Arthroplasty in general, be it a hip, knee, partial knees, total knees, really is very good at returning quality of life. We have higher satisfaction with the partials, and I think that the partial is my most reliable way of getting, even young, active, demanding, patients back to their level of pre-injury, pre-arthritis condition so they can ski, they can run if they want, I don’t know that I recommend it, but like I said the data is not really out there to say you shouldn’t. So, I think that if that’s really what’s you’re most interested in. If that’s the activity that means the most to you and your life and your quality life, then run and we’ll deal with the situation if something arises. And I have plenty of patients that do run on the partial knees. So, I think that young patients, I enjoy working on them. I like all spectrum because you can really improve people’s quality of life. But the young people, who are more demanding and are raising kids and are working, that’s a special group and I do enjoy taking care of them. And if I can get their quality life back and prolong any disability. That’s really rewarding.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
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