Knee
iTotal Knee
Jul,29,2011 13:50 Filed in: Total Knee Replacement | Computer Navigation
Conformis has been working on a CT guided, custom knee replacement for a number of years now, using the same technology we are using for their uni knee replacement. Unlike other systems, this is a true custom knee unique to each patient. it should allow a more accurate knee without giving up the benefits of a total knee replacement. We should be able to start our first cases in the fall. I’m really looking forward to offering this to our knee arthritis patients.
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Bilateral Total Knee Replacement
Jan,27,2011 21:52 Filed in: Knee Replacement
I get a lot of questions about bilateral, or both at the same time, knee replacement. Doctors have really struggled with this concept because doing both at the same time can result in a much more difficult operation. It obviously takes twice as long, can result in more blood loss, more stress on the heart and lungs, and a longer anesthetic. Doing both knees together takes some surgeons three to four hours and can get very tiring. Because of these added complications, many surgeons severely limit the number of bilateral knee replacements they will do - if they will do any at all.
At the Rubin Institute, we have been able to minimize these problems by combining several techniques. The first is the computer navigation I discussed in an earlier post. By doing all the calculations using custom molds before the surgery, we can speed up the measuring process for both knees. Combining this with some innovative, uncemented knee technology, we can eliminate cementing, which can take 15 - 30 minutes per side. These techniques, I believe, have resulted in better alignment and a much quicker procedure. We are able to do both knees in about 90 minutes with a spinal anesthesia, which is generally safer for the patient.
Our early data show better results, in less time, with fewer complications. It’s allowed me to open up this procedure to far more patients than in the past because of the reduction in risk. While doing both knees at the same time does result in more time in the hospital, many patients recover just as quickly from two knees as one. I always caution that this is still major surgery, and can certainly have complications, but it is a much more reasonable option than it was in the past and can benefit a lot of patients.
At the Rubin Institute, we have been able to minimize these problems by combining several techniques. The first is the computer navigation I discussed in an earlier post. By doing all the calculations using custom molds before the surgery, we can speed up the measuring process for both knees. Combining this with some innovative, uncemented knee technology, we can eliminate cementing, which can take 15 - 30 minutes per side. These techniques, I believe, have resulted in better alignment and a much quicker procedure. We are able to do both knees in about 90 minutes with a spinal anesthesia, which is generally safer for the patient.
Our early data show better results, in less time, with fewer complications. It’s allowed me to open up this procedure to far more patients than in the past because of the reduction in risk. While doing both knees at the same time does result in more time in the hospital, many patients recover just as quickly from two knees as one. I always caution that this is still major surgery, and can certainly have complications, but it is a much more reasonable option than it was in the past and can benefit a lot of patients.
Computer Knee Navigation
Jan,25,2010 12:17 Filed in: Knee Replacement
I’ve always been very skeptical of computer navigation in total knee replacement. While it makes sense that computers in the OR could help us place the parts more accurately, in practice, these systems have been cumbersome, time consuming, and haven’t been shown to produce any improvement in outcomes. The extra equipment is very expensive and required additional pins to be put into patients bones to guide the computer.
I’ve recently started using a system that produces custom molds made from an MRI scan of the knee. The molds are made before the surgery and guide the placement of the knee replacement. The molds are extremely accurate, require less time than a standard total knee and also allow us to place less instruments in the knee - not more. While the MRI and the molds are expensive, we do see some cost savings in less time in the OR and less instruments that need to be sterilized. The benefit to the patient is a custom fitted knee and less time in the OR. Not every patient is a candidate, and some insurers are resisting paying for the molds, I think this new procedure is going to be very helpful.
More Knee Resurfacing
One of the big advantages of this procedure is the recovery time. Most of our patients are able to walk without a cane in just a few days and return to driving and exercising in about a week. It’s been so impressive, that I often have to get people to slow down, because they are feeling so much better. It’s really a dramatic difference from a total knee replacement. The xray to the left shows how small this implant is.
Knee Resufacing Update
I think this procedure will be a major improvement for a number of our patients. It can be done athroscopically with a small incision for the femoral (thing bone) component which allows most patients to go home the same day. Pain is much less than with a total knee replacement and the physical therapy is much easier. The parts are so small that, if a patient needs a total knee replacement someday, they will not interfere. Not everyone is a candidate, but I think this procedure will spare a lot of people from a premature knee replacement
Arthrosurface
I very excited about a new technology that we now have access too. Called Arthrosurface, it’s an innovative new approach to knee arthritis. Using an arthroscopicly assisted technique, we can resurface small parts of the knee that are worn our for arthritis. This is a much smaller operation than a knee replacement, and patients can go home the same day and walk on the knee immediately. Physical therapy is much easier and the time investment is much less. Not everyone is a good candidate for this new procedure, but I think it will save many patients from a much larger operation. We don’t know the long term outcomes yet, but I’m very optimistic about this technique’s future.
Gender Knee Update
Jun,16,2008 07:50 Filed in: Knee | Knee Replacement
I still get quite a few women asking about gender specific knees. Most of them have seen television ads or a web site promoted by an implant manufacturer. I think one of the issues that has gotten lost amid all the hype is the wide variarions that occur normally in human knees. Knees vary not just by gender, but by age, race, height, weight and the type of arthritis that the patient is suffering from. Sometimes a “male” knee is better for a woman or vice versa depending on the size of the patients knee.
The most imporatant thing to focus on is the number of sizes available and picking the right knee for each patient. I try to pick the knee that is most appropriate for a specific problem, and then use the wide variety of differnent sized to get a perfect fit. In my experience, focusing on just the patient’s gender is too much of an oversimplification.
The most imporatant thing to focus on is the number of sizes available and picking the right knee for each patient. I try to pick the knee that is most appropriate for a specific problem, and then use the wide variety of differnent sized to get a perfect fit. In my experience, focusing on just the patient’s gender is too much of an oversimplification.
Gender Specific Knees
I've had some questions recently about Zimmer's gender specific knee, which is targeted at female patients. I am actually pretty upset about what is a blatant attempt to market unproven designs directly to patients. It is true that femaie knees are generally smaller and have a slightly different groove for the knee cap than men do. However, most implants already take this into account and have for years. There is no reason to label a knee "specific to women" other than to steer them to a Zimmer implant. I believe that my patients are smarter than that and will see through what is basically marketing hype. Unfortunately, we often spend a lot of time talking about non-issues like gender specifics rather than important things, like getting through the surgery in the safest and smoothest fashion possible.
Deuce Knee Implant
May,15,2008 08:39 Filed in: Knee | Knee Replacement
We have a new knee implant available for patients with arthritis of the knee. It's called the Deuce because it replaces the inside of the knee and knee cap only. 
The implant can be put in with a minimally invasive technique and retains all the knee ligaments, which isn't possible with traditional total knee replacements. The thigh bone side of the implant is made of a ceramic, called Oxinium which may not wear out as fast as standard metal implants. I think it may be a good choice for younger patients who want to remain active. We can determine if this is an appropriate choice by examining x-rays and the arthritic knee.