Knee Replacement

Computer Knee Navigation

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.

Signature™ Personalized Patient Care*

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.

|

German Surgeon Visit

We often have visitiors from around the world at the Rubin Institure. Recently, I had a group visit from Germany to observe hip and knee replacement. They were very interested in minimally invasive surgery and pain management techniques. They also got to see a minimally invasive hip replacement, revision knee replacement and a hip resurfacing. I always have a great time showing off what we are able to accomplish at the Rubin Institure, but I also get to learn a lot myself. Out visitors never fail to teach me some technique I wasn't aware of or propose some improvement we can make. it's this kind of interaction that forces me to always try to stay ahead of our very knowledgable and experienced visitors.
|

Progressive Knee Replacement

Now that we have so many options for treatment of knee arthritis, I’ve been trying to formalize an algorithm for progressive replacement of the knee. I recently gave grand rounds at Howard University on this idea. While total knee replacement is a wonderful operation that works very well, it does take a long time to recover from. A great many patients can benefit from replacing just the part of the knee that is worn out and not the whole thing. These patients have a faster recovery, less pain, and more natural feeling knees.
While this concept has been working very well for my patients, it’s extremely important to pick the right operation for the right patients, otherwise, they may continue to have pain. This algorithm helps to insure that treatment is as optimal as possible for each person no matter what their age, race or gender may be.
|

Parital Knee Replacement Around the World

globe.png

I recently had the opportunity to give lectures in Fukuoka Japan, and Vienna Austria on partial and full knee replacements. It was a wonderful experience to go to prestigious international meetings on almost opposite sides of the world. I found it most interesting that the attitudes toward partial knee replacement are very different in these very different countries. In Japan, surgeons tend to be fairly conservative. They favor osteotomies or realignment of the bones in younger patients who have partially arthritic knees. In Europe, surgeons are much more in favor of partial knee replacement, because of the quicker and more predictable recovery.My talk on partial knees was very well received in Vienna, while it took much more explaining and convincing in Japan. I think it’s very healthy for surgeons to have different opinions and attitudes about implants and operations. It encourages us to constantly examine what we are doing and make sure we know exactly why we are recommending different treatments for different patients. I always try to customize each patient’s treatment and not just recommend the same total knee replacement for every patient with arthritis. It’s nice to know that there are so many surgeons around the world who have the same attitude.
|

Trip to Japan

I am very excited to have been invited to speak at the Japanese Orthopaedic Association Annual Meeting in May. I’m going to be speaking on total knee replacement and partial knee replacement in younger patients. Hopefully, I’ll be able to post some pictures when I get back.
|

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

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.
|

Deuce Knee Implant

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.
page2_blog_entry11_1
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.

|

Knee Tourniquet

When a patient undergoes a knee replacement surgeons almost always use a tourniquet around the thigh to cut down on blood loss and make it easier to see during the surgery.  The tourniquet is inflated to a pressure of 250 to 350 mmHG, which cuts off all blood flow to the leg and foot. As you can imagine, this puts tremendous pressure on the thigh muscles.  I've long suspected that a lot of the pain and swelling after surgery is related to the use of a tourniquet. So, over the last year, we have been conducting a formal study of patients who undergo knee replacement without a tourniquet.
 
What I have found is that when a tourniquet is not used, patients have less pain, less blood loss, better range of motion and less swelling.  The really dramatic difference is when patients return to the office, six weeks after the surgery, they are much more comfortable and much less swollen. It is now our standard form of treatment for both primary and revision surgery due to it's success.
 
There have been many studies published by The Journal of Bone and Joint Surgery that agree with these findings and I think a lot of surgeons haven't changed just because they are comfortable with the tourniquet.  I plan to publish the findings formally fairly soon.
 
****Just to clarify, a tourniquet is placed on all knee replacement patients, it is just not inflated when there is adequate blood control.
|

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.
|

Knee Implants

How do I choose an implant? What are all these ads on TV about woman's knees? See our new article under the Knee Replacement link for more info!
|

3D Knee

We are currently conducting a study of the 3D Knee. It's an interesting concept that should work well for younger patients who need a total knee replacement. By changing the shape of the surface that the patient walks on, the implant can compensate for the ACL, which has to be removed during total knee surgery. This should provide better stability and a more natural knee for very active patients.
|