What is the difference between a partial and total knee replacement: Which one is right for me?
One of the most common questions that I get asked is “What is the difference between a partial and a total knee replacement, and am I a candidate for one or the other?”
There is a second question that you must ask with this question which most patients don’t know to ask, and that is “Do you perform both operations?” Because if the answer to this question is “no” then your surgeon may not be offering you the operation that is best for you.
As with almost every question in orthopedics, it is important to understand some anatomy before the question can be answered. Although the knee is one joint composed of three bones, the femur (thigh bone), tibia (shin bone), and patella (knee cap), it is actually made of three distinct compartments. The three compartments are the medial (inside), lateral (outside) and patellofemoral (underneath the knee cap).
One more important piece of information that you need to know when discussing partial and total knee replacements is the definition of arthritis. Most people think that arthritis is something in the knee that we take out. In fact, it is just the opposite, arthritis is the generalized wearing away of the cartilage which acts as the cushioning in our joints. The most common type of arthritis is osteoarthritis, which occurs due to generalized wear and tear. Two other types of arthritis are post-traumatic arthritis, which is an injury to cartilage due to a traumatic event or distinct injury such as a broken bone, and inflammatory arthritis where the body’s own immune system mistakenly attacks its own joints.
So, back to our question, “What is the difference between a partial and a total knee replacement, and am I a candidate for one or the other?”
With our new knowledge, the answer becomes simple….
If you have arthritis that effects predominantly one compartment (see picture on the right below) of the knee that causes pain in that area and it does not response to conservative treatment (like rest, ice, medications, and injections), then you would be a candidate for a partial knee replacement, which selectively resurfaces only one compartment of the knee.
If you have arthritis that effects two or three compartments of the knee (see picture on the left above) and have not responded to conservative treatment, then a total knee replacement, which resurfaces all three compartments, is likely a better option.
A partial knee replacement is generally a smaller operation than a total knee replacement and has a slightly faster recovery and generally lower risks of complications such as infection and blood clots (although the risks for total knee replacement are generally quite low as well). The one major drawback to partial knee replacements when compared to total knee replacement is the risk of the non-resurfaced compartments wearing out. Since a total knee replacement resurfaces all compartments, this risk is not associated with total knee replacements. If a patient has a partial knee replacement and the other compartments wear out over time, then he or she would require another operation to convert the partial knee replacement into a total knee replacement (easier said than done).
Ultimately the goal of both surgeries is the same, to get rid of pain and return to back to being able to do the things that you weren’t able to do due to pain in your knee. Talk to your surgeon about which operation is the best choice for you. I am proud to offer both procedures to our patients.
Call today at 914-631-7777 to schedule an appointment and find out which procedure is right for you.