What is a unicompartmental (partial) knee replacement?

As we wear out our knee, we do not necessarily wear out the entire knee.  In fact, most patients begin by wearing out the medial (inside) compartment of the knee.  The knee is comprised of three compartments: the medial (inside) compartment, the lateral (outside) compartment, and the patellofemoral compartment (the area where the knee cap (patella) and femur (thigh bone) come together.  As previously said, the medial compartment is the most common compartment to wear out first.  Sometimes only the lateral or patellofemoral compartments wear out as well. If only one compartment is worn out, then there is the possibility of a unicompartmental, or partial, knee replacement.  This procedure, performed with the custom cutting blocks in my practice, is less invasive and leaves you with more of your own anatomy.  This can lead to more rapid recovery and a more normal feeling knee.

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When should I have a unicompartmental (partial) knee replacement?

Similar to total hip and knee replacement, the decision to have partial knee replacement is made with input from Dr. Waddell and you, the patient. When you have tried all non-operative treatments and these have failed and when you meet the criteria for the surgery, Dr. Waddell will offer you the surgery.  You will ultimately decide when to have the surgery.  Dr. Waddell likes to tell you that the decision should be made to have surgery when you have tried nonoperative therapy, you are limited in your ability to perform activities you need to perform, and the bad days outnumber the good days with the pain. 

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What can I expect after my unicompartmental (partial) knee replacement?

Most patients stay in the hospital about 3-5 hours after their partial knee replacement.  Patients will walk, just like in total hip or total knee replacement, right after surgery. You will go home and begin outpatient therapy within 1-3 days. 

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Most patients begin feeling better within a few weeks. You will almost certainly be able to return to full activity after the partial replacement. Some patients do this very soon after surgery, and some patients take a little longer.

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How long will my unicompartmental (partial) knee replacement last?

Based on current data from research studies, partial knee replacements are expected to last 10-20 years.  The data has shown that the more accurately the implant is placed, the longer it will survive.  Dr. Waddell uses robotic-assistance to place his partial knee replacements.  Using this technology, the accuracy in placing the implants is over 99%.  With the implant in the best possible spot, Dr. Waddell expects the replacement will last as long as possible and improve function and comfort for the patient.