What is a partial knee replacement?
The knee consists of three “compartments.”
1. There is the medial compartment on the inside of the knee
2. The lateral compartment on the outside of the knee
3. The compartment under the kneecap
All three of these compartments are replaced in a traditional knee replacement. A partial knee
replacement only replaces the medial compartment.
What are the benefits of a partial knee replacement?
In general people tend to recover faster from a partial knee replacement. In fact, most people leave the same day as surgery and are back to their regular routine in weeks. The surgery has less pain, easier recovery and feels like a “more natural” knee. Since all of the ligaments are kept with a partial knee replacement, the natural feeling of a partial knee replacement tends to leave patients highly satisfied.
How do I know if I am a candidate for the surgery?
There are several qualifications that patients must meet to be eligible for this surgery.
1. First you have to have arthritis only on the inside of the knee. If you have arthritis all over the knee, the partial knee will not relieve all your pain.
2. Not only does the partial knee keep the natural knee ligaments including the ACL and PCL, but it also requires that they be present for stability. So if your ligaments are incompetent, you cannot get a partial knee replacement.
3. You must have good range of motion and minimal deformity. If your knee is stiff and crooked, a partial knee cannot correct this and will fail early.
What else should I know?
If you are interested in a partial knee replacement special X-rays can be taken in the office to give a better understanding of your knee. When electing for a partial knee replacement it is important to understand that the final decision for or against a partial knee must be made during surgery. There are many things that can only be seen once the knee is open in surgery. If during surgery you are found to not be a candidate for a partial knee replacement, you will instead get a traditional total knee replacement. While having to switch from partial to total knee surgery is a rare occurrence, you need to understand it is a possibility and a decision during surgery will be made to maximize your outcome.
What happens when the partial knee “wears out”?
Much like a total knee replacement, a partial knee replacement doesn’t last forever. In younger patients, I hope for 10-15 years of survivorship. In older patients, a partial knee replacement may last the rest of her life. However, when a partial knee fails, either due to advancing arthritis in the rest of the knee or loosening of the implant, revision surgery is required. The same thing happens after a total knee. No knee replacement, be a total or partial will last forever. However, a revision total knee after a partial knee replacement is much easier to perform, and patients tend to be a little happier with the result than a revision after a total knee.