People with osteoarthritis who need a knee replacement may do just as well—or even better—with a partial replacement than a total replacement, according to a study published in The Lancet.
The large U.K. randomized clinical trial compared outcomes of 538 people (average age 65) who underwent knee replacements for osteoarthritis of the knee’s medial compartment—one of three compartments that make up the knee and typically the compartment most severely affected in osteoarthritis. Half of the individuals had a partial knee replacement, which involved replacing only the affected compartment. The other half had a total knee replacement in which the damaged compartment as well as the other two compartments were replaced.
The researchers observed participants for five years after their procedures. They found that partial replacement had a slight edge over total replacement when it came to overall lower health care costs; less pain; fewer complications, such as knee pain and stiffness; and faster recovery.
A total knee replacement is commonly used for single-compartment arthritis because it’s thought that a partial replacement is more likely to require a re-operation, which can include a revision to replace the original implant as a result of a shorter device lifespan, infection, or persistent pain. However, this study suggests the rates of re-operation for both total and partial replacements are about the same after five years. Currently, only about 10 percent of knee replacements performed in the United States are partial.
What you should do
Both partial and total knee replacements have their own benefits and risks, and partial knee replacement may not be suitable for some patterns of osteoarthritis, nor is it used for rheumatoid arthritis. If you’re facing a future knee replacement, have a discussion with your orthopedist about the pros and cons for each procedure. And, regardless of the type of procedure you choose, it’s best to have a surgeon who performs many of these types of surgeries and at a hospital with a high volume of knee replacements.
This article first appeared in the January 2020 issue of UC Berkeley Health After 50.