Innovations in Knee Surgery: Q&A on Simultaneous Bilateral Knee Replacements

Published May 23, 2017

It’s not unusual for patients with two bad knees to require a joint replacement for each knee. But what if you don’t want to go through two separate knee replacement surgeries?

You may not have to. Simultaneous bilateral knee replacement, a technique that has been around since the 1990s but has slowly risen in popularity, allows healthy patients to undergo a tandem operation. Two teams of doctors perform a knee replacement at the same time, which limits the amount of time a patient is in the hospital, their anesthetic exposure, and the recovery process in addition to the cost.

Today, more than 700,000 knee replacements are performed each year in the U.S., according to The Centers for Disease Control and Prevention. Although simultaneous knee replacement isn’t a fit for all patients – you have to be healthy enough to withstand the double surgery without increased risk of complications, and motivated enough to work through the extra pain – it can be the right option for many patients who need both knees replaced. We asked Dr. M. Brian Polsky, a sports medicine surgeon in the Orthopaedic Associates of Central Maryland care center, what patients need to know when considering the procedure.

What is the biggest advantage to performing the knee replacements simultaneously?

There’s both a clinical and a practical benefit to this approach. From the clinical perspective, when the knees are replaced at literally the same time, you only need one anesthetic exposure. This is an advantage, because research suggests that long or frequent exposures to anesthetics can make some patients sicker, possibly leading to a longer recovery or more complications. As physicians, our goal is always to make both the surgery and recovery process as smooth as possible.

The practical benefit is simply that you only have to experience the surgery and recovery process once. Once the surgery is complete, you can start recovering immediately and don’t have to worry about scheduling the second surgery and following rounds of physical therapy. It’s especially convenient for patients concerned about scheduling time off of work for two surgeries. 

What should patients know when considering this surgery?

You have to be motivated. This isn’t an option for everyone, but it is a great choice for the right patient. The rehab and recovery process typically takes a little longer for simultaneous knee replacements than individual knee replacements. And there will likely be additional pain from performing both surgeries at once, although we work closely with our patients to manage all pain and discomfort. Because of this, the simultaneous surgery is a good fit for patients who are committed to the recovery process and eager to complete both knee replacements as soon as possible.

Because of the dedication required for full rehabilitation and recovery, patients also need strong social support. Before the surgery, I’ll prepare my patients and their families to make sure they are all able to commit to the recovery and physical therapy process.

Who is the ideal candidate?

Well, first – and perhaps obviously – you need to have two bad knees that should both be replaced. It’s common for patients to have one really bad knee, and one that’s not quite as bad. In that situation, I would typically do an individual knee replacement for the worst knee, because the other knee might improve after the surgery if the patient is walking better. They may be able to avoid a second knee replacement entirely.

To be a candidate for simultaneous bilateral knee replacements, you would also need clearance from your primary care doctor to ensure your heart, lungs and medical history are safe enough to tolerate the surgeries. Typically, these patients are young and active, or elderly but medically stable. Both of these groups tend to be motivated to finish the surgical and recovery process as soon as possible.

What is the recovery process for simultaneous knee replacements?

It’s very straightforward. You’ll probably be in the hospital for two or three nights after surgery, and then you’ll be cleared to go home or to a rehab facility. Then, it’s time to focus on rehabilitation. You’ll be doing exercises on both legs to stretch and strengthen the muscles, getting your strength and stamina back and learning to walk again. It’s the exact same rehabilitation process as an individual knee replacement, but you’ll of course be repeating the exercises on both legs. You will likely be fully recovered in about four months.

What has been the patient reaction to simultaneous knee replacement surgeries?

Well, I perform this surgery fairly often – about three times a month – and my patients have been very happy with their results. They don’t have any regrets about their choice. In fact, they come back and let me know that they’re glad they opted for the simultaneous surgery.

Brian Polsky, M.D., is a board certified and fellowship trained orthopaedic surgeon specializing in orthopaedic surgery, minimally invasive arthroscopic surgery, sports medicine and joint replacement at the Orthopaedic Associates of Central Maryland care center. Dr. Polsky also serves as a Clinical Instructor in the Department of Orthopaedics at the University of Maryland and regularly publishes new research in peer-reviewed medical journals.