Can You Have Both Knees Replaced at the Same Time?

Most patients who need a knee replacement only need one knee replaced. But arthritis frequently affects both knees — and when both become painful and start limiting walking, exercise, travel, and daily life, it's natural to wonder whether you should simply have both replaced at once.

The short answer is yes. The better question is whether you should.

What is bilateral knee replacement?

A bilateral knee replacement means both knee joints are replaced, rather than just one. There are two ways to do it:

Staged bilateral knee replacement

Two separate knee replacement surgeries performed a few weeks apart. This is the approach I recommend for nearly all patients.

Simultaneous bilateral knee replacement

Both knees replaced during the same operation, under a single anesthetic. This can be appropriate for select patients, but it's not the approach I recommend for most people.

My recommendation: stage the knees

For the overwhelming majority of patients, I recommend replacing one knee first and then replacing the second about 4–6 weeks later. This recommendation is based on safety and recovery — not convenience.

When we stage the surgeries, your body only has to recover from one knee replacement at a time. Once the first knee is functioning well, it becomes an asset during recovery from the second.

Why staging is safer

There are several real advantages to staging the surgeries.

Lower blood loss

Knee replacement involves blood loss. When both knees are replaced simultaneously, the total blood loss is substantially greater. Staging divides that blood loss between two separate operations, reducing the likelihood of significant anemia.

Lower transfusion rates

Patients undergoing simultaneous bilateral knee replacement have higher transfusion rates than patients who stage their procedures. Reducing transfusion risk is one of the major reasons I generally recommend staging.

Shorter operations

Replacing two knees in one surgery requires significantly longer anesthesia time. Two shorter surgeries are generally easier on the body than one prolonged operation.

Easier early recovery

This is perhaps the most important reason. After a knee replacement, you rely heavily on your non-operated leg during the first few weeks. When both knees are replaced at once:

• Both knees hurt
• Both knees are swollen
• Both knees are stiff
• Both legs are recovering at the same time

You lose the advantage of a stronger leg to support walking, transfers, stairs, and daily activities. When surgeries are staged, one knee is already improving before the second surgery happens.

More focused rehabilitation

Physical therapy can concentrate on a single knee during the most critical period of recovery, which often makes rehabilitation more comfortable and more efficient.

How far apart should knee replacements be?

I typically recommend scheduling the second knee about 4–6 weeks after the first. That allows enough time for:

At the same time, it's short enough that both knees can be replaced within a relatively brief overall recovery period. For patients with severe arthritis in both knees, this timeline often represents the best balance between safety and efficiency. You can see what each recovery looks like in the knee replacement recovery timeline.

What about replacing both knees at once?

Simultaneous bilateral knee replacement isn't wrong. In carefully selected patients, it can be a reasonable option. Those patients are typically:

Even in these patients, though, there are tradeoffs. Potential downsides include:

• Higher blood loss
• Higher transfusion rates
• Longer anesthesia exposure
• Greater physiologic stress
• More difficult early rehabilitation
• No “good” leg available during recovery

For those reasons, simultaneous bilateral knee replacement remains the exception rather than the rule in my practice.

Recovery after staged bilateral knee replacement

Most patients find staged surgery easier than they expected. The first knee replacement follows the same pathway as any standard knee replacement:

By the time the second knee replacement occurs several weeks later, the first knee is already helping support daily activities — and many patients actually feel more confident the second time, because they already know what to expect. Curious how same-day surgery works? See outpatient (same-day) joint replacement.

What patients commonly tell me

Patients with arthritis in both knees often say:

Those are all understandable. But the reality is that doing both knees at once often creates one very difficult recovery, while staging creates two much easier recoveries. The finish line is the same — the path to get there is usually smoother with staged surgery.

From Dr. Harb: how I approach bilateral knee arthritis

When a patient comes to see me with severe arthritis in both knees, I start with a simple question: what is the safest and most effective way to get this patient back to the life they want? For most people, the answer is a staged approach.

As a fellowship-trained hip and knee replacement surgeon, my goal isn't simply to replace the joints — it's to optimize the entire recovery. Replacing one knee, letting it recover, and then replacing the second about 4–6 weeks later gives patients the best balance of safety, comfort, and long-term outcomes.

If arthritis in both knees is limiting your life, schedule a consultation with Dr. Harb to talk through whether one knee, or a staged plan for both, is right for you — and what knee replacement recovery would look like.