Can Both Knees Be Replaced at the Same Time? Bilateral Knee Replacement Explained

The central question is not whether both knees are painful. It is whether the patient can safely tolerate the physical demands of treating and rehabilitating both knees together.

Simultaneous bilateral knee replacement

Both knees are replaced during the same surgical session and anaesthetic.

What this may mean:

• One admission and one anaesthetic
• One combined rehabilitation period
• Both legs recovering at the same time
• Greater immediate physical and medical demands

Staged bilateral knee replacement

One knee is replaced first. The second knee is operated on after a planned recovery interval.

What this may mean:

• Each operation places less immediate stress on the body
• One stronger leg may assist during the first recovery
• Two admissions and two anaesthetics
• A longer total treatment period across both surgeries

Same-day surgery may be approached more cautiously when there is:

• Significant heart or lung disease
• Kidney disease or other major medical illness
• Poorly controlled diabetes, blood pressure or anaemia
• Frailty, poor balance or limited physical reserve
• High risk of blood loss, transfusion or blood clots
• Limited home support or an unsuitable recovery environment
• One knee that is substantially more symptomatic than the other

Potential advantages of simultaneous surgery

• One anaesthetic and one hospital admission
• One combined period away from work or routine responsibilities
• One rehabilitation programme for both knees
• Both arthritic knees are treated without waiting for a second operation

Important limitations and risks

• A longer and more demanding surgical event
• Greater blood loss and a higher likelihood of transfusion in some studies
• Potentially higher risk of certain medical complications in less suitable patients
• More difficult early mobility because both knees are recovering
• Greater need for coordinated physiotherapy, nursing and family support

The second operation should not be scheduled only by the calendar. The first knee and the patient’s overall recovery should be ready.

1. Confirm that both knees need replacement

Symptoms, examination and standing X-rays should show that both knees are sufficiently affected.

2. Assess medical risk

Blood tests, heart and lung assessment, diabetes control, kidney function, anaemia and other medical issues are reviewed.

3. Evaluate rehabilitation capacity

The team considers muscle strength, mobility, balance, home access, caregiver support and the patient’s ability to participate in rehabilitation.

4. Discuss patient priorities

Work, caregiving responsibilities, travel, recovery support and willingness to undergo one larger recovery or two separate recoveries are discussed.

Is bilateral knee replacement safe?

It can be performed safely in carefully selected patients, but the procedure may carry greater medical and rehabilitation demands than replacing one knee. Individual risk assessment is essential.

Is it better to replace both knees together or separately?

There is no universal answer. Simultaneous surgery may suit a medically fit patient with severe arthritis in both knees, while staged surgery may be safer or easier for another patient.

Can robotic assistance be used for both knees?

Robotic assistance may be used in selected bilateral knee replacement procedures depending on the system, surgical plan and surgeon’s assessment. The technology assists the surgeon; it does not determine whether both knees should be replaced together.

Will I be able to walk after both knees are replaced?

Walking generally begins with supervision and an appropriate walking aid according to the treating team’s protocol. The exact timing and level of assistance vary between patients.

How is the timing of staged surgery decided?

The second operation is planned after reviewing healing, mobility, strength, blood tests, medical recovery and the condition of the other knee.