Bilateral Knee Replacement (Simultaneous)

A total knee replacement is a surgical procedure to replace the ends of the bones forming the knee joint with prosthetic parts. One of the most commonly performed surgeries by orthopedic surgeons, the surgery has evolved over the past decades. With improvements in techniques, implants, and instruments, patients are able to get back to their routines sooner. 

Osteoarthritis is the most common cause of knee pain requiring joint replacement surgery. The arthritis is usually initially managed with conservative treatments before going for joint replacement. Conservative management includes physical therapy, nonsteroidal anti-inflammatory drugs, cortisone injections, and viscosupplementation. 

Total knee replacement of both knees.

Total knee replacement of both knees.

Often both the knees may be involved in which conservative management has failed. These patients may require bilateral knee replacement i.e replacement of both the knees. 

The surgery may be performed in a single operation known as simultaneous bilateral knee replacement. Bilateral knee replacement may also be performed in a staged manner, usually, the second knee is replaced after an interval of 3 months or more.

The decision regarding staged or simultaneous surgery depends on a number of patient factors. If there are no limitations for simultaneous surgery, the pros and cons of the simultaneous procedure are discussed with the patient.

Ideally, a patient scheduled for simultaneous bilateral knee replacement is often younger in age, nonobese, and free from cardiopulmonary comorbidities. Any chronic heart, lung, or kidney disease may increase the risks of surgery for both the knee together.

Cruciate retaining polyethylene bearing

Cruciate retaining polyethylene bearing

Cruciate retaining femoral component

Cruciate retaining femoral component


The above images show cruciate retaining polyethylene insert and femoral component. The cruciate retaining design is ideal for patients with non inflammatory knee disease and a healthy posterior cruciate ligament. The  cruciate  retaining design involves less cutting of the bone but the exposure during surgery is less as compared to the posterior stabilized design.

The patients undergoing simultaneous bilateral knee replacement often require less time off work. Although the patients may spend 1-2 days more in the hospital after the procedure they are able to save time required for the second surgery.

The patients are also able to get relief from pain and stiffness in both the knees. In a staged surgery, the patients tend to keep the operated knee in a similar position as the non operated knee. This may lead to reduced movements in the operated knee in case of a deformity in the unoperated knee.

The patients go through rehabilitation together for both the knees which leads to an earlier return to function without having to wait for a second surgery. The bilateral knee replacement is also more cost-effective than a staged procedure.

The simultaneous bilateral knee replacement usually has a higher risk of complications than a staged surgery. The surgery as well as the anesthesia time is prolonged in the case of simultaneous operation. The prolonged surgery may lead to increased blood loss, which may require a blood transfusion.

The risks of forming blood clots, infections, and cardiopulmonary complications are also significantly higher in the case of simultaneous bilateral knee replacement. The patients usually go to inpatient rehabilitation centers after the hospital stay. Although there is greater patient care at inpatient rehabilitation centers, often they are associated with increased infection risks.

With advances in total knee replacement, unless contraindicated a greater number of patients are undergoing simultaneous bilateral knee replacement surgery. If you are a candidate for bilateral knee replacement, discuss the pros and cons of a simultaneous procedure with your surgeon.

Read more about Knee Total Replacement here.

My name is Dr. Suhirad Khokhar, and am an orthopaedic surgeon. I completed my MBBS (Bachelor of Medicine & Bachelor of Surgery) at Govt. Medical College, Patiala, India.

I specialize in musculoskeletal disorders and their management, and have personally approved of and written this content.

My profile page has all of my educational information, work experience, and all the pages on this site that I've contributed to.