Arthritis is an inflammation of the joints. The condition can affect one joint or multiple joints, causing pain and stiffness in the affected area. When these symptoms occur in one or both knees, it usually indicates that the cartilage in the joints has worn away. Knee replacement surgery may be done to replace the damaged joints and to relieve symptoms.

During knee replacement surgery, a surgeon replaces the damaged areas of the knee joint with an artificial knee called a prosthesis. A prosthesis is made of metal, plastic, and ceramic. It can help restore nearly all function of the damaged knee and relieve arthritis pain.

A doctor will usually recommend knee replacement surgery if the pain in your knee is interfering with your daily activities and negatively affecting your quality of life. In most cases, this type of surgery is performed in people over age 60, as younger people tend to wear out their artificial knees more quickly.

When severe arthritis affects both knees, a doctor may suggest double knee replacement surgery. However, more risk is involved with this type of surgery, so it’s typically only recommended to those who are:

  • physically fit
  • in overall good health
  • motivated to undergo physical therapy and rehabilitation after surgery to regain their mobility

Double knee replacement surgery may involve one surgery or two surgeries.

When both knees are replaced at the same time, the surgery is known as a simultaneous bilateral knee replacement.

When each knee is replaced at a different time, it’s called a staged bilateral knee replacement.

Either surgery may involve any combination of total knee replacement or partial knee replacement.

With simultaneous bilateral knee replacement, both of your knees will be replaced during the same surgery. The primary advantage of a simultaneous procedure is that there is only one hospital stay and one rehabilitation period to heal both knees.

However, rehabilitation may be slower, as it’s more difficult to use both knees at the same time. In fact, many people who undergo simultaneous bilateral knee surgery need assistance at home as they’re recovering.

Simultaneous bilateral knee replacement also takes longer to perform. This procedure typically takes three to four hours to complete, while staged bilateral knee replacement only takes two hours.

Since simultaneous bilateral knee replacement requires more time and heavier doses of anesthesia, there is an increased risk of complications. The surgery isn’t recommended for those with heart conditions or lung disease. These high-risk groups may experience heart problems or excessive blood loss during and after surgery.

In staged bilateral knee replacement, both knees are replaced in two separate surgeries. These surgeries are done a few months apart. Each surgery lasts about two hours. This staged approach allows one knee to recover before the second knee undergoes surgery.

The main advantage of a staged procedure is the reduced risk of complications. It also requires a shorter hospital stay.

However, since this procedure requires two surgeries, the overall rehabilitation period can be much longer. This may delay your return to some of your daily activities.

The risks associated with both simultaneous and staged bilateral knee replacement surgeries include:

People over age 65 are more likely to experience complications from double knee replacement surgery. Men are also at a greater risk for complications than women.

Immediately after surgery, you’re taken to a recovery room for a few hours before being brought to your hospital room. You’ll remain in the hospital for three to five days after a staged double knee replacement, and up to 10 days after a simultaneous double knee replacement. You’ll be given medications to help ease any pain.

During hospitalization, your doctor will watch for any signs of infection, blood clots, and other possible complications. Your doctor will also show you low-intensity exercises that can improve movement and promote healing in the knees.

You’ll start physical therapy, sometimes within a few hours of surgery, so you can begin transitioning back to normal knee movement.

Most physical therapy programs last between 6 and 12 weeks but may be longer depending on your progress and preexisting physical condition.

Your physical therapy program may include a walking plan and various knee-strengthening exercises to boost mobility. It will also work to restore motion to the knee.

These exercises gradually increase the ability to perform everyday activities, such as walking up and down stairs. A physical therapist will teach you how to do each exercise.

During your rehabilitation period, it’s critical to follow the instructions from your physical therapist and doctor. Adherence will help ensure a complete recovery from your double knee replacement surgery.

Most people recover within 12 months, but your recovery time may differ depending on your age and overall health.

Despite the risks and challenges of undergoing double knee replacement surgery, both simultaneous and staged knee replacements are often successful. If you think you might be a candidate for a double knee replacement procedure, talk to your doctor and discuss your options.