Bilateral Knee Replacement (Simultaneous)

Severe arthritis in both knees can make everyday activities such as walking, climbing stairs, and standing difficult and painful. When conservative treatments no longer provide relief, simultaneous bilateral knee replacement may be an option. This procedure replaces both damaged knee joints during a single operation, allowing patients to address both knees at the same time.

At Complete Orthopedics, our experienced joint replacement surgeons use advanced techniques to reduce pain, restore mobility, and improve quality of life.

This page explains who may benefit from simultaneous bilateral knee replacement, how the procedure is performed, and what to expect before, during, and throughout the recovery process.

How Common It Is and Who Gets It

Many adults have arthritis in both knees. Some eventually need knee replacement in both joints. A smaller number of these patients are candidates for simultaneous bilateral knee replacement. This option is most often recommended for younger, nonobese patients who do not have major heart, lung, or kidney conditions.

Why It Happens

Osteoarthritis is the main cause of knee pain requiring knee replacement. With arthritis, the smooth cartilage wears away, causing bone-on-bone contact, swelling, and stiffness. When both knees are affected and conservative care fails, replacing both knees may be discussed.

How the Body Part Normally Works

The knee joint includes the thigh bone, shin bone, and kneecap. Cartilage helps these bones glide smoothly. Ligaments provide stability, and muscles support movement. When cartilage wears down in both knees, pain and deformity make everyday activities hard.

What You Might Feel

People needing bilateral knee replacement often have pain, stiffness, swelling, trouble walking, and reduced motion in both knees. They may struggle with standing, climbing stairs, or daily tasks. Pain may be worse with activity and better with rest.

How Doctors Find the Problem

Diagnosis includes an exam, X-rays, and sometimes magnetic resonance imaging. These studies show the amount of cartilage loss and help identify whether both knees have severe arthritis. Doctors also review medical history to ensure the patient is safe for simultaneous surgery.

Total knee replacement of both knees.

Classification

Patients may fall into two groups:
• Those able to undergo simultaneous bilateral knee replacement.
• Those who require staged surgery, with each knee replaced at different times.

The decision depends on health status, age, body weight, and risks related to anesthesia.

Other Problems That Can Feel Similar

Knee pain may also be caused by ligament injuries, meniscus tears, tendon irritation, bursitis, or referred pain from the hip or spine. These issues must be ruled out before choosing knee replacement.

Treatment Options

Non-Surgical Care
Before surgery, patients may try physical therapy, anti-inflammatory medicines, cortisone injections, and viscosupplementation. These options may help temporarily but do not stop arthritis from worsening.

Surgical Care
Simultaneous bilateral knee replacement replaces both knee joints during one surgery. Staged surgery replaces one knee first and the other knee months later. The implants may include cruciate retaining designs, which preserve the posterior cruciate ligament and require less bone cutting. The decision between simultaneous and staged surgery is made after reviewing risks, benefits, and patient preferences.

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.

Expert Opinions

Orthopedic surgeons emphasize the importance of individualized patient care plans. According to experts, the decision between SBTKR and StBTKR should be made collaboratively by the patient and their healthcare team, considering all medical, physical, and lifestyle factors.

Patient Experiences

Patients who have undergone SBTKR often report intense initial recovery periods but appreciate the simultaneous improvement in both knees once they recover. In contrast, patients opting for SBTKR may experience a less demanding initial recovery but must prepare for a second recovery period when the other knee is replaced.

Recovery and What to Expect After Treatment

Recovery may be more intense after simultaneous surgery because both knees heal at the same time. Patients may spend slightly longer in the hospital and often go to an inpatient rehabilitation center afterward. Therapy begins immediately and continues for months. In staged surgery, recovery happens twice but is easier each time because only one knee heals at once.

Possible Risks or Side Effects

Simultaneous bilateral knee replacement has higher risks than replacing one knee at a time. Risks include increased blood loss, need for transfusion, blood clots, infections, and cardiopulmonary issues. Longer anesthesia time also increases risk. Inpatient rehabilitation may raise the chance of infection.

Long-Term Outlook

Long-term outcomes for simultaneous and staged replacements are similar. Patients often experience better mobility, less stiffness, and improved quality of life. Many appreciate having both knees recover together, which can shorten overall recovery time.

Cost Information

This procedure using the CPT code 27447 (performed twice) is covered by Medicare and most major insurance carriers (Aetna, Anthem BCBS, Cigna, Empire BCBS, UnitedHealthcare), as well as most workers’ compensation and no-fault insurance plans. Your out-of-pocket cost depends on your specific plan, deductible, and the medical necessity criteria that apply to your case.

Call our billing team at Complete Orthopedics at (631) 981-2663 before scheduling to verify your coverage and discuss expected out-of-pocket costs. For the full list of carriers we accept and patient billing protections, see our Insurance Information page.

Summary and Takeaway

Simultaneous bilateral knee replacement treats severe arthritis in both knees during a single operation. It can shorten total recovery time and reduce the need for two separate hospital stays. However, it carries higher short-term risks and is offered only to healthy, well-prepared patients. Staged surgery remains a safer choice for many people. The decision should be based on a full evaluation and discussion with the surgeon.