🦴 Quick Facts from Prof. Dr. Göçer
- Bilateral knee replacement is performed when osteoarthritis affects both knees.
- There are two methods: simultaneous (both knees in a single surgery) and staged (knees at separate times).
- The simultaneous method offers a single anesthesia and a single recovery period; the staged method, however, may reduce risks in some patients.
- The AAOS recommends the simultaneous approach for healthier, lower-risk patients.
Knee osteoarthritis is a progressive condition that often affects both knees simultaneously. Bilateral knee replacement involves replacing both knee joints with prostheses in patients whose knee joints are severely worn. This procedure can be performed on both knees in a single surgery (simultaneous) or at separate times (staged).
What Is a Bilateral Knee Replacement?
A bilateral knee replacement is a joint replacement procedure performed in patients with advanced osteoarthritis in both knees. Since knee osteoarthritis is generally a degenerative and bilateral condition, in many patients both knees become affected to a similar degree over time. In such cases, treating just one knee may not be sufficient.
The basic principle of the procedure is the same as that of a unilateral replacement: the damaged joint surfaces in each knee are removed and replaced with artificial components. The difference lies in the fact that this procedure is performed on both knees simultaneously and in how the timing of the procedures is planned.
The Difference Between Simultaneous and Staged Approaches
Bilateral knee replacement can be performed using two different approaches. Which one is appropriate is determined based on the patient’s overall health. The table below compares the general characteristics of the two methods.
| Characteristic | Simultaneous | Staged |
|---|---|---|
| Timing | Both knees in a single surgery | Knees in separate sessions |
| Anesthesia | Single anesthesia | Two separate anesthesias |
| Recovery period | Single, combined recovery period | Two separate recovery periods |
| Overall burden | Greater stress on the body | Less burden each time |
| Suitability | Healthier, low-risk patients | May be safer for patients with comorbidities |
The main advantage of the simultaneous approach is a single surgery and a single recovery period, which can reduce overall cost and duration. However, operating on both knees at the same time places a greater burden on the body. With the staged approach, since each surgery is planned separately, risks can be managed more easily, particularly in patients with heart or lung disease.
Who Is a Candidate for Bilateral Knee Replacement?
Bilateral knee replacement is considered for patients with advanced osteoarthritis in both knees who have not benefited from non-surgical treatments. The choice of method depends on the patient’s overall condition:
- Advanced osteoarthritis in both knees: Both knees are significantly worn and painful.
- Insufficiency of non-surgical treatments: Symptoms that persist despite physical therapy, medication, and injections.
- General health status: The patient’s overall health must be suitable for the procedure.
- Significant decline in quality of life: Pain in both knees significantly limits daily life.
According to Prof. Dr. Hasan Göçer, the decision on whether to choose a simultaneous or staged approach should be made after carefully evaluating the patient’s cardiopulmonary status and overall health; the primary goal is to maintain the patient’s safety at the highest level while treating both knees.
Clinical Assessment by Prof. Dr. Hasan Göçer
“In my clinical practice, I emphasize that the most critical decision in bilateral knee replacement is whether to perform the procedures ‘simultaneously or separately.’ While the simultaneous approach offers a single recovery period for young patients in good general health, the staged approach may be safer for patients with comorbidities.”
Prof. Dr. Hasan Göçer — Orthopedic and Traumatology Specialist
The practical importance of this approach stems from the fact that the decision is personalized rather than standardized. International guidelines also recommend the simultaneous approach for healthier, lower-risk patients. In the long term, however, both methods are reported to yield similar results in terms of pain relief and function.
How Is Bilateral Knee Replacement Surgery Performed?
Bilateral knee replacement surgery is planned according to the chosen method. In the simultaneous approach, both knees are operated on in a single session, while in the staged approach, they are operated on in separate sessions. The procedure performed on each knee follows the same steps as a unilateral total knee replacement.
- Anesthesia: The appropriate anesthesia method is administered to the patient.
- Access: The joint is accessed through an incision in the front of the knee.
- Removal of Damaged Surfaces: Worn cartilage and bone surfaces are debrided.
- Prosthesis Placement: The appropriate components are implanted; in the simultaneous approach, the procedure proceeds to the second knee.
- Closure: The incision(s) are closed while checking for stability.
Since both knees are treated simultaneously in a bilateral procedure, the surgery takes longer and places a greater burden on the body. For this reason, a preoperative general health assessment is of great importance.
Bilateral Knee Replacement Recovery Process
The recovery process for bilateral knee replacement can be more intensive than that of a unilateral procedure, especially with the simultaneous approach, because both knees heal at the same time. In the early stages, a physical therapy program that exercises both knees is implemented.
- Early phase (first few days): Standing up and walking with assistance begin under the supervision of a physical therapist.
- First weeks: Range-of-motion and strength exercises are performed for both knees.
- First months: A gradual return to daily activities is facilitated.
- Later stage: The patient enters a phase where pain in both knees decreases and movement becomes easier.
Regaining independence in the first weeks following simultaneous surgery may take slightly longer than with unilateral surgery; however, patients generally make up for this difference in the following weeks. Regular participation in physical therapy is the most critical factor in the process.
From Surgery to Recovery: How Does the Process Progress?
| Stage | Time | What Happens? |
|---|---|---|
| Evaluation | Pre-surgery | Both knees and overall health are assessed; the method (simultaneous/staged) is selected |
| Surgery | Surgery day(s) | The prosthesis is implanted in one or two sessions, depending on the selected method |
| Early Recovery | First Few Days | Standing and walking begin with physical therapy |
| Physical Therapy | Weeks–months | Range of motion and strength are gradually increased for both knees |
| Follow-up | Long-term | The condition of the prostheses is monitored through regular checkups |
Evaluation and Surgery: The condition of both knees and the patient’s overall health are evaluated; the appropriate method is selected, and the prosthesis is implanted.
Recovery and Physical Therapy: Walking begins in the early stages; range of motion and strength are gradually regained in both knees.
Follow-up: The condition of the prostheses is monitored through regular follow-up visits over the long term.
Frequently Asked Questions
Can both knees be operated on at the same time?
Yes; both knees can be replaced in a single surgery (simultaneous approach). This involves a single anesthesia and a single recovery period. However, since it places a greater strain on the body, it is preferred for patients with good overall health and low risk. The decision is made on a case-by-case basis.
Is it better to have bilateral knee replacements or to have them done one at a time?
The long-term outcomes of both approaches are similar; the main difference lies in the balance between safety and convenience. While the simultaneous approach offers a single recovery period, the staged approach may be safer for patients with comorbidities. The most appropriate option is determined based on the patient’s overall health.
How long does recovery from a bilateral knee replacement take?
Recovery in the first few weeks after simultaneous surgery may be slightly more intense because both knees are healing at the same time. However, patients generally catch up in the following weeks. The process varies depending on the patient’s overall condition and adherence to physical therapy.
Is bilateral knee replacement risky?
In low-risk patients, the overall complication rates for simultaneous and staged approaches are similar. However, in patients with heart or lung disease, operating on both knees at the same time may increase certain risks. Therefore, a preoperative general health assessment is important.
Conclusion
Bilateral knee replacement is performed to relieve pain and restore mobility in patients with advanced osteoarthritis in both knees. While the simultaneous approach offers a single surgery and a single recovery period, the staged approach may be safer for some patients. Since long-term outcomes are similar, the choice depends largely on the patient’s overall health status and safety assessment.
You can begin the consultation process to evaluate your specific situation regarding bilateral knee replacement. Prof. Dr. Hasan Göçer evaluates each patient’s clinical case individually to determine the most appropriate treatment options.
References
- NCBI/PMC, “Comparison of simultaneous bilateral versus unilateral total knee replacement,” 2020 — https://pmc.ncbi.nlm.nih.gov/articles/PMC7161292/
- NCBI/PMC, “The Ideal Timing of Bilateral Total Knee Arthroplasty: Simultaneous Versus Staged”, 2024 — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10989730/
- NCBI/PMC, “Simultaneous bilateral TKA lowers reoperation and cost … meta-analysis,” 2025 — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12548196/
