Total Knee Replacement: What to Expect Before, During, and After

Total knee replacement, also known as total knee arthroplasty (TKA), is a common and effective orthopedic surgery designed to alleviate pain and improve the quality of life for individuals suffering from severe knee joint damage, usually due to osteoarthritis. It involves replacing the damaged articular surfaces of the knee joint with smooth metal and plastic components. If you’re considering TKA, understanding the process—from pre-operative preparations to the surgery itself and post-operative recovery—is crucial for setting realistic expectations and ensuring the best possible outcome.

Preparing for Surgery

Medical Evaluation: If you and your orthopedic surgeon decide that total knee replacement is the right option, you’ll need to undergo a comprehensive medical evaluation. This typically includes a physical examination by your primary care doctor to ensure you are healthy enough for surgery and recovery. Patients with chronic conditions like heart or kidney disease may also need to be evaluated by specialists.

Tests: Your surgeon will likely order several tests, including blood and urine samples and an electrocardiogram, to help plan the surgery.

Medications: It’s essential to inform your orthopedic surgeon about all the medications you’re currently taking. They will advise you on which medications to stop and which to continue before the surgery.

Dental Evaluation: A dental evaluation might be necessary to rule out any potential sources of infection that could complicate the knee replacement.

Pre-operative Assessment: You’ll have a pre-operative assessment with a nurse to check your general health and discuss your medications. The nurse will provide instructions on which medications to adjust or stop before the surgery.

Lifestyle Adjustments: In the weeks leading up to surgery, staying as active as possible and strengthening the muscles around your knee can aid in recovery. Your consultant or physiotherapist can recommend specific exercises to improve recovery time. Preparing your home environment for after surgery is also a good idea to ensure you can move around safely and easily.

Anesthesia Considerations: Most knee replacement surgeries are performed under general anesthesia, which requires fasting for about six hours before the procedure. You should not drink anything for two hours before anesthesia, and you may be advised to avoid milk, opting instead for water, black tea, or black coffee. Compression stockings will be needed during and after surgery to prevent blood clots.

During the Surgery

The surgery typically takes one to two hours. The procedure involves several key steps:

1. Anesthesia: You’ll receive either general anesthesia (where you are fully unconscious) or spinal or epidural anesthesia (where you are awake but unable to feel anything below the waist). A nerve block around the knee may also be administered to numb it.
2. Incision: The surgeon will make an incision in the front of your knee to access the patella (kneecap). Traditional knee replacement incisions are typically 8 to 10 inches long, while minimally invasive surgery involves incisions of about 4 to 6 inches.
3. Patella Rotation: The patella is then rotated outside the knee area to provide the surgeon with a clear view of the surgical site.
4. Bone Resurfacing:
   • Femur: The surgeon will carefully measure the bones and make precise cuts to remove damaged bone and cartilage from the end of the femur (thighbone). The end of the femur is then cut and resurfaced to fit the femoral component of the artificial knee. The metal femoral component is attached to the end of the femur and sealed with bone cement.
   • Tibia: Next, the surgeon removes damaged bone and cartilage from the top of the tibia (shinbone) and shapes the bone to fit the metal and plastic tibial components. The tibial tray, the bottom portion of the implant, is fitted to the tibia and secured with bone cement. A polyethylene insert is then snapped into place between the tibial tray and the femoral component to provide support and act as a buffer.
   • Patella: The surgeon might flatten the patella and fit it with a plastic component to ensure a proper fit with the rest of the implant. This plastic piece is cemented to the underlying bone.
5. Trial and Adjustments: A dummy joint will be placed so the surgeon can check that the joint works correctly. Adjustments are made and the bones cleaned before the final prosthesis is fitted.
6. Final Steps: The surgeon will bend and flex the knee to ensure the implant is working correctly and that the alignment, sizing, and positioning are suitable. The incision is closed with stitches or staples, bandaged, and you will be prepped for recovery.

After the Surgery

Hospital Stay: The average hospital stay is two to five days, with total knee replacements typically requiring a longer stay than partial knee replacements.

Pain Management: It’s normal to feel discomfort after surgery. Painkillers will be provided to manage pain in the days and weeks following the operation.

Short-Term Side Effects: Immediately after surgery, you may need oxygen or a blood transfusion. The wound may need to be drained, and dressings will be changed regularly. You will likely feel tired. Swelling in the knee, legs, and feet is common; keeping your leg raised and applying ice packs can help.

Rehabilitation:

• Early Mobilization: Your care team will encourage you to move your foot and ankle to improve blood flow, reduce swelling, and prevent blood clots. They will also recommend breathing exercises and gradually increasing your activity level.
• Physiotherapy: Recovery can take several months and requires regular knee replacement exercises and physiotherapy to improve mobility.
• CPM Machine: You may leave the operating room with your leg in a continuous passive motion (CPM) machine, which gently bends and flexes your new knee while you are lying down.

Realistic Expectations: While most people experience a significant reduction in knee pain and improved ability to perform daily activities after TKA, it’s important to have realistic expectations. Total knee arthroplasty will not enable you to do more than you could before developing arthritis. High-impact activities like running and jumping are generally discouraged to avoid excessive wear on the implant. Appropriate activities include walking, swimming, golf, light hiking, biking, and dancing.

Long-Term Care: With proper activity modification, knee replacements can last for many years. Regular follow-up appointments with your surgeon and adherence to the rehabilitation plan are crucial for long-term success.

Conclusion

Total knee replacement can significantly enhance quality of life for those suffering from severe knee pain. By understanding what to expect before, during, and after total knee replacement surgery, you can approach the procedure with confidence and optimize your chances of a successful outcome. Remember to discuss any concerns or questions with your healthcare team to ensure a smooth and well-informed experience.