What is a total knee replacement?

If you're suffering from chronic knee pain that doesn't seem to go away with medication or physical therapy, you may have come across the term “total knee replacement.” But what exactly does it mean? Is it safe? Who needs it, and what can you expect if you undergo the procedure?
This article is a comprehensive and easy-to-understand guide that explains everything you need to know about total knee replacement surgery, from what it is, who needs it, how it’s performed, to what recovery looks like.
What is a Total Knee Replacement?
A total knee replacement, also called knee arthroplasty, is a surgical procedure that replaces a damaged or diseased knee joint with an artificial joint made of metal and plastic. The goal is to relieve pain, improve mobility, and restore function in the knee.
The surgery involves removing the damaged cartilage and bone from the surface of the knee joint and replacing it with prosthetic components that mimic the natural movement of the knee.
Why Do People Need a Total Knee Replacement?
The most common reason for a total knee replacement is osteoarthritis—a condition where the cartilage that cushions the knee joint wears away, leading to pain, stiffness, and reduced mobility. Other conditions that may require knee replacement include:
Rheumatoid arthritis – an autoimmune condition that causes joint inflammation.
Post-traumatic arthritis – occurs after a knee injury or fracture.
Deformities – such as bow-legged or knock-kneed conditions.
Severe knee pain and stiffness – that limits daily activities like walking, climbing stairs, or even getting out of a chair.
Knee replacement is usually recommended when other treatments like medication, injections, physical therapy, or weight loss fail to provide relief.
Types of Knee Replacement
There are different types of knee replacement surgeries based on how much of the joint is replaced:
1. Total Knee Replacement (TKR)
This is the most common type. The surgeon replaces both the inner and outer surfaces of the knee joint, including the femur (thighbone), tibia (shinbone), and the underside of the kneecap.
2. Partial Knee Replacement
Only one part of the knee joint (usually the inner or outer part) is replaced. This is less invasive and may be suitable for people with damage confined to one area of the knee.
3. Kneecap Replacement (Patellofemoral Arthroplasty)
Involves replacing only the kneecap and the groove it sits in. This is used when arthritis affects only the front portion of the knee.
4. Revision Knee Replacement
This is a second surgery to replace or fix a previous knee replacement that has worn out or failed.
How is a Total Knee Replacement Performed?
The surgery typically lasts 1 to 2 hours and is performed under general or spinal anesthesia. Here’s a step-by-step overview of the procedure:
Incision: The surgeon makes an incision over the knee to expose the joint.
Removal of Damaged Tissue: The damaged cartilage and bone are removed from the femur, tibia, and patella.
Implant Placement: The artificial joint components (usually made of metal alloys and medical-grade plastic) are positioned to recreate the knee’s natural movement.
Closure: The surgeon closes the incision and the patient is taken to recovery.
What to Expect After Surgery
Hospital Stay
Most patients stay in the hospital for 2 to 3 days, although some may go home the same day depending on their health and recovery plan.
Pain Management
Pain is managed using medications, ice therapy, and sometimes nerve blocks. Pain usually decreases within a few weeks.
Physical Therapy
Rehabilitation starts within 24 hours of surgery. A physical therapist will guide you through exercises to improve knee strength and flexibility. Full recovery can take 3 to 6 months or longer.
Benefits of Total Knee Replacement
Significant pain relief
Improved mobility and range of motion
Better quality of life
Long-lasting results (implants can last 15–20 years or more)
Risks and Complications
Like any surgery, knee replacement has risks, though serious complications are rare. Some potential risks include:
Blood clots
Infection
Implant loosening or wear
Nerve or blood vessel injury
Stiffness or reduced range of motion
Following your doctor’s advice and attending follow-up appointments can help minimize risks.
Who is a Good Candidate?
You may be a good candidate for total knee replacement if:
You have severe knee pain or stiffness that limits your daily activities.
Conservative treatments have failed.
Knee pain interferes with sleep or rest.
Your knee is deformed or unstable.
You are generally healthy enough to undergo surgery and recovery.
Age is not the only deciding factor. People from their 40s to their 80s have successfully undergone knee replacements.
Tips for a Successful Recovery
Stick to your physical therapy plan.
Keep your surgical wound clean and dry.
Use assistive devices like walkers or canes if recommended.
Follow your medication and pain management plan.
Avoid high-impact activities like running or jumping, especially in the early months.
Eat a healthy diet to aid healing and prevent weight gain.
Alternatives to Total Knee Replacement
Before choosing surgery, doctors often try less invasive options such as:
Physical therapy
Anti-inflammatory medications
Cortisone or hyaluronic acid injections
Weight loss
Braces or orthotic supports
Platelet-rich plasma (PRP) or stem cell therapy (still experimental)
If these options don’t provide relief, a total knee replacement might be the best long-term solution.
Conclusion
A total knee replacement is a life-changing procedure for many people who suffer from chronic knee pain and limited mobility. While it’s a major surgery, the advancements in surgical techniques and prosthetics have made it highly successful and safe.
If you're considering knee replacement, speak to an orthopedic surgeon to evaluate your condition, review your treatment options, and determine the best path for you.
Remember: Early diagnosis, the right guidance, and a positive mindset can lead to a smoother journey toward regaining a pain-free, active lifestyle.