I’ve been meeting way too many people who are getting either knee replacements or have just recently had a knee replacement. I started to think about it. What exactly happens during the knee replacement surgery? Do surgeons actually saw off your knee and replace it with an artificial limb? So, I went to the expert, Dr. Sabrina Strickland of Hospital for Special Surgery. I’ve been her patient for years now and have referred dozens of patients her way because she is top-notch in her field.
If you have knee pain, you know that living with chronic knee pain is debilitating. It can stop you from enjoying simple activities like walking, climbing stairs, or even getting a good night’s sleep. When non-surgical treatments no longer provide relief, knee replacement surgery can be a life-changing option. This procedure helps restore function and significantly reduce pain, allowing you to get back to the life you love.
What is a Knee Replacement?
A knee replacement, or knee arthroplasty, is a surgical procedure designed to resurface a knee damaged by arthritis or injury.
“The main goal is to relieve pain and correct or partially correct leg deformity. During the surgery, we remove damaged bone and cartilage from your thighbone, shinbone, and often kneecap and replace them with an artificial surface, also called a prosthesis,” said Dr. Strickland.
This artificial joint is designed to mimic the natural movement of your knee. Think of it as giving your knee a new surface. This new surface allows the joint to move smoothly, without the pain caused by worn-out cartilage.
Who Needs a Knee Replacement?
The most common reason for knee replacement surgery is severe pain from osteoarthritis. This condition wears down the protective cartilage that cushions and protects the ends of your bones. Without this cushion, bones rub against each other, causing pain, stiffness, and swelling.
Other conditions that may lead to knee replacement include:
- Rheumatoid or inflammatory arthritis: An autoimmune disease where the body’s immune system attacks the joint lining.
- Post-traumatic arthritis: Arthritis that develops after a serious knee injury, like a fracture or ligament tear.
- Knee deformity: Issues like being bow-legged or knock-kneed that cause uneven wear on the joint.
“Surgery is recommended only after other treatments have failed. These may include physical therapy, anti-inflammatory medications, steroid injections, platelet-rich plasma injections, and weight loss. If you still experience severe pain that limits your daily activities, disrupts your sleep, and reduces your quality of life, you might be a candidate for knee replacement,” said Dr. Strickland.
Types of Knee Replacement Surgery
Not all knee replacements are the same. Your surgeon will recommend a specific type of surgery based on the extent of the damage to your knee.
Total Knee Replacement (TKR)
This is the most common type of knee replacement. In a total knee replacement, the surgeon resurfaces two to three compartments of the knee joint: the end of the thighbone (femur), the top of the shinbone (tibia), and often the back of the kneecap (patella). This procedure is ideal when arthritis has caused widespread damage throughout the entire knee.
Partial Knee Replacement (PKR)
A partial knee replacement, or unicompartmental knee arthroplasty, is an option when damage is confined to a single compartment of the knee. Your knee has three main compartments: the medial (inner), lateral (outer), and patellofemoral (front, between the kneecap and thighbone).
If only one of these is damaged, a surgeon can replace just that section. This procedure is less invasive, involves a smaller incision, and often leads to a quicker recovery compared to a total knee replacement.
Revision Knee Replacement
A revision surgery is performed to replace a failed or worn-out knee implant. Artificial joints don’t last forever. They can become loose, worn, or infected. A revision procedure is typically more complex than the original surgery because the surgeon must remove the old implant before fitting a new one.
What Are the Prosthetics Made Of?
The artificial joints used in knee replacements are marvels of modern engineering. They are made from durable, body-safe materials designed to withstand years of movement. Dr. Strickland told me there are four different types, including:
- Femoral Component: The part that fits onto the end of your thighbone is usually made of a strong, polished metal alloy, like cobalt-chromium.
- Tibial Component: The piece that covers the top of your shinbone is a flat metal platform, often made of titanium or cobalt-chromium.
- Plastic Spacer: A medical-grade polyethylene spacer sits between the two metal components. This spacer acts as the new cartilage, providing a smooth surface for the joint to glide on.
- Patellar Component: In some cases, the back of the kneecap is also resurfaced with a dome-shaped plastic piece.
These components are secured to your bone using either bone cement or a “press-fit” method, where the implant has a porous surface that allows your natural bone to grow into it over time.
The Knee Replacement Procedure: A General Overview
While specifics can vary, the general surgical process follows a clear path. The surgery usually takes one to two hours to complete.
“Knee replacement surgery is a transformative procedure for patients suffering from chronic pain and limited mobility. While the process involves removing damaged bone and cartilage with precision tools, including surgical saws, the goal is to restore function and improve quality of life. Recovery times can vary, but with dedication to physical therapy, many patients see remarkable improvements within weeks,” says Dr. Sabrina Strickland.
- Anesthesia: You will be given either general anesthesia (where you are asleep) or regional anesthesia (like a spinal or epidural block), which numbs you from the waist down.
- Incision: The surgeon makes an incision over the front of your knee to access the joint.
- Removing Damaged Bone and Cartilage: Using precise surgical tools, including special saws, the surgeon cuts away the damaged cartilage and bone from the femur (thighbone) and tibia (shinbone). This process involves removing the worn surfaces of the knee so that the artificial implant can fit securely and work properly. In a total knee replacement, this step involves resurfacing the entire joint, while in a partial knee replacement, only the damaged section is sawed off and replaced, leaving the healthy parts of your knee intact.
- Positioning the Implants: The metal components are attached to the prepared bone surfaces.
- Inserting the Spacer: The plastic spacer is placed between the metal parts to create a smooth gliding surface.
- Resurfacing the Kneecap: If needed, the underside of the kneecap is prepared, and a plastic button is placed.
- Closing the Incision: The surgeon assesses the knee’s motion and stability before closing the incision with absorbable sutures, regular sutures, or staples.
Recovery Time
Recovery from knee replacement surgery usually takes several months, especially for a total knee replacement. Many patients go home the same day, while others spend a night in the hospital before beginning physical therapy to regain strength and mobility. It can take anywhere from three months to a year to fully recover, depending on your health, age, and dedication to rehabilitation.
Some patients recover more quickly, especially after a partial knee replacement, which can lead to a shorter, less intensive recovery period than with a full replacement. However, every patient is different, so your recovery timeline may vary.
Benefits and Risks of Surgery
Making the decision to have surgery requires weighing the potential benefits against the risks.
Benefits
The primary benefit of knee replacement surgery is significant pain relief. For most people, this means a return to activities they once enjoyed. Other benefits include improved mobility, better leg alignment, and an overall enhanced quality of life. Many patients can walk, swim, garden, and play golf again without the burden of constant pain.
Potential Risks
Knee replacement is a safe and common procedure, but, like any major surgery, it carries risks. These can include:
- Infection: Both at the incision site and deep within the new joint.
- Blood clots: Clots can form in the leg veins and may travel to the lungs.
- Implant problems: The prosthesis can loosen or wear out over time.
- Nerve or blood vessel damage: Rare but can occur during surgery.
- Stiffness: Some patients may develop scar tissue that limits the knee’s range of motion.
Your surgical team will take many precautions to minimize these risks, such as administering antibiotics and blood thinners.
The Road to Recovery
Your recovery journey begins as soon as you wake up from surgery. Physical therapy is a critical part of this process. A therapist will help you start walking and performing exercises, often on the same day as your surgery. Modalities such as portable ice machines, stretching straps, and compression sleeves can help with post-operative pain and swelling.
The goal of therapy is to strengthen your new knee and restore its range of motion. You will be given a specific exercise plan to follow both in the hospital and at home. It’s important to stick to this plan to achieve the best possible outcome. Full recovery can take several months, but you’ll notice steady improvement week by week. With dedication, you can regain your mobility and leave chronic knee pain behind.
Knee replacement surgery is a proven solution for individuals suffering from severe knee pain that no longer responds to conservative treatments. By replacing a damaged joint with a new, artificial one, this procedure can restore function and dramatically improve your quality of life. If you think you might be a candidate, talk to an orthopedic surgeon like Dr. Sabrina Strickland at the Hospital for Special Surgery in Manhattan to explore your options and decide if this is the right step for you.
