How Does a Knee Replacement Work?

Understand the Basics of This Surgical Procedure

When your body is in pain, you want to do everything possible to get rid of that pain. So, when you’re battling the effects of arthritis in your knees, it makes sense that you’d investigate every option available – especially because you want to keep active. For many people suffering from this condition, a total knee replacement is a viable course of action, but you should also understand how this surgical procedure works before you agree to it.

Inside the Knee

The knee is the largest joint in your body, and it’s comprised of the following elements:

• Articular Cartilage – surrounds the end of the bones of the knee, including the knee cap, and cushions the joint
• Patella – your knee cap
• Meniscus – sits between the 2 main bones of the knee and acts as a shock absorber along with the articular cartilage
• Anterior Cruciate Ligament – acts like a rubber band to prevent hyperextension of the knee
• Lateral Collateral Ligament – connects your femur to your tibia on the outside of your knee
• Medial Collateral Ligament – connects your femur to your tibia on the inside of your knee

These moving parts are encased in the Synovial Membrane, a thin layer that excretes a lubricating fluid throughout the entire joint so everything moves seamlessly and without any friction.

Reasons for the Surgery

There are three principal reasons most people choose to undergo knee replacement surgery, most of which are related to arthritis:

1. Osteoarthritis – The cartilage in your knee joint slowly deteriorates, causing your bones to rub together directly
2. Rheumatoid Arthritis – Your immune system attacks the cartilage in your knee joints, causing painful swelling that can distend your joints.
3. Injury-Related Arthritis – Any injury to the joint that damages the cartilage could cause arthritis to set in, albeit often slowly, but possible more premature than age-related arthritis.

Any of these diagnoses could be cause for knee replacement, provided you had failed all conservative treatment options. These include medications, physical therapy, steroid injections, Hyaluronic Acid Injections, genicular nerve blocks, and maybe even regenerative procedures such as stem cells, PRP, A2M, and Amniotic Tissue grafts. You should always consult with your primary care physician and a knee specialist before taking any further steps.

During the Surgery

Knee replacement surgery is formally known as “knee arthroplasty,” and it’s comprised of 4 straightforward steps:

1. Clean the bone – The surgeon removes all of the affected cartilage, along with a bit of bone from the femur and tibia.
2. Insert the replacement parts – Typically made of titanium, metal components are added to your body to replace the removed cartilage, specifically the articular cartilage and meniscus areas.
3. Prepare the patella – Depending upon your specific injury, your patella could be cleaned and receive a plastic tab to aid with movement.
4. Add a spacer – This component is placed in between the metal elements, mimicking the role of the Anterior Cruciate Ligament in form and function.

The entire surgery regularly lasts for 2 hours, contingent upon the severity of your actual joints. You will be under general anesthesia the entire time.

After the Surgery

Total knee replacements have come along way. Now, many physicians use a robot-assisted procedure to pre-plan the crucial cuts and angles, ensuring proper fit of the implants. This helps reduce the time the joint is exposed, which reduces the risk of infection and improves patient outcomes.

1. In most cases, the hospital staff will want to begin mobilizing the joint as soon as possible after the surgery. This usually begins the first day.
2. Many patients often begin walking the same day. Motion is critical to a joint and is extremely important to your recovery to ensure maximum range of motion is achieved.
3. You will usually stay in the hospital for several days recovering, as the medical staff looks out for blood clots and helps with pain management and physical therapy.
4. Once you get home, you will have to watch for swelling, fever, and other potential complications from the surgery.
5. You will have to monitor your wound, diet, and activity with care, all while taking special care to follow through on the physical therapy you began in the hospital.

The fact remains – knee replacement surgery is invasive and considered a major surgery, so evaluating the risks vs. benefits should be something you discuss with your surgeon.

Risks of Surgery

A total knee replacement is major surgery, and with any major surgery, there are risks and possible complications.

• Infection is one of the most serious risks that could prevent a proper recovery following joint replacement. If the joint becomes red, swollen, or feels hot after surgery, there could be an infection. If the joint was found to be infected, many times the implant must be removed so the infection can be treated with high-dose antibiotics prior to re-operation to install the implant again. In very severe cases, the joint could have to be fused if multiple infections prevent installing future implants.
• Continued pain is possible after surgery even though the surgery may have gone entirely as planned. There are many facets to a joint replacement that must be done precisely to ensure proper fit of the implant and proper sizing of the implant selected for the joint.
• In rare cases, patients can have a reaction to the type of metallic implant used for the artificial joint.
• Reduced range of motion and restriction of the joint is possible. This usually occurs as a result of not performing your exercises and stretches as prescribed by the Physical Therapist or your surgeon. In some cases, a follow-up procedure can be done to reduce the adhesions from scar tissue development which can improve the motion.
• You could experience complications from general anesthesia.

In many cases, you will have to make adjustments to your home and your routines. This includes changing how and when you exercise – as your knee implant will wear down faster from high-impact activities like running – and installing temporary rails, guards, and other implements that prevent you from falling.

If you have tried everything and your knee is greatly affecting the quality of your life, knee replacement surgery may be the solution to improving the pain you feel from arthritis in your joints. We encourage you to come see us at Arthritis Relief & Vascular Centers to determine if there is something that can be done instead of knee replacement surgery.