What is Knee Replacement Surgery? Procedure, Types, Recovery, and Risks

Knee replacement surgery is a procedure that resurfaces a knee damaged by arthritis. It involves covering the ends of the bones that form the knee joint, including the kneecap, with metal and plastic implants.

Types of arthritis affecting the knee

• Osteoarthritis, primarily affecting middle-aged and older people, is a degenerative joint disease that may result in the destruction of joint cartilage and nearby bone in the knees.
• Rheumatoid Arthritis – There will be an inflammation of the synovial membrane which will result in an increase in synovial fluid, causing discomfort and stiffness.
• Traumatic Arthritis – Arthritis caused by any kind of injury.

The main target of knee replacement surgery is to restore the parts of the knee that have been damaged due to various types of arthritis and relieve the knee pain that other medical surgeries cannot control.

Knee Anatomy

The knee consists of two long leg bones connected and supported by muscles, ligaments, and tendons. Each of these bones’ ends is covered with a layer of cartilage to protect it from sudden shocks.

The knee consists of two sets of muscles, including the quadriceps muscles, which straighten the legs, and the hamstring muscles, which bend the leg at the knee. Tendons are the stiff connective tissues that connect muscles to bones. Ligaments are the elastic bands of tissues that connect a bone to a bone.

Parts of the Knee

• Tibia – This is the more significant bone of the lower leg, called the shin bone.
• Femur – Known as the upper leg bone or the thigh bone.
• Patella – Also known as the kneecap
• Cartilage – A tissue that covers the surface of a bone at a joint.
• Synovial Membrane – A tissue that lines and seals the joint to form a joint capsule. To lubricate the joints, the synovial membrane secretes synovial fluid.
• Ligament – A strong, flexible connective tissue that encases the joint, providing support and restricting excessive movement.
• Tendon – A tough connective tissue that connects muscles to bones and helps control movement of the joint.
• Meniscus – This is a curved section of the cartilage that acts as a shock absorber.

Reasons to Go Through with the Procedure

The surgery is mainly to relieve the knee from any kind of pain that cannot be controlled with any other kind of treatments. Osteoarthritis is the most common condition that needs to be treated with a knee replacement surgery.

The degradation of cartilage causes osteoarthritis. The damage caused to the bones and cartilages limits the motion and might cause pain. People suffering from severe degenerative joint disease may be unable to perform certain normal activities like bending the knee, climbing up the stairs, since they’re painful.

Additional forms of arthritis, like rheumatoid arthritis or post-traumatic arthritis from a knee injury, can also lead to the breakdown of the knee joint. Furthermore, fractures, torn cartilage, and/or torn ligaments may result in irreparable knee joint injury.

If a few medical treatments don’t seem to be enough, knee replacement surgery is the next best option to be considered. Some of the medical treatments for such degenerative joint disease are:

• Anti-inflammatory medications
• Pain medications
• Limiting painful activities
• Assistive devices for walking
• Physical therapy
• Cortisone injections into the knee joint
• Viscosupplementation injections
• Weight loss

Types of Knee Replacement

Knee replacement surgery is tailored to each individual and is not a universal solution. The type of knee replacement surgery you may need depends on the severity of joint damage, your body structure, lifestyle requirements, and your surgeon’s advice. Understanding these options can help you have more informed conversations with your healthcare provider.

1. Total Knee Replacement (TKR)

This is the most common form of knee replacement surgery. In total knee replacement surgery, the entire joint surface is replaced, including the femur (thigh bone), tibia (shin bone), and sometimes the underside of the patella (kneecap). TKR is typically recommended for individuals with widespread arthritis or joint degeneration affecting multiple areas of the knee. The procedure restores smooth joint movement and helps relieve chronic pain and stiffness.

2. Partial Knee Replacement (PKR)

Partial knee replacement targets only the affected compartment of the knee, preserving the healthy surrounding structures. The knee has three compartments: medial (inner), lateral (outer), and patellofemoral (front of the knee). If damage is isolated to just one area, partial replacement offers a less invasive option with a shorter recovery time. It’s often recommended for younger or more active individuals whose joint damage is limited and localized.

3. Kneecap (Patellofemoral) Replacement

This option targets arthritis that is confined to the area behind the kneecap. The surgeon replaces only the undersurface of the patella and the corresponding groove on the thigh bone. While this is a less extensive surgery, it’s only suitable for a small percentage of patients whose joint deterioration hasn’t spread to other areas of the knee. It may offer faster recovery, but carries a higher risk of future procedures if arthritis progresses.

4. Complex or Revision Knee Replacement

Sometimes, a standard knee replacement may not be sufficient, such as when a previous implant fails or when the joint is severely deformed or weakened by trauma or disease. Complex or revision surgeries often involve custom implants with longer stems, hinges, or stabilizers to restore function and balance. These are more intricate procedures requiring specialized expertise and are usually reserved for patients with advanced or recurring joint issues.

Risks Involved with Knee Replacement Surgery

Like any other medical surgery, the knee replacement surgery can also have its own complications. A few of which may include,

• Bleeding
• Infection
• Blood clots in the legs
• Loosening or wearing out of the prosthesis
• Fracture
• Continued pain or stiffness

The replaced joint might become loose, or get dislodged, and in turn giving way to another replacement surgery in the future. The nerves and the blood vessels may get injured in the area of the surgery resulting in weakness. The joint pain due to this cannot be cured with any surgery.

Preparing for the Procedure

• You will be explained the process of the procedure and made comfortable. You will also be given the chance to ask questions about the procedure and make sure you’re completely fine with the proceedings ahead.
• Your physician will carry out a detailed health evaluation beforehand to confirm you’re fit for the surgery and free from underlying conditions. Several blood tests and diagnostic tests will be administered to you.
• Inform your doctor about any drug, latex, or anesthetic agent allergies you may have.
• Let the doctor know all the medications that you are taking presently before the procedure.
• You should let the doctor know if you are pregnant or suspect that you might be.
• You will be advised by your doctor to fast for 8 hours, preferably at midnight.
• A sedative will be given to you before the procedure.
• You might also be introduced to a physical therapist to consult about rehabilitation prior to the surgery.
• Make sure there is someone at home to take care of the chores for a couple of weeks after you are discharged.

At the Time of the Procedure

Generally, a knee replacement surgery will require you to stay at the hospital. The surgical approach can differ based on your specific medical needs and the techniques preferred by your doctor.

Generally, knee replacement surgery follows this process:

• You’ll be required to change out of your clothes and put on a hospital gown before the procedure begins.
• It is possible that a urinary catheter will be inserted.
• The excess hair around the surgical area will be carefully shaved or trimmed.
• An anesthesiologist will constantly monitor your heart rate, blood pressure, blood oxygen level, and breathing throughout the procedure.
• An antimicrobial solution will be applied to disinfect the area around the surgical site before the procedure begins.
• An incision in the knee area will be made by the surgeon.
• The surgeon will implant artificial metal and plastic components to substitute the damaged parts of the knee joint. Cemented prosthesis is the most common type of prosthesis found.
• With surgical stitches, the incision will be closed after the procedure.
• The fluid from the surgical site will be removed with the help of a drain.
• It will later be covered with a sterile dressing.

Although rare, some patients who undergo total knee replacement may need a follow-up surgery years later. The second surgery may be required due to loosening, fracture, or other issues with the restored joint. Reoperations are often less successful than original surgeries and are fraught with problems. Future replacement technologies and approaches will result in better patient outcomes and fewer problems.

After the Procedure

Following knee replacement surgery, you’ll be taken to a recovery room where your vital signs and pain levels will be closely observed. Depending on your health and how well you’re recovering, you might be discharged the same day or need to remain in the hospital for one to two days.

You’ll begin moving your knee soon after surgery, often with help from a physiotherapist. Pain relief may be provided through injections, tablets, or patient-controlled systems. Some patients may use a CPM (continuous passive motion) machine to aid early mobility.

Once home, it’s important to keep the surgical site clean and dry. You may need to elevate your leg and apply ice to reduce swelling. Pain medications should be taken as advised.

To support your recovery, you might need assistive devices like a walker or cane. Home modifications such as handrails, shower chairs, or raised toilet seats can help prevent falls.

Full recovery can take several months. Follow-up appointments will monitor healing, and a personalized physical therapy plan will guide your rehabilitation.

When to Contact Your Healthcare Provider

Reach out to your surgeon or healthcare provider immediately if you notice any of the following:

• Chest pain or difficulty breathing.
• A fever above 101°F (39°C).
• Bleeding from the surgical site.
• Signs of infection, such as swelling, unusual discharge, redness, warmth, odor, or discoloration around the incision.
• New or increasing pain in your calf, ankle, or foot.
• Intense pain that isn’t relieved by medication.

Conclusion

Knee replacement surgery provides a transformative option for individuals experiencing persistent knee pain and restricted movement caused by arthritis or past injuries. With advances in medical techniques and personalized care plans, many patients experience significant improvements in their quality of life. Gaining insight into the procedure, its advantages, and possible risks can help you make well-informed choices and actively participate in your healing process. Always consult with your healthcare provider to determine the best treatment path for your individual needs.