What is a knee replacement?

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What is a knee replacement?

What is the Knee Joint

The knee is a hinge joint that connects the thigh bone (femur) to the shin bone (tibia). It is located in the middle of the leg and is responsible for supporting the body's weight, as well as facilitating movement, such as walking, running, jumping and squatting.

Structure of the Knee Joint

The knee joint is made up of four main parts: the femur, the tibia, the patella (kneecap) and the meniscus. The femur has two rounded ends, which fit into two concave depressions on the top of the tibia. The patella sits in front of the knee joint and slides along a groove in the femur as the leg bends and straightens. The meniscus is a C-shaped piece of cartilage that sits between the femur and the tibia, which helps absorb shock and distributes the load evenly across the joint.

How the Knee Joint Works

The knee joint is surrounded by ligaments and muscles that provide stability and support. The muscles that surround it include the quadriceps, hamstrings, and calf muscles. These work together to provide movement and strength allowing the joint to bend and straighten. When you walk or run, your knee joint acts as a shock absorber that helps distribute your weight evenly across your body.

Common Causes of Knee Pain

Knee pain can be caused by a variety of conditions, including:

Arthritis: Osteoarthritis and rheumatoid arthritis are the two most common types of arthritis that affect the knee joint. These conditions can cause pain, stiffness, and inflammation in the joint. Osteoarthritis is caused by general wear-and-tear that reduces the amount of protective cartilage and can lead to bone rubbing against bone. Rheumatoid arthritis is a condition whereby a person’s immune system begins to attack joint tissue which causes inflammation and can lead to degradation.

Bursitis: Bursitis is a condition that occurs when the small, fluid-filled sacs (bursae) that cushion the knee joint become inflamed, which may cause pain and tenderness.

Ligament Sprains and Tears: The knee joint has four main ligaments: the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL). Sprains and tears in these ligaments can cause pain and instability in the knee.

Meniscal Tears: The meniscus can be torn due to sudden twisting or jerking movements, leading to pain, swelling, and difficulty moving the knee.

Patellar Tendinitis: Tendinitis is a condition that occurs when the tendons that attach muscles to bones become inflamed, which results in pain. In the knee, patellar tendinitis affects the tendon that connects the kneecap to the shin bone.

Knee Replacement Operations

Knee replacement surgery is a surgical procedure that involves removing the damaged part of the knee joint and replacing it with an artificial joint made of metal, ceramic or plastic. Patients can have an adverse reaction to the materials but a simple genetic test designed by ExplantLab can minimise this risk. A replacement is usually recommended for patients who have severe arthritis, damage to the knee joint or who have not been able to find relief from pain with other treatments.

During the procedure, the surgeon will make an incision in the knee and remove the damaged part of the knee joint. The surgeon will then place the artificial joint in its place, and secure it with screws or cement. The surgery usually takes a few hours, and patients typically stay in the hospital for a few days afterwards.

Recovery from knee replacement surgery can take several weeks or months, depending on the patient's overall health and the extent of the surgery. Physical therapy is often recommended to help patients regain strength and mobility in the affected knee.

As with any surgery, there are risks and complications associated with knee replacement surgery. Some of the risks include infection, blood clots, and nerve damage. In some cases, the new knee joint may not function properly or may become loose over time, requiring additional surgery.

In summary, the knee joint is an important part of the human body essential for movement and support. Knee pain can be caused by a variety of conditions, and a replacement operation may be necessary in cases of severe damage or injury. With an artificial knee made of a suitable material, and proper treatment and rehabilitation, patients can often regain mobility and lead a pain-free life.