Total Knee Replacement
Total knee replacement is a surgical procedure in which the damaged or worn out surfaces of the knee joint are removed and replaced with an artificial implant. The knee is made up of the femur (thighbone), tibia (shinbone) and patella (kneecap). The two menisci, the soft cartilage between the femur and tibia, serve as a cushion and help absorb shock during motion. Arthritis (inflammation of the joints), injury or other diseases of the joint can damage this protective layer, causing extreme pain and difficulty in performing daily activities.
Knee implants are artificial devices that form the essential parts of the knee during knee replacement surgery. The knee implants vary by size, shape, and material. Implants are made of biocompatible materials that are accepted by the body without producing any rejection response. Implants can be made of metal alloys, ceramic or plastic, and can be joined to the bone. The metals used include stainless steel, titanium, and cobalt chrome; whereas, the plastic used is polyethylene.
Components of a Knee Implant
The components of a knee implant replicate the natural shape and structure of the knee joint. The components used may depend on the size of your body and vary from patient to patient. There are 3 components in a knee implant:
- The femoral component is generally made of metal and curves around the thighbone. It has a channel that allows the kneecap to move up and down as the knee is in motion.
- The tibial component is usually a flat metal platform with a plastic (polyethylene) cushion. The metal portion has a stem that goes into the tibia for stability. The plastic portion, also known as a spacer, acts as a cushion between the femoral and tibial metallic components.
- The patellar component is a dome-shaped device made of polyethylene that replicates the patella.
Knee Implants for Women
Knee replacement surgery may be associated with pain and limited motion if an implant does not suit your particular anatomy. Implants specific to women’s knee are provided by some companies like Zimmer and Biomet.
The unique features of knee implants that are specifically designed for women include:
- It has a thin profile that reduces bulkiness and increases the range of motion.
- It fits the narrow shape of the female knee and prevents overhanging that can cause damage to ligaments and tendons.
- The angle between the hip and knee that allows movement of the kneecap over the thigh bone is different in women. Women-specific implants meet this requirement.
There is no clinical evidence whether gender-specific implants are better than the standard ones, but they are found to be useful in women. Discuss your options with your surgeon to choose the best implant that is suitable for you.