Healthy Lifestyle Radio Storytime

What is a knee replacement?

A prosthesis is a device that is implanted to perform a particular function that the body has lost or done very defective.

The knee joint is a triple lace bones: the two bumps at the lower end of the femur, called condyles, engage with respective concave surfaces of the tibia, called tibial plateau. Moreover, the patella engages with both femoral condyles.

We therefore have the tibiofemoral joint, medial compartment divided (on the inside of the knee) and lateral compartment (on the outside of the knee) and patellofemoral compartment or joint.

The knee prosthesis replacing one, two or three compartments.

What materials does it compose of?

Used metal alloys and polyethylene. At present, only these materials the most suitable strength, durability and performance to the efforts suffer once implanted in the human body.
What parts make it up?

The femoral component

It is a metal cap similar to the condyles, which is anchored to the bone with a porous surface or using a special cement polymethylmethacrylate.

The tibial component

It is made of polyethylene, in the junction to the bone may have a metal reinforcement. May or may not cemented, as designed.

The patellar component

It is usually a piece of polyethylene cemented. Some surgeons use a variant with metal bracket that is anchored directly to bone without cement.

The design of the components varies depending on the ligaments that can be kept: a more ligaments preserved is said to be less constrained. Ligaments are the collateral and the Crusaders.

Replacement prostheses or rescue are used when the first prosthesis and the bone has worn loose. They tend to have more pieces to fit the areas of bone loss. The problem is that the greater the number of pieces more friction between them and more waste or chips fall off, injuring more bone.

credit to: Dr. Alain Vannineuse, Dr. Roberto Palacio González