The anatomy of the knee joint is divided into three main compartments:
If advanced arthritis is limited to a particular compartment, a partial knee replacement may be a good treatment option. During this procedure, only a portion of the knee joint is resurfaced. Similarly to a total knee replacement, the deteriorated cartilage at the ends of the bones are removed, and replaced with metal components that reconstruct the knee joint surfaces. These metal components are typically cemented into the bone. Only the compartment with advanced arthritis is resurfaced with the metal implants, and the healthy cartilage and bone of the other compartments are preserved.
With this procedure, the damaged bone and cartilage of the knee is removed, and replaced with prosthetic implants. These metal components reconstruct the knee joint surfaces, and are typically cemented into the bone. The cartilage on the back of the patella (kneecap) is also trimmed, and resurfaced with a plastic button. Sometimes, the kneecap is not resurfaced. A dense plastic component is placed in-between the new metal resurfacings, which creates a smooth articulation of the knee joint.