This is the commonest joint replaced in India. Here the diseased ends of the thigh and leg bones and sometimes the surface of the knee cap are replaced. The components are made of cobalt chrome alloys and poly ethylene. Recently implants made of titanium and oxinium have also been introduced.
When an already replaced joint fails either due to wear and tear after many years, infection, injury or some other problem, the joint needs to be replaced. This is known as revision joint replacement. This is much more difficult and complex compared to a primary joint replacement. These procedures require careful planning and preparation, specialized tools and implants (Prosthesis).These specialized implants are expensive and the procedures are done only by surgeons who have considerable experience in joint replacement surgery.
A knee replacement (also called knee arthroplasty) might be more accurately termed a knee "resurfacing" because only the surface of the bones are replaced.
There are four basic steps to a knee replacement procedure:
Prepare the bone. The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of underlying bone.
Position the metal implants. The removed cartilage and bone is replaced with metal components that recreate the surface of the joint. These metal parts may be cemented or "press-fit" into the bone.
Resurface the patella. The undersurface of the patella (kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending upon the case.
Insert a spacer. A medical-grade plastic spacer is inserted between the metal components to create a smooth gliding surface.
There are several reasons why your doctor may recommend knee replacement surgery. People who benefit from total knee replacement often have:
Severe knee pain or stiffness that limits everyday activities, including walking, climbing stairs, and getting in and out of chairs. It may be hard to walk more than a few blocks without significant pain and it may be necessary to use a cane or walker
Moderate or severe knee pain while resting, either day or night
Chronic knee inflammation and swelling that does not improve with rest or medications
Knee deformity — a bowing in or out of the knee
Failure to substantially improve with other treatments such as anti-inflammatory medications, cortisone injections, lubricating injections, physical therapy, or other surgeries