Tuesday 3 April 2012

Knee Replacement Surgeries


      The knee is a hinge joint which provides motion at the point where the thigh meets the lower leg.Some or all of the components of the knee joint replaced with a synthetic implant is called knee replacement surgery. The healthy human's knee joint is lined with articular cartilage. Articular has a layer of tissue that provides low-friction and shock-absorbing properties. This protective layer of this cartilage will damage due to Arthritis and injury, causing extreme pain for a patient performing even simple activities. The following are the various types of knee replacement

Total knee replacement

Unicompartmental knee replacement

Viscosupplementation

Autologous chondrocyte implantation



Total Knee Replacement

             
                 A total knee replacement surgery replaces all three compartments of the diseased knee joint. During a total knee replacement, the end of the femur bone is removed and replaced with a metal shell.Typical total knee replacement prosthesis consists of three components: a femoral component, a tibial component, and a replacement for the posterior patellar surface.

The femoral component
                   It is  generally made of non-corrosive metal (most frequently a cobalt-chrome alloy), although some are made of ceramic.
 The tibial component 
                  It is a metal tray topped by a spacer of a special plastic known as ultrahigh molecular weight polyethylene (UHMWPE). UHMWPE exhibits relatively low friction in a metal-plastic joint and resists wear better than many older alternative materials.

 The third component is a replacement for the posterior surface of the patella for articulation with the other components.

Unicompartmental Knee Replacement

                      It involves a procedure similar to that used to implant a total knee replacement. Instead of replacing the entire knee, the uni compartmental prosthesis replaces one condyle, or side, of the knee joint. Because unicompartmental prosthesis replaces one side of the knee, the surgeon does not have to make as large an incision as for a total knee replacement.

Viscosupplementation

                       Viscosupplementation is the injection of a fluid to supplement or replace the natural synovial fluid in the knee joint capsule. In many osteoarthritic knees, the synovial fluid is less viscous and less elastic than that found in healthy knees. The injection affords more lubrication and cushioning for the articular cartilage in arthritic patients. Most viscosupplements contain hyaluronan or hyaluronan derivatives which have viscous and shock-absorbing properties.

Autologous Chondrocyte Implantation

                      Autologous tissue is tissue that has been donated for one's own future procedure. In this case, chondrocyte cells (cells that make cartilage) are harvested from a healthy portion of the knee and are grown in vitro. The cultured cells are then used to repair defects in the articular cartilage of the knee.

Complications

           Some of the risk involved with total knee replacement procedure areas follows.

            Knee dislocation
Infection
Healing period
            Blood clotting
            Stiffening of the knee after the operation
     
                                   
          Knee replacement surgeries can be best done by Dr Santhosh Jacob in Life Med ABC Chennai for more information please visit  www.isomerclinic.com