Dr. Biehl has had vast experience in various types of knee replacements and would be happy to discuss what would be best for you.
The knee is the largest joint in the body. It is commonly referred to as a “hinge” joint because it allows the knee to flex (bend) and extend. However, the knee has the additional ability to rotate and translate (glide). The knee joint is formed by the tibia (shin bone), the femur (thigh bone) and the patella (knee cap). Each bone end is covered with a layer of smooth, "articular" cartilage that cushions and protects while allowing near frictionless movement. Cartilage, which contains no nerve endings or blood supply, receives nutrients from the fluid contained within the joint. When a knee joint has a continuous undamaged articular cartilage surface intact, it is usually pain free. As the cartilage surface is damaged or wears out a patient then begins to develop knee pain.
When it seems like you've tried everything and still have severe knee pain, it may be time to consider knee replacement surgery. There are two major different types of knee replacement procedures. Dr. Biehl may recommend to relieve your knee pain with a partial knee replacement, also called uni-compartmental replacement, or total knee replacement. This is based mainly on how much of your knee joint is worn out. Doctor Biehl may be able to determine this through his physical examination of your knee, and typically by getting an X-ray or MRI scan of your knee. Sometimes it requires a knee arthroscopy, to precisely determine how much articular is damaged.
In knee replacement surgery, the ends of the bones that make up the knee are replaced. The new joint works in a similar way that articular cartilage does in a healthy knee. The replacement prevents the bones of the leg from rubbing together at the joint where the articular cartilage was damaged or worn out. This gets rid of the pain. In a uni-compartmental knee replacement only half the knee is replaced. This is done in instances where only one half of the knee joint has become worn out and arthritic. This occurs the minority of the cases. Most knee joints wear out in more than one compartment and require a total knee replacement. Partial knee replacement repairs the side of the knee joint that is damage instead of the entire joint surface as in total knee replacement. Because only one side of the knee is being replaced, a small incision may be used. Because of the small incision, this is sometimes referred to as “minimally invasive” surgery. If two or more compartments of your knee are damaged, Dr. Biehl will probably recommend total knee replacement.
Total knee replacement, or total joint arthroplasty, is the relining of the entire joint (bone end surfaces) with artificial parts called prostheses. There are three components used in the artificial knee. The femoral (thigh) component is made of metal and covers the end of the thigh bone.
The tibial (shin bone) component, made of metal and polyethylene (very tough plastic), covers the top end of the tibia. The metal forms the base of this component, while the polyethylene is attached to the top of the metal to serve as a cushion and smooth gliding surface.
The third component, the patella (kneecap) is usually polyethylene.
The new components are stabilized to your bone ends by using a bone cement or a very tight cementless "press fit".
In some cases, total knee replacement can be done through a smaller incision. This is called minimally invasive total knee replacement. The way a knee replacement will perform depends on your age, weight, activity level and other factors. Only a board certified orthopedic surgeon, like Dr. Biehl, can help you decide whether partial or total knee replacement is right for you.