Understanding a Knee Replacement Surgery
A knee replacement surgery is when a surgeon removes all or part of the joint of the knee and replaces those parts with artificial ones. The surgeon may use the term knee anthroplasty when talking about a knee replacement.
This procedure is done when parts of the knee have been damaged beyond repair such as from an accident or injury, or when a genetic defect or old age has caused irreparable damage to the knee joint. When a patient is in too much pain from a knee injury and physical therapy and other options do not help, a knee replacement may also be their best option. This is considered a major surgery and is not something recommended until all other treatment options have been exhausted.
Understanding the Knee Joint
The knee is made up of several different bones as well as tendons and ligaments, and these work to allow the knee to bend and move and also to connect the upper part of the leg to the lower part of the leg. The thigh bone, called the femur, is connected to the leg bones called the fibula and the tibia via the knee. The patella, which is a triangular bone at the front of the knee, is attached by tendons to the muscles of the thighs. There are two more tendons inside the knee which stretch between the femur and tibia and which keep the tibia from moving out of alignment with the femur. Cartilage covers the bones and this spongy material allows the joints to move freely. Cartilage also absorbs shock from each step and type of impact. There is also a thick layer of tissue called the joint capsule that covers the entire joint.
Diagnosing the Knee Condition
The knee is the largest joint in the human body and also the one most vulnerable to injury as it is not supported by other joints or bones. The pelvis, for example, is supported by the hips bones and leg bones, and the hip bones are supported by the leg bones and pelvis. The knees do not have this additional support and they take on all the shock from walking, running and jumping, and work to support the upper body. Because of this type of support they give, they are prone to injury and just plain “wearing out” after many years. Knee-strengthening exercises can often help, as can building up the muscles of the legs and midsection to better support the knees.
Changes in lifestyle can be in order for those with knee problems, before surgery is recommended. A person that is severely overweight is putting far too much pressure on their knees, especially when they walk up stairs. Because certain sports such as skiing and football put added pressure on the knees, stopping playing may be recommended.
Because of the seriousness of knee replacement surgery, a doctor will want to diagnose knee pain and its cause before recommending this procedure. Osteoarthritis and other degenerative diseases may bring on gradual knee pain over the years, whereas a sudden injury or accident may mean sudden pain. The doctor will need to do a thorough exam with x-rays and other tests to determine the exact cause of knee pain and then to determine the best treatment option.
The structure of the knee is very complex and a partial knee replacement may be a better choice, or physical therapy may help the knee to heal so a patient has less pain and better balance and function. Arthroscopy, which uses a tiny camera to see inside the joint, may be recommended to determine the exact cause of knee pain or the extent of damage due to injury. This may also be done along with a minor surgical procedure that drains fluid from the knee, which may give relief to arthritis sufferers.
Understanding the Surgery
The surgery itself typically takes 2 to 4 hours, and may involve general anesthesia or what is called an epidural, which is a shot that makes the entire lower body numb. An epidural usually results in less blood loss and less risk of bleeding after a surgery. The surgeon will make and incision and then work around the tendons and ligaments of the knee to cut away the damaged cartilage and bone at the end of the tibia and fibula. He or she must also reshape the end of the femur so that an artificial knee or prosthetic can be fitted.
A metal prosthesis is pressed in place and typically a special type of cement is used to keep it adhered. The metal of the prosthesis is coated so that new bone will grow around it. The surgeon will need to check that no tendons or ligaments have been damaged and then the entire area is cleaned with a saline solution and the incision closed.
Recovery may take weeks after surgery and the patient may use a wheelchair for at least the first few days. It’s vital that you discuss concerns about your condition with your doctor and follow his or her recommendations when you have severe or long-term knee pain.