TOTAL KNEE REPLACEMENT (TKR)

KNEE REPLACEMENT

Knee replacement, or knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability. It is most commonly performed for osteoarthritis, and also for other knee diseases such as rheumatoid arthritis and psoriatic arthritis. In patients with severe deformity from advanced rheumatoid arthritis, trauma, or long-standing osteoarthritis, the surgery may be more complicated and carry higher risk. Osteoporosis does not typically cause knee pain, deformity, or inflammation and is not a reason to perform knee replacement.

Knee replacement surgery can be performed as a partial or a total knee replacement. In general, the surgery consists of replacing the diseased or damaged joint surfaces of the knee with metal and plastic components shaped to allow continued motion of the knee.

DEGENERATED KNEE

Joints are the tissues that connect bones together and allow them to move. Joints are made up of tissue, and these tissues move as a response to muscle movements.

These tissues undergo a lot of stress over the course of your life. While there is a fluid that prevents joints from experiencing too much friction (known as synovial fluid), every time your joints move they receive a small amount of damage.

Generally the joints regenerate as a response to this damage. But over time these joints can degenerate to the point where they are beyond normal repair. This causes the joints to experience inflammation, and this inflammation is known as degenerative knee joint disease.

SYMPTOMS

• Pain with activities
• Limited range of motion
• Stiffness of the joint
• Swelling of the joint
• Tenderness of the knee
• A feeling the knee may “give out”
• Deformity of the joint (knock-knees or bow-legs)

ARTHRITIS OF THE KNEE

Arthritis of the knee is a condition in which there is loss of the articular cartilage of the femur, tibia, or patella. This can be seen on x-ray as a loss of the space between the two ends of bone.

Because of the loss of the gliding surfaces of the bone, people with arthritis may feel as though their knee is stiff and their motion is limited. Sometimes people actually feel a catching or clicking within the knee. Generally, loading the knee joint with activities such as walking long distances, standing for long periods of time, or climbing stairs makes arthritis pain worse. When the arthritis has gotten to be severe, the pain may occur even when sitting or lying down. The pain is usually felt in the inside part of the knee, but also may be felt in the front or back of the knee. As the cartilage is worn away preferentially on one side of the knee joint, people may find their knee will become more knock-kneed or bow-legged.

Arthritis of the knee usually occurs in people as they enter their 60’s-70’s, but this is variable depending upon factors such as weight, activity level, and knee anatomy. Arthritis may be caused by a variety of factors, including simple wear and tear, inflammatory disorders such as lupus or rheumatoid arthritis, infections, and post-traumatic. People who have had prior injury to their knee, damaging the meniscus or cruciate ligament may also develop arthritis. The end result of all these processes is a loss of the cartilage of the knee joint, leading to bone rubbing against bone.

TOTAL KNEE REPLACEMENT (PROCEDURE)

• Knee replacement surgery is most often performed while you are asleep under general anesthesia.
• The anesthesiologist will continuously monitor your heart rate, blood pressure, breathing, and blood oxygen level during the surgery.
• The skin over the surgical site will be cleansed with an antiseptic solution.
• The doctor will make an incision in the knee area.
• The doctor will remove the damaged surfaces of the knee joint and resurface the knee joint with the prosthesis. The knee prosthesis is made up of metal and plastic. The most common type of artificial knee prosthesis is a cemented prosthesis. Uncemented prostheses are not commonly used anymore. A cemented prosthesis attaches to the bone with surgical cement. An uncemented prosthesis attaches to the bone with a porous surface onto which the bone grows to attach to the prosthesis. Sometimes, a combination of the 2 types is used to replace a knee.
• The prosthesis is generally comprised of 3 components: the tibial component (to resurface the top of the tibia, or shin bone); the femoral [thigh bone] component (to resurface the end of the thighbone; and the patellar component (to resurface the bottom of the kneecap that rubs against the thighbone).
• The incision will be closed with stitches or surgical staples.
• A drain may be placed in the incision site to remove fluid.
• A sterile bandage or dressing will be applied.

BENEFITS

• Severe pain that limits your everyday activities including walking, shopping, visiting friends, getting in and out of chair, gardening, etc.
• Pain waking you at night
• Deformity- either bowleg or knock knees
• Stiffness
• Freedom from pain
• Improved mobility
• Improved quality of life because everyday activities and exercise are easier