WHAT IS A TOTAL KNEE REPLACEMENT?

Many people have heard of or had a friend, family member or acquaintance have a total knee replacement. Just the name itself sounds like a major procedure and a major change in lifestyle. Knowing what the surgery entails and what to expect with physical therapy can answer many questions and relate some of the stress and concern people may have.

The knee joint is formed by the tibia (lower leg bone) and the femur (thighbone). The ends of each bone at the joint are covered with a smooth layer of cartilage. Inside the knee joint are two cartilage pads acting as additional cushion called the menisci. Normal menisci and cartilage allows near frictionless and pain-free movement. When the cartilage is damaged, worn down, or disease by arthritis, the joint becomes stiff, painful, and possible inflamed. If an arthritic joint is damaged to the point of constant pain or limited movement the joint may be removed and replaced with an artificial joint, called a prosthesis (total knee replacement).

WHEN IS A TOTAL KNEE REPLACEMENT NECESSARY?

Prior to having a total knee replacement, conservative measures should be taken to try and relieve the pain and improve function. These measures may include pain free strengthening and range of motion exercises prescribed by a physical therapist, injections to either decrease the inflammation or provide lubrication to the joint, or medications provided by your physician. If these measures do not relieve your symptoms and x-rays reveal extensive damage to the joint, a replacement may be necessary.

You will need to be evaluated by an orthopedic surgeon who would do the surgery if warranted. You do not want to wait too long where the pain is so severe you avoid using the joint and thus weakening the surrounding muscles making it difficult to move.

The goal of a replacement would be to relate the pain in the joint caused by the damaged cartilage and improve function. The damaged ends of the bones and cartilage are replaced with metal and plastic surfaces that are shaped to restore knee movement and function.

WHAT IS THE RECOVERY PROCESS?

In general, your orthopedic surgeon will encourage you to use the new joint immediately after surgery. You will often stand and begin walking with a walker or crutches the day after surgery. Most patients will have some temporary pain in the replaced joint because the surrounding muscles are weak fromactivity and the tissues are healing. This pain usually subsides after a few weeks.

For the next 3-6 weeks, exercise and range of motion are the most important part of the recovery process. You may have physical therapy started at your home and then progress to an outpatient clinic after a couple weeks. Recovery depends a lot on the general physical ability and fitness of the patient prior to surgery as well as their dedication to a home exercise program after the surgery.

Physical therapy should include manual therapy to decrease scar tissue and improve patellar (knee cap) mobility, passive range of motion performed by the therapist, and supervised exercises to begin strengthening the surrounding muscles. The main portion of the recovery process lasts between 8-12 weeks though one may continue to improve their strength and range of motion up to 1 year.

After a total knee replacement high impact activities such as running or jumping are forever off limits. Activities such as swimming, golf, bicycling and walking are encouraged once healthy.

Deciding to have a total knee replacement can be a difficult decision, however knowing what to expect from the surgery and what the recovery process is like, can make your decision easier and less stressful.