Definition

Total knee replacement surgery is performed by removing the damaged or diseased knee joint and replacing all three knee compartments with an artificial implant.

Alternative Medical Names

• Knee Arthroplasty Surgery
• Knee Joint Replacement

Who is a Candidate?

• A primary care doctor or orthopedic surgeon has recommended a knee replacement.
• Patient has arthritis in all three knee compartments.
• The patient's knee structure is stable and the patient doesn't suffer from severe bone loss around the knee.
• Patient has significant deformity in their knees (bowlegs).
• Patient is age 55 or older.

What is a Total Knee Replacement?

A total knee replacement is a surgical procedure that replaces the damaged or diseased knee with artificial parts. All three compartments of the knee are replaced. The procedure separates the muscles and ligaments around the knee to expose the tissue surrounding the knee joint. The patella (knee cap) is moved out of the way, and the ends of the femur (thigh bone) and tibia (shin bone) are cut to fit the prosthesis.

The two parts of the prosthesis are implanted onto the ends of the thigh bone, shin bone, and the undersurface of the knee cap. The ACL and PCL are removed in this procedure. The procedure is performed by making an incision 8 to 12 inches in length. Before closing the incision, the surgeon bends and rotates the knee, testing and balancing it to ensure that it functions properly. The total knee replacement can last 15 to 20 years.

Since the normal knee kinematics is changed by having a total knee replacement, it may feel different to perform daily activities. The shape and motion of the knee will be different than with the natural knee, so the muscles and ligaments will need to adapt. At first, this may lead to discomfort and fatigue for the patient. The patient's knee may have a clicking sound after the surgery because of the new implant, which is completely normal.

The Allergic Alternative

If a patient is allergic to a type of metal that the implant is made of, then the surgeon will change the type of metal to make it possible for the patient to still have the procedure.

Post Surgery Treatments

• Incision Care - The incision will be covered with a large bandage. A tube may be placed in the incision during surgery to drain extra fluid from the wound. The tubes will be removed by a physician when indicated. The bandage will be changed on the second, third, or fourth day after surgery. The bandage will be changed as needed after that. The incision may be closed by staples or stitches. These will be removed at the direction of the orthopedic surgeon.
• Ice Therapy - The physician may decide the patient will benefit from ice therapy. Ice often helps decrease swelling and discomfort after surgery or exercise. The patient should generally use ice for one hour after exercise and for the first few days after surgery. The physician may instruct the patient to use ice more frequently.
• Continuous Passive Motion - Some physicians use a CPM machine after surgery to help the patient regain the flexion and extension of their knee. The CPM is often started on the first or second day after surgery and used until discharge from the hospital. There are several different CPM machines available. If ordered by a physician, one will be selected and fitted to the patient's leg. Nursing staff will instruct the patient on how to use the machine properly.
  
  It is not usually necessary to use the CPM machine after discharge from the hospital. If it should become necessary, arrangements will be made for a home CPM machine before the patient is discharged. Some surgeons do not use a CPM machine at all. The patient's physician will determine if a CPM machine is appropriate and for how long it should be used.

Discharge Questions

When can the patient shower or take a tub bath?
The patient should continue to take sponge baths until two days after their stitches are out. The patient should not shower or tub bathe until he/she receives permission from their orthopedic surgeon.

How long will the patient need to use walker/crutches?
Approximately three to six weeks, or more in some cases.

How long does the patient wear TED Stockings?
Wear them at least one month, longer if swelling continues after one month. The patient may take them off at night.

When can the patient drive a car?
The patient shouldn't drive a car until he/she sees their physician for their first office visit after the surgery. At that time, the patient should discuss with their physician when would be a good time to start driving again. It will depend upon which knee the patient had repaired and the type of car the patient drives. Do not drive while taking prescription pain medications.

How long are the patient's stitches in?
If the stitches are not removed prior to discharge from the hospital, they will be taken out at the first clinic appointment, approximately one week after discharge. If the staples remain in after discharge, a light gauze dressing may be needed to cover them.

Does the patient need a prosthesis I.D. card for airport metal detectors?
Generally, airport metal detector alarms are set off by artificial knee joints. To be on the safe side, request a letter from the physician stating the situation, but most travelers with artificial knee joints can expect to be "wanded" from head to toe.

Does the patient need to tell their dentist about the knee prosthesis?
Yes. If the patient has any dental work done, including cleaning or minor surgery, he/she should have antibiotics to prevent bacteria spreading from their mouth to their knee.

When may the patient return to work?
It varies, depending on the type of work or volunteer activity. The new knee joint should allow the patient to return to most activities.

Notify a Physician if the Patient has

• Increased pain which is not controlled by pain medications.
• A temperature greater than 101.5º F for longer than six hours.
• Increased swelling, redness or tenderness in the calf.
• Drainage or bleeding from their incision.
• Numbness or tingling in their foot or toes.
• Significant increase in swelling on their operated leg.
  

9/24/2008