TOTAL KNEE REPLACEMENT
A total knee replacement, or arthroplasty, is a surgical procedure done when the cartilage covering the surface of the bones in the knee joint, the femur (thigh bone), the tibia (shin bone) and the patella (knee cap) is worn away and the “bone is rubbing against bone.” This abnormal friction causes pain, instability, giving way, swelling, and limited movement. The most common reason for this degenerative process is osteoarthritis. The procedure involves relining of the joint (bone end surfaces) with artificial parts called prostheses.
Surgical procedure
On the day of your procedure, you will be taken to the operating room and given
anesthesia. Once asleep, your knee will be flexed to 90 degrees and a tourniquet will be
applied to the thigh in order to decrease blood flow during surgery. An incision of 8 -
12 inches will be made and the degenerated surfaces of the femur, tibia, and 1/3 of the
back of the patella will be removed. The prostheses will then be attached to the
removed surfaces. If you have good bone quality, a pressfit procedure is performed to
allow bone to grow into the porous prosthesis. However, if you have low bone density,
it may be necessary to use cement as a glue to bond the implants to the surrounding
bone. The prosthesis is designed to act and function like a normal knee joint. Most of
the ligaments and all of the tendons remain intact. A drain will be inserted before the
incision is closed to allow drainage of the wound. Staples are used to close the incision.
On average, the length of the surgery is 2-3 hours.
Pre-operative testing and preparations
You will be advised, if possible, to donate at least 2 units of your own blood
approximately 1 month prior to your surgery date. We will provide you with the
information to schedule this appointment with the American Red Cross. Usually, only
one unit is donated at a time, so it may take you two to three visits to the blood bank to
acquire the necessary amount of blood. In some cases, family members with the same
blood type may donate instead, which is called directed donor blood. If for some
reason you or your family cannot donate blood, screened donor blood from the blood
bank may be used.
Prior to your surgery date, you will be required to undergo routine laboratory tests, EKG and a chest x-ray. If you are over 50 years of age or have any history of cardiac or pulmonary problems, you will also be required to have a clearance by a cardiologist or pulmonologist, respectively. You will also be given information on what medications, both prescription and over the counter, that need to be discontinued preoperatively as many can interfere with wound healing and bleeding time.
What to expect in the hospital post-operatively
You will wake up in the recovery room after the operation is over. During this
time you may be disoriented and tired, which is the normal effects of the anesthesia
wearing off. Once stable, you will be taken to your room where you may be greeted by
friends and family. You will have a catheter placed into your bladder to drain urine.
Your incision will be covered by a sterile dressing and ace bandage which will stay in
place for 2 to 3 days. The drain is removed after 3 days.
It is important to begin moving as soon as possible to prevent blood clots and
speed your recovery. The day after your surgery, you will be visited by a physical
therapist that will assist you. You will have a machine, called a CPM or “continuous
passive motion” which will slowly and progressively bend (flex) and straighten
(extend) your knee. The machine will be used until you reach 90 degrees of flexion.
Getting out of bed is also a very important step in helping your lung function
return to normal. Areas or your lungs collapse during surgery and a couple of days
post-operatively, which is known as “atelectasis.” Additionally, deep inspirations and
the use of you “incentive spirometer” are essential.
You may shower after day 2 in the hospital, but it is important to keep the incision dry for 5 days. The nurse will help you cover your wound with Aquaguard to keep it dry or you may take a sponge bath.
Patients typically stay in the hospital for 4 to 7 days. Before your discharge, you will be provided with a list of “do’s and don’ts” and arrangements will be made for home health if necessary. You may need to be sent to an extended care facility after the hospital for 7 to 10 days depending on your assistance at home.
Once you arrive home
Continue to walk with the use of aids. Slowly increase your activity level.
You may shower, but do not soak in the bath or hot tub for 4 to 6 weeks.
Monitor your incision. It is common to have a small amount of blood and fluid
leakage, however, if there is persistent drainage contact the office. Additionally,
watch for opening of the incision, redness or warmth around the incision, or
fever greater than 101ºC.
You will need to return to the office to have your staples removed approximately
10 days after surgery.
Care for your incision by avoiding sun exposure. Once the incision is healed,
sunscreen can be used on the incision for 6 months to one year. This will help
decrease its appearance.
No driving for 4 to 6 weeks or until advised.
Typical recovery time is 3 months.
Looking after your new knee joint
Avoid jumping, high-impact sports or activities, sudden jolts to the leg, and
kneeling.
Control your weight by diet and low-impact exercise.
Take special precautions to avoid falls. Remove all scattered rugs and cords that
you might trip on.
Please contact our office if you are scheduled for any dental procedures,
colonoscopy or other procedure that introduces bacteria into your bloodstream
so that we may give you a prescription for antibiotics. The instructions for the
antibiotics are as follows: take the day before, the day of and the day after the
procedure (one tablet every six hours by mouth). This applies for at least two
years after your surgery date.