Total Knee Replacement
When a patient suffers from severe arthritis in more than one compartment of the knee, a total knee replacement
is performed.
Total knee replacement surgery, or knee arthroplasty, is a procedure that can be performed in order to replace the
damaged articular surfaces with an artificial joint. This joint consists of a plastic tibial implant and a metal
femoral implant that are cemented to the bone surfaces, replacing the arthritis-affected joint surfaces. A plastic
"button" is used to replace the articular surface of the patella, or kneecap.
This procedure is one of the most successful in the field of Orthopaedic surgery, not only relieving the pain patients
experience in the arthritic knee, but also correcting the alignment and allowing the joint surfaces to once again move
fluidly within the knee.
A knee replacement is performed through a straight incision on the front of the knee. The bone and cartilage at the
end of the femur (thigh bone) and top of the tibia (leg or shin bone) are removed with special tools that create an
accommodating surface for the implant. The metal femoral and plastic tibial implant is then placed and serves as the
new knee joint. Cartilage on the kneecap is replaced, with a cemented plastic prosthesis.
Postoperative Management after Total Knee Replacement
As in most surgeries on the knee, the postoperative rehabilitation is of the utmost importance and Dr. Sanders starts
the afternoon following surgery. A patient will remain in the hospital for four to six days days, immediately beginning
an accelerated rehabilitation program.
Avoiding Blood Clots
The risk of a blood clot traveling to the lung and causing death is high after total knee replacement. All patients
undergoing lower limb surgical procedures receive Lovonox in the recovery room. This is an anticoagulant, or blood
thinner, used to prevent blood clots (thrombosis). Dr. Sanders eliminates even the slightest risk this condition with
the anticoagulant. Patients continue to take Lovonox twice a day for 10 days post surgery.
Medication
Patients are given Torradol, a non-narcotic pain medication also administered to the patient in the operating
room and continued by vein while in the hospital. After discharge, it is taken by mouth four times per day for
five days post surgery. This reduces the need for stronger narcotic medications. Patients should also take two
Tylenol tablets every six hours around the clock for preemptive pain control. Two tablets of Tylenol PM (a
preparation that includes Benedryl) should be used at night instead of the ordinary Tylenol, as this facilitates
sleep.
Patients are also ordered a mild to moderate narcotic analgesic (Class 3 medication), as well an IV
(Class 2) narcotic medication. These should be used sparingly. These medicines frequently cause side effects such
as nausea and/or constipation. The preemptive pain control drugs such as Torradol, Tylenol, and Tylenol PM prove
to work just as well as the narcotics.
Preventing Infection
Infection is a serious complication following Total Knee Replacement, so patients are given antibiotics by
vein at the time of surgery - which reduces the risk to less than one percent. Following this, no further
antibiotics are necessary. Patients are responsible for the care of their wound and prevention of infection.
Good personal hygiene and proper wound care are of utmost importance.
Wound Care
Patients should expect some blood drainage through the dressing. This is normal and should not be a cause
for alarm. We do not reinforce the dressings, as it inhibits knee motion.
The drains, which were placed into the wounds during surgery to control swelling and prevent stiffness, are
removed the second day following surgery. Compressive stockings (TEDS) and Plastizote pads are placed on the
legs and may be removed in order to shower the day after surgery. The Tielle Bandages are left over the wounds.
Following a shower, the Plastizote pads and compressive stockings are replaced. Although the Tielle Bandage
would be best left on for five days, patients should not become alarmed if it falls off. The wounds should
simple be washed with soap and water, followed by peroxide on a gauze pad, if the steristrips have fallen
off as well.
The fifth day following surgery, the Tielle Bandages may be removed in order to shower. In addition, the
operative area may be washed. Attempts should be made to maintain the steristrips. If they have fallen off,
the cuts can be washed in a shower with ordinary soap and water and then Peroxide on a gauze pad. The wounds
are then left open, if they are dry. If they are seeping, they are covered with a gauze pads. For the first
ten days, the compressive stocking remains on and only showers are allowed. Bathing in the bathtub should be
avoided the first ten days.
Preventing Swelling and Excessive Pain
A Cryo/Cuff® (cold therapy device) is placed over the compressive stocking
on the recovering limb the first day post surgery and remains for the next week to further minimize the amount
of swelling and pain. The Cryo/Cuff® should be removed only when performing active knee flexion exercises.
Otherwise, it should be maintained at all times. With less swelling and pain, motion is regained faster. The leg
is then elevated on a Continuous Passive Motion device (CPM).
The best way to keep pain and swelling manageable is almost complete bed rest and elevation of the recovering leg
in the CPM device for the first week, and after release from the hospital. Patients are allowed to stand with
crutches or a walker for gait training, taking full weight on their new knee. Otherwise, limited trips to the
bathroom are acceptable for short (repeat, short) periods. Leaving the house is best avoided the first week.
Regaining Mobility and Strength
Phase One
The Recovering Knee, Day of Surgery through Postoperative Day 14
Movement is one of the most important elements in a rapid recovery and return to full mobility. A number of
different devices and exercises are introduced to patients through an accelerated program in the advancement
towards recovery.
Established in three phases, the first device used in this rapid recovery process is the CPM, which takes the
knee through the range of motion from hyperextension to 110 degrees. This is begun the same day the surgery
takes place to help maintain Range of Motion and keep the knee higher than the heart, in order to diminish
swelling. The CPM machine should run for 40 minutes on the hour.
The next ten minutes of the waking hour is spent on Active Range of Motion exercises for ten minutes on the
hour. The knee is brought through a range of motion from hyperextension to almost complete bend - such that
the heel approaches the buttock. In order to accomplish this, the knee is fully extended by placing several
folded towels under the heel, and a single towel held by both hands under the forefoot. As toes are pulled
towards the head, assisted by the towel held in both hands, the patient pushes the back of their knee down
toward the bed. This enables physiologic hyperextension, which is important for a return to normal activities.
For knee flexion, the towel is then put over the toes and held with both hands. As it is pulled, the knee
bends to a point where the heel approaches the buttock.
In the final ten minutes of the hour, patients work on active quadriceps exercise. To complete this exercise,
the foot rests on a pillow, with nothing under the back crease of the knee. Patients will attempt to push the
back crease of the knee down towards the bed, move the toes upward towards the head and lift the leg ten inches
straight up into the air. It is maintained there for a count of five. This exercise is repeated 10 to 25 times.
Following completion of this exercise, the CPM is replaced and set to operate from hyperextension through 110
degrees flexion - and the cycle is repeated.
Mealtime Exercises - in the first week while in bed
During mealtimes, the CPM is removed and the patient sits on the bed allowing legs to dangle off the side
at a bend of 90 degrees. Following meals, an active exercise is done by actively extending the recovering limb
for ten reps.
The second half of Phase One: Postoperative day 8 through 14
On the eighth day following surgery, patients are generally able to resume regular sedentary activities and
have a nearly normal gait with or without a walker or crutches. The length of time that patients use a walker
or crutches is dependant on the patient's age and general physical health. Patients should continue
their active exercises four times per day. A follow-up appointment is made at this time.
Phase Two
Postoperative Day 15 through 28
At two weeks, patients continue their exercise program by adding the Step Box. This simple device is used
for the performance of closed chain knee extension exercises, beginning with four sets of 25 reps of two-inch
excursions until fatigue each day, progressively increasing until 50 reps can be performed. The same routine
is then continued with a four-inch excursion. After the same goal is reached, the excursion is increased to
six, then eight inches. Patients must remember to do at least four sets per day. The patient may start to
work the stationary bike and/or the Stairmaster in the routine, as well as continuing the Step Box at increasingly
longer excursions through the end of the fourth week.
The team of certified trainers at the Sanders Clinic then develop an ongoing
exercise plan and assist in the rehabilitation, in order to continue strengthening the injured area and
surrounding muscle groups. This ensures the best postoperative results.
Phase Three
Postoperative Day 29 until discharge from active treatment
Patients schedule another follow-up appointment with Dr. Sanders one month after surgery. Certified trainers
work one-on-one with the patients to continue a Reconditioning Program.
They establish an exercise routine that can be done both at home independently, as well as at a gym or clinic
under supervision. During months three and four, patients may begin returning to sports at a restricted level.
And through the remaining year, patients are periodically evaluated with strength and measurement tests.
The long term
The loosening and wear of the prosthesis has been a problem over the years. Many innovations in the design
of the Total Knee Prosthesis have been introduced only to be withdrawn when they have shown to cause more
problems than solutions. These have included bone ingrowth prostheses, which did not use cement, and metal
backed tibial trays, and a asymmetric metal backed patella prosthesis. Controversy has existed among surgeons
regarding whether or not the posterior cruciate ligament should be maintained or removed. Those prostheses in
which the posterior cruciate ligament is removed last longer.
Dr. Sanders uses a prosthesis system that has been shown the best long-term results. The vast majority of
Total Knee Replacement patients with this prosthesis system have shown to retain their original prosthesis for
over twenty years. This design, made by several companies, is known as a Posterior Stabilized Prosthesis; which
serves as a substitute for the posterior cruciate ligament, is fully cemented, has an entirely polyethylene
tibial tray, a metal femoral prosthesis, and a simple polyethylene patella button.
* Patients undergoing joint replacement procedures should always inform physicians before future procedures
are done. In some cases, such as dental procedures and colonoscopies, antibiotics are required in advance in
order to prevent the bacteria introduced into the bloodstream from infecting the prosthesis.
