Download Minimally Invasive Knee Replacement

House Calls
October 22, 2008
Knee replacement surgery becomes less invasive
By Terry J. Weis, D.O.
Total knee replacement is a surgical procedure that decreases pain and improves the
quality of life in many patients with severe knee arthritis. Until recently, however,
rehabilitation from the decades-old, traditional way of performing this surgery was
almost as painful as the condition itself.
Traditional total knee replacements resulted in a hospital stay of three to five days, and
sometimes an additional stay in an inpatient rehabilitation setting before going home.
The recovery period during which the patient walks with a walker or cane typically
lasted from one to three months.
Compare that to a newer alternative ― a minimally invasive approach to total knee
replacement. Thanks to smaller incisions and less tissue damage, patients can
experience a much quicker and less painful rehabilitation. With the newer procedure
patients are able to walk to the bathroom the day of surgery, are out of the hospital
within 48 hours, and walking normally without assistance within days.
Minimally invasive (also called quadriceps-sparing) total knee replacement is great
news for today’s Baby Boomers, who are living longer and don’t want to give up their
active lifestyles just because their knees are failing them.
We’re seeing patients in their 50s and even 40s needing knee replacements. Orthopedic
surgeons now perform about 500,000 first-time knee replacements a year. A recent
American Academy of Orthopedic Surgeons study predicts that number could increase
by 637 percent in the next 20 years.
Saving the quadriceps, the knee’s most important muscle
The knee joint is the largest joint in the body. It is formed where the femur (thighbone)
joins the tibia (shinbone) and patella (kneecap). The joint is cushioned by cartilage.
In a total knee replacement, diseased bone and cartilage are removed from the femur
and the tibia, which are then resurfaced with cobalt chrome implants. A piece of plastic
is then locked onto the tibia, creating a new sliding surface between the femur and the
tibia, much like nature intended the knee to work.
With a minimally-invasive approach, the implant materials are the same. The difference
is how the surgeon gets in and out of the knee.
The quadriceps is the large extensor muscle on the front of the thigh. It’s the most
important muscle around the knee. Traditional knee replacement surgery requires
cutting through this muscle. A large 8- to 12-inch incision is standard.
But under minimally invasive knee surgery, the surgeon goes around the quadriceps,
not through it. Only a 4- to 5-inch incision is required. The quadriceps is stretched but
not damaged. This results in less postoperative pain, and a quicker return of motion
and strength.
Is your knee limiting your everyday activities?
If you have difficulty walking or performing everyday activities such as getting dressed,
it may be time to consider knee replacement surgery.
But first talk to your doctor about a conservative care physical therapy plan and knee
strengthening exercises. Steroid injections and a drug therapy called hyalgan injection
can restore the knee’s lubrication properties and delay surgery.
If a total knee replacement becomes necessary, consider an orthopedic specialist with a
high level of experience in performing the procedure. Eighty percent of knee surgeries
are performed by surgeons who only do an average of 20 knee surgeries a year.
Evidence shows that a higher level of cases performed by the physician and the hospital
leads to better patient outcome.
Terry Weis, D.O, is an SSM DePaul Medical Staff orthopedic surgeon who performs
minimally invasive knee replacement surgeries on DePaul’s Joint Replacement Center.
To contact his office, call (314) 291-7900.