Minimally Invasive Total Knee Replacement Surgery
By John T Dearborn, MD and Alexander Sah, MD
Institute for Joint Restoration and Research
Washington Hospital Healthcare System
More than 600,000 knee replacement surgeries are performed in the U.S.
each year, and that number is growing. According to a report from the
Agency for Healthcare Research and Quality, the annual number of knee
replacement procedures is estimated to grow by 673 percent, to 3.48 million,
by the year 2030. The good news is emerging technologies hold promise
for reducing the time required for knee replacement surgery, minimizing
surgical risks and providing more "personalized" knee replacement implants.
Traditional Knee Replacement
Traditional knee replacement surgery, in practice since the late 1960s
in the United States, has typically utilized an extensive, 8 to 12 inch
incision on the front of the knee. The actual size of the incision depends
on the size of the patient. The deep portion of the dissection divides
one of the quadriceps muscles in the thigh, called the vastus medialis,
and requires that the kneecap or patella, be dislocated and flipped over
on itself. Although the muscle heals eventually, the trauma which occurs
at the time of surgery takes months to resolve.
Minimally Invasive Knee Replacement
A handful of knee replacement specialists in this country have developed
specialized techniques and instruments to allow the same operation to
be done with a very limited incision and dissection. The skin incision
is typically three to five inches in length. More importantly, the muscle
in the thigh is left alone and the kneecap is simply shifted to the side.
Minimally invasive partial or unicompartmental knee replacement has been
performed using similar techniques since the late 1990s.
The advantages of this approach are many, including reduced pain, earlier
return of knee motion, and a faster recovery for the patient. The length
of stay in the hospital has also been reduced to approximately two days
for one knee and three days for two knees. These improvements have also
made knee replacement surgery available to many patients with health problems
severe enough to preclude the traditional procedure. Because the exposure
is less extensive, minimally invasive knee surgery is not applicable to
all patients, especially those with very stiff knees or large legs.
To gain more knowledge about joint replacement and related therapies, visit