Crippled by arthritis in his right knee, John Kerr, 60, former executive director of the now-defunct Major League Soccer Players Association, recently had knee replacement surgery. But instead of the standard three months' recovery, he will need half that time, thanks to a new minimally invasive procedure being done at only 11 sites nationwide, including the George Washington University Hospital. We spoke with GWU orthopedic surgeon Paul Manner about the surgery.

What's "minimally invasive" about replacing a knee?

We're still using the same prosthetic as always -- an orange-sized device comprised of ultra-light titanium and synthetic polymer. The difference is how we perform the surgery. Conventional knee replacement surgery requires an eight- to 10-inch incision running from the knee into the quadriceps muscle. With the new procedure, we spare the muscle, which saves the patient a lot of pain. The time spent hospitalized and in recovery is much shorter.

Is the procedure right for all knee surgery patients?

No. The patient of choice is an in-shape, fit and probably younger patient who can adapt to a rapid and more vigorous rehabilitation protocol. You're basically packing 12 weeks of rehabilitation -- including stretching and range-of-motion exercises to enhance flexibility and strength -- into six weeks. Patients need to view the rehab as a full-time job.

You're one of only a relative handful of doctors scrapping a proven 30-year-old technique in favor of the new one. If it's so good, why aren't more doctors doing it?

This is an emerging technology and the optimal techniques are still being refined. Plus, it's a hard surgery to do. I can do a conventional knee replacement in about an hour. The new procedure takes twice as long.

-- Rita Zeidner