Robert Fleetwood, 73, needed joint replacements in both knees, both to relieve his arthritis pain and to continue competing in athletic activities.

And thanks to medical advances, Fleetwood was able to go home the same day he had each knee replaced, in procedures spaced several months apart.

A knee replacement "changes your perspective on life. It makes you feel so much more alive and dynamic when you're not living with chronic pain that becomes debilitating," Fleetwood, of Stuart, Fla., said in a news release. "I'm very happy now."

People used to have to spend a night in the hospital following a knee replacement, but improvements in technology, surgery and pain management have made it possible to undergo the procedure in the morning and be back home by the evening, Dr. Martin Roche, director of joint replacement at Hospital for Special Surgery Florida in West Palm Beach, said in a hospital news release.

"We've come a long way in terms of being able to get people up and out of the hospital quickly, and that motivates them mentally, as well," Roche said.

Advances over the past five years that have led to outpatient knee replacements include:

· 3D CT scans that allow surgeons to plan highly personalized procedures beforehand.

· Surgical robotics and sensors that allow a high degree of precision and accuracy.

· Less invasive surgery that spares muscles and needs only small incisions.

· "Pre-habilitation" physical therapy that helps patients get stronger before their knee replacement.

Patients also have benefitted from longer-lasting nerve blocks and a pain management technique called multi-modal analgesia, Roche said. The technique uses various medications that target multiple pain pathways, and generally lessens the need for opioid painkillers.

Fleetwood says the surgery changed his life.

This year he participated in a 1K Navy SEAL memorial open water swim, competing with many people half his age. He came in second in his division (60 and older) and 30th overall out of about 150 swimmers.

Fleetwood also is running for exercise for the first time in more than two decades.

More information

Johns Hopkins Medicine has more about knee replacement.