Last year, Dara Torres became the first woman in her forties to swim in the Olympics.
She won three medals, but now she's suffering from a potentially career-ending injury.
CBS News medical correspondent Dr. Jennifer Ashton got an inside look into Torres' health problem -- her knees -- an issue that affects millions of Americans.
However, Torres decided to undergo a procedure that uses biotechnology to regrow her own cartilage cells by implanting them in her knee, with hopes of repairing it back to health.
As for another Olympic run, she's not ruling it out.
"I would like to be able to go for 2012," Torres said, adding "And I would like to be able to chase my daughter around without any pain in my knees."
Torres was reintroduced to the world in 2008, when at age 41 she trained for a record fifth Olympics, not long after the birth of her daughter Tessa. Her incredible comeback and stunning physique inspired baby boomers and young people alike. And last August, Dara brought home three silver medals from Beijing.
But just a year later, her future looked bleak.
"Some days it hurts to walk," Torres told Ashton. "Going up and down stairs -- forget it."
Dara is suffering from severe knee pain, caused by having little cartilage in her left knee.
Top surgeon Dr. Tom Minas, of Brigham and Women's Hospital in Boston, told CBS News her knee problem is currently a "career-ending problem."
Minas performed a radical procedure Autologous Chondrocyte Implantation (ACI) on Torres. First, he removed 10,000 cartilage cells from Dara's knee -- about the size of three Tic-Tacs. They were sent to a lab and grown for several weeks into 50 million cells.
During surgery, Dara's knee was opened up. Minas sewed a synthetic patch over the pothole where her cartilage was missing. Then, the 50 million cells were injected. If successful, they will harden and grow into healthy cartilage.
Six weeks after surgery, Dara was back in the pool.
So how was Torres' knee doing?
"My knee is doing great. I went in for my six-week checkup and they did an MRI scan and showed that the cartilage is growing."
However, Torres still can't kick when she swims, and she won't be weight training again until the middle of next year.
With 12 Olympic medals already in her collection, Torres says it's the rewards at home that are the most important.
"The competition, the swimming -- that's so not even an issue compared to trying to be there for your daughter," she said.
But with her newly-repaired knee, Torres -- now 42 years old -- isn't ruling out a run at the Olympic Games in London.
She told Ashton, "I don't know what my body can do. I don't know if it will hold on for two years going for 2012, but why not give it a try."
Ashton said the ACI procedure costs about $60,000, most of which is covered by insurance. However, she added there is a more advanced procedure undergoing trials right now which is less invasive, and recovery time for those patients will be much shorter.
But could ACI be a benefit to you?
Ashton said,"It actually could be for the weekend warrior. When we spoke to (Dr. Minas) he said, yes, of course Dara is the exception and she is amazing in terms of her ability, but he's actually seeing a lot of people who are in their 30s and 40s (who have) just worn down the cartilage in their joints. And this we should mention is potentially really exciting as a last effort before someone goes on to a total knee replacement. It is amazing."