NEW YORK (CBSNewYork) — An accomplished junior cyclist received the shock of his life when the knee pain he thought was due to over-training was actually an aggressive cancer that threatened his ability to compete.

As CBS2’s Dr. Max Gomez reported, there was an innovative treatment which saved the boy’s leg and got him back on his bike.

The diagnosis used to spell a grim possibility — amputation. Then doctors developed chemotherapy that saved limbs and dramatically improved survival rates. But surgery to cut out the tumor was still needed, and that could have crushed Arnav Krishna’s Olympic dreams.

Few sports are as physically demanding and grueling as cycling, whether on the road or on the track. As a nationally ranked junior cyclist, Arnav trained constantly, so it wasn’t too concerning when he developed a pain in his leg.

“I though it might just be stretching pains or like, working out too hard,” he said.

A couple of doctors visits and several scans later, the diagnosis was devastating. Arnav had osteosarcoma in his leg, an aggressive bone cancer right below his knee.

His options weren’t great.

“I could get an artificial knee and maybe not be as competitive in cycling, or I could get a totally reconstructed knee,” he said.

Arnav was referred to the Children’s Hospital of Philadelphia, pioneers in limb-saving surgery. Doctors plotted a way to save his knee and his budding cycling career.

First came an intensive chemotherapy to shrink the tumor before surgery and improve his long term survival.

“There are microscopic pockets of osteosarcoma cells hiding in other places in his body, and so while the chemotherapy is important,” CHOP’s Dr. Naomi Balamuth said, “it’s also important to address the rest of him and make sure that if there are any lacking cells anywhere that they are killed with chemotherapy.”

Then came tricky reconstructive surgery to cut out the cancer and save Arnav’s knee which required bone grafts, plates, screws, and taking live bone from his other leg.

“He would have essentially a normal knee joint potentially and never need surgery again for the rest of his life,” CHOP’s Dr. Kristy Weber said. “So that was the home run, if we could get that to happen, but obviously we’re going to be cutting closer to the cancer. There’s that little risk there.”

It’s been a year and a half since surgery, and there’s no sign of the cancer. Arnav is actually back training on his stationary bike with his dream still in sight.

“My dream is to get to the Olympics but it’ll be a long ride,” he said.

Arnav had amazing support from friends, family, and his twin brother who’s also a ranked cyclist.

The Child-Life program at CHOP was also key in helping him through long, difficult stretches of chemotherapy. Arnav will be monitored for life for both his cancer, and the side-effects of the chemo.