Langley junior Maureen Marsh returned to the court two years after being treated for bone cancer. (John McDonnell/THE WASHINGTON POST)

The explanation sounded believable enough: The nagging pain that Maureen Marsh was experiencing in her right knee two years ago as a 14-year-old freshman was likely because of growing pains. But when the athletic trainer at Langley High, Nathan Welever, saw the small bump on the side of Marsh’s leg, he suggested that the volleyball player get it checked out.

What doctors found was a small cancerous tumor at the end of Marsh’s femur — bone cancer cells collectively referred to as osteosarcoma, a rare form of cancer that is more prevalent in children and teenagers. Marsh underwent limb-salvage surgery and endured intensive rounds of chemotherapy. Two years later, she is back on the court. The 6-foot-1 junior starts on the right side of Langley’s front line and has made her presence felt on a Saxons team that advanced to the Virginia AAA Northern Region tournament.

“She has absolutely defied every limitation that has been put in front of her, in her own quiet, sweet way,” Marsh’s mother, Carol Phelan-Marsh said. “The doctors said she’d probably never play again, and they’re delighted for her to prove them wrong.”

Marsh began chemotherapy Nov. 2, 2009. Two months later, she had surgery to replace her right knee joint and remove five inches of her right femur, which was replaced by a titanium prosthetic, custom-fitted to keep her two still-growing legs as even in length as possible.

“I was somewhat skeptical when she explained how determined she was to get back to the [athletic] level she was at before,” said Robert Henshaw, the surgeon who removed and replaced Marsh’s knee joint. “Generally, patients should have no difficulty walking after the surgery, but to perform a high functioning athletic sport that requires so much mobility and stress on the knees, it’s a rare patient that’s able to do that comfortably.”

Following a bone cancer diagnosis, Langley junior Maureen Marsh underwent limb-salvage surgery in which her right knee joint and five inches of her right femur were replaced with a titanium prosthetic. (Courtesy of Marsh family/Courtesy of Marsh family)

It wasn’t easy to get through those nights during the spring of 2010, when the machines at Children’s National Medical Center kept Marsh awake or when she had to ask for her mother’s help just to get up from the living room pull-out couch. The medicines she took ravaged her appetite. Marsh rarely asked her friends to visit, and they rarely could with the hospital on lockdown during the swine flu epidemic. “I didn’t like having to be so dependent on people,” Marsh said. “I didn’t really know what to do with my time.”

But once the eight grueling months of chemotherapy finally ended, Marsh spent as much time as she could trying to work her way back into volleyball shape.

With the help of an aggressive physical therapy regimen, she surpassed her doctors’ goal of 90-degree mobility in her knee — she’s now at 126 degrees and counting — and rejoined her teammates for light practices her sophomore year.

But that wasn’t enough.

“I have a high standard for myself, and even though the doctors are happy, I was never happy with how much I was bending my leg,” said Marsh, who wears only kneepads to protect her knees when she plays. “I still wanted to be able to do more and be really mobile.”

By the spring, she was seeing minimal action late in matches with her club team, and by the start of high school practice in August, Marsh was ready to regain her starting spot with the Saxons, with one catch — she had to shift from her natural middle blocker position to the right side.

The adjustment has been challenging. Marsh’s limited side-to-side mobility makes her a liability in the center of the court and limits her ability to time blocks effectively alongside the team’s hitters. She also has difficulty bending and squatting, two motions essential for players in the back row.

“I know I need to work on my blocking,” said Marsh, a self-described perfectionist. “I feel like I’m jumping really high, but in reality, it’s just a few inches. And I need to work on my timing. It’s so different in my head than in reality. I just hope I can start to do more to help the team because right now I just feel like I’m sort of slow.”

Whether she realizes it or not, Marsh has already helped her team, with her play and her resolve to rejoin them — a determination her teammates say has been an inspiration. “She’s been so brave throughout her recovery,” said junior Madeline Osburn, who took over Marsh’s starting middle role. “She’s so determined to come back, and it’s really shocking to everyone how fast she’s been able to do it. Maureen has a way of bringing the team together, and we’re very grateful to have her back.”