More than 50 feet above ground, a wire rope extends from one tree to
another. High in the trees, seven-year-old Carter Mock fearlessly steps off a
platform and places first one foot, then the other, onto the wire. Holding
tight to hanging ropes for balance, he navigates across the wire to the next
It’s an impressive feat for anyone, but for Carter it’s extra special.
Just weeks earlier, he completed treatment for osteosarcoma
(a bone cancer), and he now has a prosthetic bottom left leg and foot.
Carter says navigating the wire rope is tricky, because he can’t feel
the pressure of the rope below his prosthetic leg as distinctly as he can with
his other leg. But that doesn’t deter him. On this warm August day, he expertly
completes all four levels of an aerial rope course at Mount Sunapee in New
Hampshire with remarkable speed and agility.
Two weeks after school had started in fall 2015, Carter started to
complain of a strange knee pain, and he developed a slight limp. After a
whirlwind of subsequent doctor visits – and an X-ray, MRI and then biopsy – his
family received his diagnosis: osteosarcoma.
Carter would need months of treatment, including chemotherapy and
surgery. He had two options for surgery. One was rotationplasty,
a unique procedure that would provide Carter similar mobility as a
below-the-knee amputation. Rotationplasty preserves the lower leg,
attaches it to the thighbone, then uses the ankle as a knee joint. After
surgery, he’d be fitted with a specialized prosthetic leg in which his
backwards foot would fit into a socket and his ankle would act as his knee. Once
healed, he could resume all types of physical activity again, even high-impact
Another option was limb-sparing surgery, which would maintain the
normal appearance of the leg. But the leg would never have the strength it had
before, and Carter wouldn’t be able to ski, skate, or run again.
It was an easy choice for Carter. He had no plans to give up skiing,
skating, baseball or activities like the aerial course challenge – so he chose
rotationplasty. After interviewing many surgeons at many cancer centers,
Carter’s parents chose Dana-Farber/Boston Children’s. They were impressed by
Mark Gebhardt’s experience – and even more convinced when another
rotationplasty surgeon told them outright: If it were my child, I’d go to Dr.
Carter received his first of many ongoing chemotherapy infusions in
October 2015. His surgery was in January, and physical therapy started just
days later. In April, he received his prosthesis. In June, he had his final
chemotherapy infusion, and his doctors cleared him to resume medium-impact
activities, including the aerial rope course. He hopes to get full clearance
for all sports – including skiing and hockey – in January.
Sometimes, Carter notices people stare at his prosthetic leg, and when
he still was in treatment some people gazed at his bald head. But here’s what
Carter really wants people to see in him: He is active and athletic. He can
complete the aerial course at Mount Sunapee without fear or difficulty. And
soon, he will ski and play hockey again.
September is Childhood Cancer
Awareness Month – and this month, Carter and other children at
Dana-Farber/Boston Children’s are sharing this message: We are more than you
see. Don’t focus on the side effects of our treatment – see who we really are.
Learn more, see more stories, and join the campaign at
In honor of Childhood Cancer Awareness Month, the children and teens at Dana-Farber/Boston Children’s are sharing this message: We are more than you see.
World class cancer care at the #1 children's hospital