This little boy is the first person in the world to get a double hand transplant

Eight-year-old Zion Harvey can't wait to pick up his little sister with his new hands.

Both of Zion's hands were amputated when he was a toddler. But the 8-year-old Baltimore native just became the world's first child to receive a double hand transplant.

The 10-hour operation took place earlier this month at Children's Hospital in Philadelphia.

Zion still has a lot of physical therapy to go, but he's already looking forward to showing off his new limbs to his sister. "My favorite thing [will be to] wait for her to run into my hands as I pick her up and spin her around," he told NBC News.

When Zion was two years old, he developed a life-threatening bacterial infection that required both his hands and feet to be amputated. He also had a kidney transplant (his mother donated the organ). Since Zion already has to take drugs to suppress his immune system from attacking the kidney, he was the ideal candidate for the hand transplant, doctors said.

The boy is pretty independent - before the transplant, he was able to feed himself, walk and run using prosthetic legs, and play video games. But he told NBC he'd always wished for a pair of hands.

The surgery itself involved attaching the bone, blood vessels, nerves, muscles, tendons, and skin of a pair of donor's hands and forearms to Zion's.

Before the operation, the 40-person transplant team, led by Dr. L. Scott Levin an orthopedic surgeon at Penn Medicine and director of the hand transplantation program at Children's Hospital, practiced extensively on cadavers.

"The success of Penn's first bilateral hand transplant on an adult, performed in 2011, gave us a foundation to adapt the intricate techniques and coordinated plans required to perform this type of complex procedure on a child," Levin said in a statement.

The first double hand transplants on adults were performed in 2000, by surgeons in Austria, and the first one in the US was done at the University of Pittsburgh Medical Center in 2009. Since then, more than a dozen have been performed. But no child had received a double hand transplant until now.

Doing the surgery on children is especially challenging, because they have smaller bones and anatomy, and are still growing, doctors say.