A 40-person surgical team used steel screws and plates to fuse together
Zion's old and new bones before delicately reconnecting his muscles, nerves,
tendons, veins and arteries.
Although he has several weeks of physical therapy ahead - he will soon
have the fine dexterity to pick up "smaller objects like Cheerios and
Legos".
An active young boy, Zion's hands and feet had to be amputated when he
was a toddler, after he contracted a serious bacterial infection.
But with the help of prosthetic legs, the schoolboy is able to walk, run
and jump like his friends.
He has also learned how to write using his forearms, and was already
able to feed himself and play video games before his transplant at The
Children's Hospital of Philadelphia.
Zion will need to take drugs which suppress the immune system for the
rest of his life - ensuring that the body does not reject his new limbs.
Doctors believed he was an ideal candidate for the operation because of
how he was already taking the anti-rejection drugs for a kidney transplant.
Dr L Scott Levin described Zion as an "incredible little boy",
adding: "This is a huge step forward in worldwide transplantation."