Because the transplant bone is fused with one of his own bones, Adam's arm will grow as he grows older, reports CBS News Anchor Dan Rather.
Cadaver bones are commonly used in transplant surgery. But surgeons said this is the first time a live bone with its blood supply intact was combined with a cadaver bone so that the transplant would grow along with the patient.
Back in September, doctors removed most of Adam's humerus, the upper arm bone, because of a tumor the size of a grapefruit. The doctors then replaced it by taking the humerus from a dead child and fusing it with a piece of Adam's own fibula, the thin bone that runs from the knee to the ankle.
"We had a composite of Adam's fibula with its growth cartilage intact and a cadaver bone to add strength to the construction," says Dr. Michael Jofe, head of the 11-member surgical team.
Adam will have a full-size arm when he grows up, surgeons said. If he had received only a cadaver bone, he would forever have the arm of a little boy.
Doctors are pleased with Adam's progress and are optimistic about his future, reports Correspondent Deanna Lites of CBS News station WFOR-TV in Florida.
"We would expect over time his arm will function nearly normally. He should be able to do everything that other children his age and grown-ups are able to do," Dr. Jofe says.
While the Johnson family has endured more than most, they never gave up. They hope others will benefit from what their children went through.
"This is a divine intervention of God that he has given these doctors the wisdom, the ability to really look beyond and to develop whatever means they can to try and find some means as to how they can assist Adam," Adam's father, Anthony Johnson, told reporters Monday.
Adam will get physical therapy over the summer then be closely watched for the next five years, to make sure the cancer doesn't return.
Adam, who lives with his family in Nassau, Bahamas, hopes to become a professional basketball player. His father said he is overjoyed his son has a chance to lead a normal life.
In extremely rare circumstances, surgeons have successfully transplanted part of a patient's fibula to another part of the body, fusing it to whatever healthy tissue is left in the cancer-ravaged bone. The procedure was developed in Italy.
However, the fibula can fracture because of its narrow diameter.
In Adam's case, the surgeons decided to form a composite: They used part of Adam's fibula, with its blood supply and growth cartilage intact, and a cadaver bone to add strength and stability. The leg bone and cadaver bone are held together with a titanium plate.
The new procedure is "a spinoff of the techniques used i Italy. It's not anything necessarily new and different, but it's really a new twist on old ideas. The combination is really the key," said Dr. Mark Thomas Scarborough, a member of the surgical team and chief orthopedic oncologist at Shands Hospital in Gainesville.
Adam is the second sibling in the Johnson family to be diagnosed with this rare form of bone cancer, known as osteosarcoma. His sister LaToya Johnson, now 11, had her arm amputated in 1996 and replaced with an artificial limb.
Five months before Adam's surgery, the boy underwent chemotherapy to shrink the tumor. He lost his hair but never complained, doctors said.
"Adam did extremely well, in no small part due to his indomitable spirit and the support of his family," said Dr. Jofe.