Posted: 07/30/2010 - Every year, 400 children in the United States get osteosarcoma. It's rare, but it's also the most common bone cancer in kids and usually strikes in the leg, just above the knee. In the most challenging cases, amputation is the only way to stop the cancer. Now, a new kind of bone implant is helping to save limbs… and lives. Melissa Medalie has the story.