My 10 month old had full body xray which shows a healed fracture to his proximal tibia, he showed no pain or swelling during the time frame, is this even possible to carry on standing on it?

"Healed" fx: I'm not sure why a 10 month old should be exposed to full body irradiation. Regardless, the study suggested a "healed" fracture." when was there any documented trauma? He should be able to ambulate.

Fracture?: Whomever ordered the full body xray should review the results with you. Since your child is young there is a very good chance that the "fracture" is simply an open growth plate which is completely normal. I would go back to whomever ordered the imaging and ask questions.

See a peds ortho: 10 month olds should not break a tibia without a reason. It may just be a 10 mo old being a 10 mo old (crawling, cruising, twisting and falling). This is even called a "toddler fracture." there are more concerning reasons too: brittle bones, problem he was born with, etc. A pediatric orthopaedic specialist would be best able to evaluate him and answer all questions or worries.