NEW YORK (TIP): A 33-year-old man in US has undergone a ‘miraculous’ medical procedure to grow back his index finger which was chomped down by an overzealous horse while he was feeding the animal. Paul Halpern from Florida managed to save the severed digit and take it to the hospital, but doctors told him there was nothing they could do. Halpern then visited Dr Eugenio Rodriguez, a Deerfield Beach general surgeon who used an innovative procedure called xenograft implantation to regenerate the finger. Xenograft refers to transplantation of cells from one species to another. Rodriguez created a scaffold of Halpern’s missing finger, using tissue from a pig bladder, and attached it to the severed portion. The finger grew into the mold, generating new bone and soft tissue and a new fingernail. According to CBS Miami, Halpern had to apply pulverised pig bladder tissue to his wounded finger each day and cover it with a protective saline sheet. Rodriguez said the powder stimulates stem cells in the finger to regenerate, which causes the growth.