Lai Kuo-an, the director of osteology at National Cheng Kung University Hospital, says that this kind of congenital bone deformity occurs in about 0.8 percent of children, but it is still unclear why.
成大附設醫院骨科部主任賴國安指出，這種先天性骨骼發育不良的發生率為千分之八，病因至今未明。