OUCH! I broke my foot years ago, so I feel his pain. You didn't mention which bone was broken, so I'm not sure what to say. I'd say if it's an arm, go anyway, but if it's a leg or foot, maybe not, though you'd sure get on the rides faster if he needs a wheelchair. I'd talk to the Dr and see what he/she says. I was in a walking cast for my foot, so I could have gotten on and off rides rather easily, though I might have gotten a wheelchair for getting around because I still would have gotten tired and my foot sore if I tried walking all day, if I had gone while in my cast.