Ah come on! Got to be worth asking your son to take one for the team and break his other leg so you can go back with a proper tool kit..... he's young, he'll get better
Hope he feels better soon. I had my leg in full plaster from ankle to nuts for six weeks earlier this year and it's not a very nice experience bless him. Trying to get up the stairs before shatting myself and then perching on the rim of the toilet seat was the highlight of it all