First, Welcome to GT, and Humphrey is a real doll!
I'm sorry you're going through this, it must be pretty scarey. We've had no broken bones here, but my Lou dislocated his hip last October, had ortho surgery, and has had a very long recovery, he's not done yet! - a break would have been healed a lot more quickly, I'm told. The hardest part is keeping them amused, so I hope your boy likes interesting treats! We found that things like recreational bones, or peanut butter mixed with dog biscuits, stuffed into a kong and frozen kept him busy. But I don't know if you guys have kongs over on that side of the puddle.
In any case, I'm sending prayers for a rapid and uncomplicated recovery for your boy.