POOR Baby !!
I hope the surgery goes well - it sounds like he must have really landed hard but it doesn't take much for these little guys to hurt themselves -
you can use a stroller for him to keep him still while he's healing - and then when his leg starts getting better and he's moving around - STEPS to the places he likes jumping from ...
all the best to you - I hope your mom's ok also - I'd have freaked out too ....GOOD LUCK !