sorry, you don't break your ankle but hurting your knee!
that's why I ski with a brace and the more you go on higher level the more people ski with braces!
Last year it was like a half hospital everyday in the skicenter when we take off our boots & braces
my first week of skiing was really a week of learning how to get up out of the snow most amusing, felt like I had some sort of vertigo, if I wasn't on the floor I'd be extricating myself from snowdrifts or off trees. The boots come away from the skis, yes. Unless you want them to on a busy, narrow bend, then your instructor has to try and stop everyone coming round and crashing into you while you struggle like a gonk...just adds to the fun!