Never heard of skiers thumb before tbh. But personally I've broken both of them, the right one twice. It was aver 18 months ago, but it's still not 100%.
Injured left knee, was super lucky and didn't tear anything, so with rehab I was back in 3 months.
Why are ACL injuries so common? I hope I never tear mine but I like to think I do plenty of leg exercises to strengthen the surrounding muscles and tissues to withstand some pretty grisly falls.