I think I've mentioned this before but we had a hamster who's front legs sort of fell off with a weird disease. My dad had to build extra little supports on his ramp so he could get up to his bed. And Stumpy was his name-o.
Anyway years later I was chatting to my dad about this and it turns out he didn't have a disease at all - my dad had made his cage which was wooden with a glass front and Stumpy used to try and burrow out, but he was burrowing against glass which wore his legs down. Deffo a design fault with the cage there (I remember he'd got the design out of a book so there was probably a whole host of Stumpys out there).
Tragic story eh