I swore I would never put ds in a walker, because of hip damage?
But when dd came along, she was never into the same things he was, so I gave in a got her a walker. Which she loved. I'm not sure how you can have an accident with stairs, we only ever used in downstairs where we have hard floors, and I never left her in it for that long.
She did walk 2 months later than her brother though, but who can prove why that was??
It has to be one of those personal choice things.
We also have a wooden playpen, which I used for both of them, where they were also perfectly happy, which was the safest option. I put them in from an early age so they were used to it.