Echoes,

I am late to this conversation, but have you tried a knee support for your knees? You can buy them at most discount stores in the pharmacy now (including Wal-Mart). I recently bought one for my son and there were several styles to choose from and most were less than $20. It probably isn't a long-term solution, but it may give you some support so you don't fall down the stairs until you can get to your doctor.

Good luck. I hope you feel better soon.