My heart goes out to you, Burt...

Think you could use something like this with a kid's red wagon to rest your leg on and pile up debris as well?

http://www.thefind.com/garden/info-garden-scooter
(3rd and 4th row)

Or more pricey...
http://www.frontgate.com/deluxe-swivel-garden-scooter/422464?redirect=y

Hope your recuperation goes quickly and easily!

How's it going Burt?
I was wondering if you could at least rent a scooter. ....maybe one with wheels that could handle grass and dirt?
I can appreciate your situation and your frustration. I use a golf cart to get around the property, but I still have to get out of it to do things. My feet and knees are getting worse and worse, and I'm trying to think ahead, as to what I would use, to remain functional outside.
I hope you have found a solution.
Also......I might add that I hope you're looking into why your bones are breaking. Maybe you need more calcium, or something like that?
Best of luck to you in your recovery!