older bilateral PFFD

HI! I'm a female , 3'10" with bilateral congenital absence of femurs, patellas, and illiums. I stopped using prostethics years ago, as I couldn't handle them. I'm getting incontinence from a 'dropped bladder' My urogynocologist isn't sure how to insert a 'sling' with all my missing bones. She inserted needle in my ankle to thread up toward my heart but at my waist, it went in directions she didn't see before and stopped. Does anyone have suggestions on how I can get a 'sling' proceedure. Thanks for any help you can give me.