Termite my Yorkie needs your help

My sweet little Yorkie can hardly walk...Termite has luxating patellas in both rear legs...at only 7lbs, she wants to run and climb stairs like she used to...I tried a leg brace on her but that is only a temporary solution...I got some quotes for an operation and the estimate is $3500-$5000. I am a senior on a low fixed income...Please Help...the little stairs I had to help her climb up onto the bed or sofa are not useful to her anymore...She just stands or sits looking up at me to pick her up..I give her liquid glucosamine to help with joint pain...Yorkies live quite a long time usually 15yrs, so Termite is only young...She is the light of my life and therapeutic to my own aches and pains...Luxating patella means that at stage4 her knees are dislocated most of the time and its is painful for her to walk, so she spends most of the time immobile. The operation would correct this problem and enable her to be a more active dog...She used to play with toys but now she just lies on them...Thank you for any donation to help her...