Suddenly after walking all the time, My Roxy started to limp

. After waiting a month we went for x-rays & then to a specialist. It was determined that she has MPL-Grade 3 in both legs. Think back, she has always been bow legged since a pup. She is only limping in one and doesn't seem to be in pain. I see it in her eyes, she's a trooper. I am feeling so awful. I now have her scheduled for surgery this Friday, 5/15 and in some fear having 2nd thoughts. Both legs are being done as I don't want her to go through this twice. Am I doing the right thing?? Are there any other treatments that are better?? Any Holistic ?? The glucosimine and chondroitin are not doing anything.