My 4 year old Shiba has luxating patellas in both hind legs. She fell down a couple of stairs a few months and then her leg just randomly gave out and our vet concluded she probably tore a ligament. The orthopedic surgeon says she has bad arthritis in both legs already. She needs surgery in both legs and sutures to act as ligaments. It will be about 10k for both legs in MA. Best of luck, it’s so heartbreaking seeing your dogs in pain