I won't call it "advice" but I will share my experience on this:
#2 daughter has a female who had this procedure about 6 years ago. Bella would go running with daughter & fiancee when they rode their bikes around the neighborhood and pulled up lame one day. The were referred to a team of surgeons locally (Nashville, TN) who claim a near 100% success rate for knee surgery. They said that the options for her were surgery or stay lame. They didn't think any appliance was going to help given the severity of her injury. So they bit the bullet, had the surgery and went through the 3-4 month rehab program and she was fine......for about a year until she tore up the other knee. The vet had warned them to save up their money because she would probably need the other knee fixed as well and he was right.
So, another surgery, another rehab and here we are. She seems fine...no apparent pain and no loss of mobility (aside from normal aging) and able to do all the things she used to, even if a little slower now, being nearly nine years old. All for the price of a good used car (+/_)
Was it worth it? Well, it wasn't my money, so it's not my call. What's a dog worth? On paper, it's a dead loss. She is a rescue, not purebred, representing a whole $100 investment up front, so spending $6K+ to restore her health is financial folly. But that's not how we dog lovers think so, yes - if the only alternative was to permanently crippled I'd have to say it was worth it for us . You would have to make your own determination on cost vs. benefit but we'd do it all again.
Your mileage may vary.