Hi there, sorry that your little one is possibly facing lp surgery. We went thru it with Hot Rod. He was about 1 1/2 and his poor leg was bowed outward. He did not want to go for the walks that he loved to. He was at a grade 3.
Long story short, I am glad that we went thru it, but we didn't have much option as he needed it due to his leg being bowed outward. I seconded guessed myself for the first few days and then for the next 2 weeks. I couldn't relax until I got the phone call that the surgery was done and he was waking up.
We were not allowed to see him after surgery as they felt it would upset him.

I was able to call to check up on him however and they were very understanding, even at the 3rd phone call for the night. lol

My anxiety, and so will yours, dropped 85% when I got the phone call after his surgery. Yay!
Did your vet go over supplements at all? We are now on Dasuquin. Maggie May has been diagnosed with mild grade 2 in both knees but the vet feels as though she is okay and does not need surgery at this point in time. To see her, you would never guess she had loose knees although you can hear them pop sometimes but she's always running and jumping without any hesitation or pain.
I have soft collars available if you should wish to look at an alternative to the plastic cone collars. Just click on the 2nd portion of my signature. Best of luck with your decision. Please feel free to pm with any questions.
We were able to get CC and they were super quick and easy to work with.
Hugs, Bo