My dog has a luxating patella from blunt trauma. Do I have the surgery?

I have a 2 year old Bichon Frise. He ran after a rabbit while on his leash last Sunday (6 days ago). I took him to the vet and he put him on Previcox. He has been walking okay for the last three days but today he yelped in the kitchen and laid down. The vet said it is "2 steps forward, one step back" with the healing process. I worry my Bichon will never run again. When he does walk on 3 legs, he does so for a few seconds and then can walk on all 4 legs. It looked like he was getting better but then today he let out a yelp. I know these luxating patellas don't really heal but it was due to trauma not heredity so I thought maybe it would. Should I start looking into surgery for him? I'm so upset.