I have 2 with a grade 4 in one and a grade 3 in the other and one with both knees a grade 3 and have not and will not have the surgery as long as they are not showing any pain or discomfort. I control it with keeping their weight off and have been for the last 3 years. They haven't popped out in 3 years
One is 7 the other is 6 and the other is 4 years of age
If you keep the weight off and continue to supplement and exercise I think you can do well without the surgery. I know it's worked for my 3
Donna