How do pediatricians treat their own kids with osgood schlatter disease?

They see a dcotor: It is considered poor medicine to treat your won family, as there is a lack of objectivity. Most doctors take their kids to doctors in the required field.

Same as patients: Depending on the severity, rest, immobilization or surgery. No different than any other child. Disease is the same, treatment is the same.

No Difference: Dr. Enriquez's answer is a good one. I would add physical therapy for the quadriceps muscle which can very helpful.