Can someone tell me if osgood schlatters is a chronic disease?

Yes,but will resolve: After growth plates close in adolescence, this condition will heal spontaneously.Most patients if treated conservatively with rest and nsaids will be pain-free within 12 months. This is a self-limiting condition but can last years if not treated appropriately.Some adults who had severe disease in adolescence will continue to have some knee pain (usually with kneeling) many years into adulthood.

No need to suffer: Osgood-Schlatter's is not a disease. It is actually a stress fracture of growth cartilage in front of the knee. There is some tendon damage as well. Standard treatment has been to restrict activity and wait until growth finishes. Frequently that will be adequate. If that is not acceptable, techniques to slow down activity are used to let it heal. Healing is usually 4-6 weeks.