Anatomy of the Knee
The knee joint is where the femur bone connects to the tibia and fibula. On top of articular cartilage rests the patella which forms the kneecap. The patellar ligament connects the patella to the tibia at the tibial tuberosity. The quadriceps muscles are on top of the femur and superior to the patella which make up your thighs. Underneath the femur are the hamstrings which connect to the fibula. The anterior cruciate ligament commonly known as the ACL connects the bottom of the femur to the top of the tibia and the posterior cruciate ligament (PCL) does the same but behind the ACL.
Restructured Knee Joint
To prevent Osgood-Schlatter from impacting so many young athletes I would replace the patellar ligament which is tough and not super flexible with elastic cartilage. This would make the joint be able to bend more without pulling on the tibial tuberosity causing irritation. The downside to changing this anatomy is that the elastic cartilage would be less strong and the patella would have less support meaning it could move more and dislocations of the knee would be more common.