What is the definition or description of: osgood schlatter disease?

Apophysitis: This condition happens in the adolescent/pre-adolescent population. It involves anterior (front) knee pain where we have a small protrusion (about 6cm below the knee cap lower aspect). It happens because there is too much stress on that area of the bone that still grows (growth plate/apophysis). Most of the time it will resolve with rest.

Osgood Schlatter: Osgood-schlatter is a condition involving a portion of the tibial growth plate at the insertion of the patellar tendon. It is associated with tight quadriceps (especially the rectus femoris). There can be a painful fragmentation that occurs at this area. The best treatment is stretching, nsaids and rice. It resolves when the growth plates close.