Osgood-Schlatter disease is relatively common condition in adolescents. Classically, its pathophysiology is considered to be a traction apophysitis of the proximal tibial tubercle, which is caused from overuse. However, there is growing evidence that the underlying pathology of Osgood-Schlatter disease is tendinosis rather than apophysitis. Tendinosis is described as a degeneration of collagen following chronic overuse of a tendon. Examination of ultrasonographic and magnetic resonance imaging of tendinosis exhibits many similarities with the imaging of Osgood-Schlatter disease. Further research should be conducted in implicating tendinosis as the pathologic mechanism in Osgood-Schlatter disease. This paper provides a brief overview explaining the basis of tendinosis as the basic pathophysiology underlying Osgood-Schlatter disease and explores the related treatment implications.