If ossicles occur within the disease pattern of Osgood-Schlatter disease (apophysitis tibialis adolescentium) the duration of the complaints is usually extended to twice the normally expected period. Their shape and location influences the clinical course of the disease. Surgical removal of these ossifications is the therapy of choice if the complaints persist for a relatively long time. With regard to conservative treatment it has been shown on the basis of the duration of healing that functional therapy with an expansion of the ischiocrural musculature is preferable to immobilization of the joint. We consider functional treatment to be justified even if there is an increased formation of ossicles on non-immobilization of the joint, since such ossification occurs with only 20-25% of all cases of Osgood-Schlatter disease and the duration of the complaints is markedly less enhanced than with immobilization measures. As far as the sportsman is concerned, this entails only brief loss of training and the possibility to avoid muscular atrophy of the affected leg by means of physiotherapeutic exercise.