Introduction: Knee pain is one of the most frequent musculoskeletal symptoms in young physically active males. In some cases, it is very painful, can be hard to treat, and often lead to heterotopic ossification of the patellar tendon. To our knowledge, there are no reported cases of remission of ossification after clinical intervention. Case presentation: A 13-year-old Swedish boy with a 3-year anamnesis of severe Osgood-Schlatter with significant ossification of the patellar tendon at the point of tuberositas tibiae, was treated with injections of Liquid Platelet-Rich Fibrin (C-PRF) and Heat-Coagulated Albumin Gel (ALB-PRF) using a horizontal centrifuge system. He recovered and presented a near complete remission of ossification of the patellar tendon two months after treatment and could return to sport after a 3-year break. Conclusion: This case raises the hypothesis that Liquid Platelet-Rich Fibrin and Heat-Coagulated Albumin Gel may be an effective intervention in the treatment of Osgood-Schlatter disease. Further research is required to test this theory.

Keywords: Osgood-Schlatter, PRF, ALB-PRF, PRP.