49 patients with higher grade cartilage lesions (Outerbridge grade III-IV) and mild knee osteoarthritis (Kellgren-Lawrence grade I-II) were included in this study. Patients were scheduled for arthroscopic microfracture and randomized to the procedure with or without the application of platelet-rich plasma (PRP) intraoperatively. Follow-up was conducted for 2 years postoperatively for pain and functional outcomes. Additionally, second-look arthroscopy was performed in a subset of 10 patients from each group between 4-6 months postoperatively. Results at 2 years demonstrated significantly lower pain scores in the PRP patients compared to control patients, as well as a higher rate of IKDC grade A (ie. normal) knee examination. No significant difference in Lysholm score was observed between groups at 2 years.