54 patients with mild (Kellgren-Lawrence grade I-II) knee osteoarthritis were randomized to a platelet-rich plasma injection with or without the addition of somatropin growth hormone. Patients were assessed for outcome on the Western Ontario and McMaster Univerisities Osteoarthritis Index (WOMAC) after 1 and 2 months following injection. Results demonstrated significantly better WOMAC score at 1 month in the PRP plus somatropin group compared to the PRP alone group, though difference between groups in WOMAC score at 2 months was no longer statistically significant.