182 patients with knee osteoarthritis (OA) were randomized to one of four groups: PRP-3 (3 injections), PRP-1 (single injection), hyaluronic acid (HA), or saline injections. All active treatment groups (PRP-3, PRP-1, HA) demonstrated significantly more favourable EQ-VAS pain scores and IKDC scores compared to saline injections.The patients treated with three injections of platelet-rich plasma (PRP) achieved significantly more favourable scores on the EQ-VAS for pain and IKDC subjective scores compared to those treated with a single injection of PRP and HA injections. Subgroup evaluations indicated that the same result was observed in patients with early OA, but there were no significant differences in these scores between the active treatment groups (PRP-1, PRP-3, HA) in patients with advanced OA.