Knee osteoarthritis (KOA) is a degenerative joint disease leading to pain and disability for which no curative treatment exists. Intra-articular (IA) therapies are part of this multimodal approach and are approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA). Platelet-rich plasma (PRP), hyaluronic acid (HA), and corticosteroids (CS) have been increasingly used in recent years to treat KOA.
To determine whether IA-PRP was superior to IA-HA or IA-CS administration routes in these patients.
In this trial the patients were randomized to IA-HA (2 ml/week, for 3 weeks), IA-CS (1 ml) or IA-PRP (3 times, 4 ml, every 3 weeks) groups. The outcome was assessed using the Western Ontario and McMaster Universities (WOMAC) score prior to the first injection and then at 3, 6, 9 and 12 months. Pain was evaluated by a visual analogue scale (VAS) prior to treatment and after 12 months.
In this study 120 patients were randomized into 3 groups. There was a significant improvement in all scores (WOMAC, VAS) in each group compared to the pretreatment values (P < 0.05). The mean WOMAC scores for the IA-HA group from pretreatment to 3, 6, 9, and 12 months were 47.23 ± 5.37, 25.02 ± 4.98, 26.38 ± 5.20, 27.86 ± 4.34, and 30.64 ± 8.36, respectively. Similar improvements were noted in the IA-CS and IA-PRP groups. There were no significant differences in the WOMAC scores between the 3 groups 3 months after treatment (P > 0.05) but IA-PRP showed significantly lower scores 6, 9 and 12 months after treatment (P < 0.05).
Intra-articular PRP injections into the knee for symptomatic early stages of KOA are a valid treatment option. The clinical efficacy of IA-PRP is comparable to that of the IA-HA and IA-CS forms after 3 months and the long-term efficacy of IA PRP is superior to IA-HA and IA-CS.