PRP injections versus viscosupplementation for early knee osteoarthritis: a randomized double-blind study

Objectives: The influence of growth factors (GFs) on cartilage repair is not yet widely studied and its application in clinics is still experimental. Platelet Rich Plasma (PRP), a blood product rich in GF, is a promising support for treating cartilage defects. Aim of this study is to evaluate and compare the efficacy of PRP and Viscosupplementation (Hyaluronic Acid—HA) injections for the treatment of chondropathy or early osteoarthritis (OA) of the knee. Methods: 150 patients were enrolled: 72 were evaluated at 6 months follow-up. The study involved patients affected by chondropathy or early OA. All patients underwent an autologous blood harvesting, then 36 patients were randomized in the PRP group and 36 in the HA group. A cycle of 3 weekly injections was administered blindly. All patients were clinically evaluated at the enrolment, 2 months after the treatment and at 6 months follow up. IKDC, EQVAS, TEGNER and KOOS scores were used to clinically evaluate the patients. Adverse events and patient satisfaction were also recorded. Results: No complications like infection, marked muscle atrophy, deep vein thrombosis, fever, haematoma, tissue hypertrophy, adhesion formation or other major adverse events occurred among study subjects. Only minor adverse events were detected in some patients, as mild pain reaction and effusion after the injections, in particular in the PRP group, but they lasted for no more than a few days. At the follow-up evaluations, both groups showed a significant improvement in terms of function and quality of life. The preliminary comparison between the outcomes of the two groups showed a not statistically significant difference, but with a trend slightly favourable for the PRP group at 6 months. Conclusions: PRP is a simple, low cost and minimally invasive approach to treat chondropathy and early OA. The clinical results of our study are encouraging and suggest this method may be used to treat the degenerative articular pathology of the knee, leading to results at least comparable with those of HA. Long-term results will confirm the reliability and evaluate the durability of this promising procedure.