Intra-articular platelet-rich plasma injections were not superior to viscosupplementation for early knee degeneration

This report commend Filardo et al. on their recent research entitled “Platelet-rich plasma intra-articular knee injections show no superiority versus viscosupplementation: a randomized controlled trial”. The aim was to assess the benefit provided by platelet-rich plasma (PRP) injections to treat early knee joint degeneration in comparison with hyaluronic acid (HA) injections. The authors conducted a randomized (allocation concealed), blinded (clinician, patients, and outcome assessors), controlled trial with 12 months of follow-up in a specialized center for orthopedics. It was a well-designed study with proper statistical analysis. A total of 192 patients with unilateral knee pain of minimum 4 months and imaging findings of chondropathy or osteoarthritis (Kellgren-Lawrence score of ≤3) were allocated to PRP injections (n=96, mean age 53.3 y, 63.8% women) or HA injections (n=96, mean age 57.5 y, 58.4% women). The patients received 3 weekly intraarticular injections of PRP or high-molecular-weight HA. There was no additional rehabilitation program following injections except the instructions for a short rest and cold therapy. Main outcome measure was the International Knee Documentation Committee (IKDC) subjective score. Secondary outcome measures were the Knee injury and Osteoarthritis Outcome Score, EuroQol visual analog scale, and Tegner score. Two patients from PRP group and seven patients from HA group were excluded from statistical analysis due to lack of complete data at final evaluation. The study had 80% power to detect a clinically relevant 6.7 points difference between groups in IKDC subjective score at the 12-month follow-up. The PRP and HA groups both improved from baseline in all the clinical scores used, with no statistically significant differences between groups. The authors concluded that the injections of PRP did not improve pain and knee function more than HA in patients with knee cartilage degeneration and osteoarthritis.