Published online Sep 18, 2019. doi: 10.5312/wjo.v10.i9.310
Peer-review started: March 8, 2019
First decision: April 16, 2019
Revised: May 10, 2019
Accepted: August 12, 2019
Article in press: August 13, 2019
Published online: September 18, 2019
Knee osteoarthritis is the most common articular disease that manifests as functional pain and joint stiffness, leading to disability in the elderly. More than 10% of the people aged ≥ 60 years suffer from this disease.
Hyaluronic acid is a therapeutic option for knee osteoarthritis. However, it has short-term effects on control of symptoms. Platelet-rich plasma (PRP) is also suggested for treatment of knee osteoarthritis. However, evidence about the clinical use of PRP is still insufficient. Investigations comparing the efficacy of these two drugs together are also insufficient.
The objective of this study was to compare the therapeutic efficacy of intra-articular injection of two different doses of PRP versus hyaluronic acid in three groups of patients with knee osteoarthritis.
This single-blinded randomized controlled trial study involved 95 patients with bilateral knee osteoarthritis. Thirty-one subjects received a single injection of PRP (group PRP-1), 33 subjects received two injections of PRP at an interval of 3 wk (group PRP-2) and 31 subjects received three injections of hyaluronic acid at 1-wk intervals (group hyaluronic acid). The patients were investigated prospectively at the enrollment and at 4-, 8- and 12-wk follow-up with the Western Ontario and McMaster Universities Arthritis Index and Visual Analogue Scale questionnaires.
In the groups PRP-1, PRP-2 and hyaluronic acid, 86%, 100% and 0% of the patients, respectively experienced at least a 30% decrease in the total score for the Western Ontario and McMaster Universities Arthritis Index pain subscale from baseline to wk 12 of the intervention (P < 0.001). The mean total Western Ontario and McMaster Universities Arthritis Index scores for groups PRP-1, PRP-2 and hyaluronic acid at baseline were 63.71, 61.57 and 63.11, respectively, which were significantly improved at final follow-up to 42.5, 35.32 and 57.26, respectively. The highest efficacy of PRP was observed in both groups at wk 4 with about a 50% decrease in the symptoms compared with about a 25% decrease for the hyaluronic acid group. Group PRP-2 had higher efficacy than group PRP-1. No major adverse effects were found during the study.
PRP is a safe and efficient therapeutic option for treatment of knee osteoarthritis (significantly better than hyaluronic acid). The efficacy of PRP increases after multiple injections.
Future studies with longer follow-up are suggested to evaluate long-term efficacy and potential compactions. We also propose that future studies use magnetic resonance imaging to assess and quantify cartilage regeneration if costs and ethical issues allow.