Summary

Intraosseous injections of platelet rich plasma improve pain, function and quality of life as compared to intraarticular injections, and constitute a safe alternative for the treatment of advance knee osteoarthritis

Abstract

INTRODUCTION. The increasing prevalence of knee osteoarthritis (KOA), as well as the lack of effective treatments in moderate-severe stages, have made it the target of new biological therapies such as platelet rich plasma (PRP) and mesenchymal stem cell (MSC) research. Studies emphasise the importance of addressing the osteochondral functional unit (OFU) as a whole, as biochemical synergy and communication between the tissues is key in the pathogenesis of OA. The anti-inflammatory and immuno-modulatory effects of PRP make it a useful alternative to classic symptomatic treatments, yet intra-articular (IA) PRP injections alone appear ineffective in the later stages of KOA, as they do not target the subchondral bone.
OBJECTIVE. The purpose of this study is to assess the effectiveness of intraosseous (IO) PRP injections in patients with KOA as compared to IA at 0, 3 and 6 months.
Materials and methods. A controlled, double-blind, randomised clinical trial including patients with over 6 months of symptomatic KOA, Kellgren-Lawrence stages III and IV, who did not respond to NSAIDs, corticoid injections and viscosupplementation. Subjects received three IA PRP injections 1-2 weeks apart. Alongside the first infiltration, our study group was injected with IO PRP according to the PRGF-Endoret® technique while our control group was given the placebo (sodium chloride solution 0.9%). Joint pain and function were assessed via the Western Ontario and McMaster Universities Scores (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) scales at 0, 3 and 6 months after procedure.
RESULTS. 84 patients were included in the study with an average age of 59.77 ± 7.54 years. 46.4% were female. 40.6% were diagnosed with bilateral KOA, 23.2% left and 36.2% right side KOA. No statistically significant differences in patient characteristics were found between the two groups. Initial average WOMAC score for our study group was 55.03 ± 24.96 versus 53.38 ± 21.09 for our control group. Baseline mean overall KOOS score for either group was 109.11 ± 45.37 and 107.68 ± 39.19, respectively. Preliminary results show a significant improvement in pain reduction and quality of life (QoL) within both groups individually during follow-up. Patients who received IO PRP as opposed to placebo showed greater improvement on both WOMAC and KOOS scales, yet said difference was only found to be statistically significant (p 0.007) at the 6-month but not at the 3-month follow up (p 0.143).
DISCUSSION. Due to the growing prevalence of OA, it is crucial we learn more about the underlying physiopathology so we may prevent, stall or alter the course of this illness. Research has shown the importance of treating the OFU as a whole, thereby pushing biological therapies such as PRP technology to the forefront. PRP is an effective and safe alternative to classic symptomatic treatments for KOA. Our study shows that, while the benefits of IA PRP injections alone cannot be denied, their synergic action with IO PRP was key in improving pain, joint function and QoL. Administration of IO PRP should therefore be considered as a viable alternative when devising new treatment protocols for KOA.