A systematic review and meta-analysis for platelet-rich plasma in treatment of knee osteoarthritis

Objective:Knee osteoarthritis(KOA)is a common chronic joint disease that usually occurs in older people,and injuries articular cartilage and cartilage proliferation. Studies have shown that platelet-rich plasma(PRP),as one of non-surgical treatments,is used to alleviate the symptoms of patients with KOA,becoming popular with doctors. In this study,the purpose was to investigate the effects of platelet-rich plasma on the level of pain and function in patients with KOA. Methods:The Pubmed,Cochrane Library,Embase,and Medline were investigated from 2005 through May 2020. All randomized double-blind controlled trials on the effect of PRP injections for KOA were included. Outcome indicators included the Western Ontario and McMaster Universities Arthritis Index(WOMAC)and the Knee Osteoarthritis Outcome Score(KOOS)for function,the visual analogue scale(VAS)for pain,and adverse events(AEs). Review Manager 5.3 was used to calculate these outcome indicators. Results:In this study,(1)Seven studies met the eligibility criteria,including 250 patients in the experiment(PRP)group and 230 patients in the control(no PRP)group.(2)Meta-analysis results showed that the WOMAC scores were differed significantly between the PRP and no PRP groups at the 6 months follow-up(MD=9.63,95%CI:3.29 to 15.96,P=0.003),and 12 months follow-up(MD=3.85,95%CI:2.66 to 5.04,P<0.000 01)(P<0.05). In a comparison of KOOS function scores at the 6 months follow-up,PRP improved knee function scores more than no PRP(MD=8.63,95%CI:0.85 to 16.42,P=0.03)(P<0.05). PRP injections reduced pain more effectively than no PRP injections in patients with KOA at 3,6 months of follow-up,and the VAS pain score showed a significant difference(SMD=0.88,95%CI:0.13 to 1.62,P=0.02)(SMD=0.85,95%CI:0.11 to 1.59,P=0.002)(P<0.05). However,adverse events(AEs)were all not significantly different(RR=0.96,95%CI:0.65 to 1.40,P=0.82)(P>0.05).(3)Results showed that PRP has significant advantages in pain relief and functional improvement. Conclusion:In improving knee function and relieving pain,PRP showed superiority to other non-surgical treatments in long-term follow-up from well-designed double-blind trials. Due to the limited quality and data,more high-quality multi-center studies are required.