title: The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Quite a few randomized controlled trials (RCTs) investigating the efficacy of platelet-rich plasma (PRP) for treatment of knee osteoarthritis (OA) have been recently published. Therefore, an updated systematic review was performed to evaluate the temporal effect of PRP on knee pain and physical function.
  
  
  METHODS
  Pubmed, Embase, Cochrane library, and Scopus were searched for human RCTs comparing the efficacy and/or safety of PRP infiltration with other intra-articular injections. A descriptive summary and quality assessment were performed for all the studies finally included for analysis. For studies reporting outcomes concerning Western Ontario and McMaster Universities Arthritis Index (WOMAC) or adverse events, a random-effects model was used for data synthesis.
  
  
  RESULTS
  Fourteen RCTs comprising 1423 participants were included. The control included saline placebo, HA, ozone, and corticosteroids. The follow-up ranged from 12 weeks to 12 months. Risk of bias assessment showed that 4 studies were considered as moderate risk of bias and 10 as high risk of bias. Compared with control, PRP injections significantly reduced WOMAC pain subscores at 3, 6, and 12 months follow-up (p = 0.02, 0.004, <0.001, respectively); PRP significantly improved WOMAC physical function subscores at 3, 6, and 12 months (p = 0.002, 0.01, <0.001, respectively); PRP also significantly improved total WOMAC scores at 3, 6 and 12 months (all p < 0.001); nonetheless, PRP did not significantly increased the risk of post-injection adverse events (RR, 1.40 [95% CI, 0.80 to 2.45], I2= 59%, p = 0.24).
  
  
  CONCLUSIONS
  Intra-articular PRP injections probably are more efficacious in the treatment of knee OA in terms of pain relief and self-reported function improvement at 3, 6 and 12 months follow-up, compared with other injections, including saline placebo, HA, ozone, and corticosteroids.
  
  
  BACKGROUND
  PROSPERO CRD42016045410 . Registered 8 August 2016.
authors.affiliation: Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
authors.forename: Longxiang
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Yuan
authors.affiliation: Section of Clinical Epidemiology, Institute of Orthopaedic Traumatology affiliated to Shanghai Jiaotong University, 600 Yishan Road, Shanghai, 200233, China.
authors.forename: Shengbao
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China. xuetaoxie@163.com.
authors.forename: Xuetao
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
authors.forename: Changqing
authors.initials: C
authors.lastname: Zhang
mesh_terms: D006801:Humans; D006820:Hyaluronic Acid / Q000009:adverse effects / Q000627:therapeutic use; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement / Q000379:methods; D053657:Platelet-Rich Plasma; D011859:Radiography; D016032:Randomized Controlled Trials as Topic; D020127:Recovery of Function; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D006820:Hyaluronic Acid
keywords: Hyaluronic acid; Knee; Osteoarthritis; Platelet-rich plasma; Systematic review