title: Comparative effectiveness of platelet-rich plasma injections for treating knee joint cartilage degenerative pathology: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To explore the effectiveness of platelet-rich plasma (PRP) in treating cartilage degenerative pathology in knee joints.
  
  
  METHODS
  Electronic databases, including PubMed and Scopus, were searched from the earliest record to September 2013.
  
  
  METHODS
  We included single-arm prospective studies, quasi-experimental studies, and randomized controlled trials that used PRP to treat knee chondral degenerative lesions. Eight single-arm studies, 3 quasi-experimental studies, and 5 randomized controlled trials were identified, comprising 1543 participants.
  
  
  METHODS
  We determined effect sizes for the selected studies by extracting changes in functional scales after the interventions and compared the PRP group pooled values with the pretreatment baseline and the groups receiving placebo or hyaluronic acid (HA) injections.
  
  
  RESULTS
  PRP injections in patients with knee degenerative pathology showed continual efficacy for 12 months compared with their pretreatment condition. The effectiveness of PRP was likely better and more prolonged than that of HA. Injection doses ≤2, the use of a single-spinning approach, and lack of additional activators led to an uncertainty in the treatment effects. Patients with lower degrees of cartilage degeneration achieved superior outcomes as opposed to those affected by advanced osteoarthritis.
  
  
  CONCLUSIONS
  PRP application improves function from basal evaluations in patients with knee joint cartilage degenerative pathology and tends to be more effective than HA administration. Discrepancy in the degenerative severity modifies the treatment responses, leading to participants with lower degrees of degeneration benefiting more from PRP injections.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, BeiHu Branch, and National Taiwan University College of Medicine, Taipei, Taiwan; Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ke-Vin
authors.initials: KV
authors.lastname: Chang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Hung
authors.affiliation: Department of Physical Medicine and Rehabilitation, Eka Hospital, Tangerang, Indonesia.
authors.forename: Fanny
authors.initials: F
authors.lastname: Aliwarga
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Tyng-Guey
authors.initials: TG
authors.lastname: Wang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, BeiHu Branch, and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Der-Sheng
authors.initials: DS
authors.lastname: Han
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: wenshiang@gmail.com.
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Chen
mesh_terms: D006801:Humans; D007270:Injections, Intra-Articular; D020370:Osteoarthritis, Knee / Q000628:therapy*; D017060:Patient Satisfaction; D053657:Platelet-Rich Plasma; D055675:Viscosupplements / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D055675:Viscosupplements
keywords: Cartilage; Knee; Osteoarthritis; Platelet-rich plasma; Rehabilitation