title: Pain and activity levels before and after platelet-rich plasma injection treatment of patellar tendinopathy: a prospective cohort study and the influence of previous treatments.
abstract: OBJECTIVE
  The aim of this study was to evaluate the outcome of patients with patellar tendinopathy treated with platelet-rich plasma injections (PRP). Additionally, this study examined whether certain characteristics, such as activity level or previous treatment affected the results.
  
  
  METHODS
  Patients (n = 36) were asked to fill in the Victorian Institute of Sports Assessment - Patellar questionnaire (VISA-P) and visual analogue scales (VAS), assessing pain in activities of daily life (ADL), during work and sports, before and after treatment with PRP. Of these patients, 14 had been treated before with cortisone, ethoxysclerol, and/or surgical treatment (group 1), while the remaining patients had not been treated before (group 2).
  
  
  RESULTS
  Overall, group 1 and group 2 improved significantly on the VAS scales (p < .0.05). However, group 2 also improved on VISA-P (p = .0.003), while group 1 showed less healing potential (p = 0.060). Although the difference between group 1 and group 2 at follow-up was not considered clinically meaningful, over time both groups showed a clinically significant improvement.
  
  
  CONCLUSIONS
  After PRP treatment, patients with patellar tendinopathy showed a statistically significant improvement. In addition, these improvements can also be considered clinically meaningful. However, patients who were not treated before with ethoxysclerol, cortisone, and/or surgical treatment showed the improvement.
authors.affiliation: Department of Orthopaedics and Traumatology, St Elisabeth Hospital Tilburg, Tilburg, The Netherlands. t.gosens@elisabeth.nl
authors.forename: Taco
authors.initials: T
authors.lastname: Gosens
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Den Oudsten
authors.forename: Erik
authors.initials: E
authors.lastname: Fievez
authors.forename: Paula
authors.initials: P
authors.lastname: van 't Spijker
authors.forename: Alex
authors.initials: A
authors.lastname: Fievez
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001265:Athletic Injuries; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D007718:Knee Injuries / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D007719:Knee Joint / Q000473:pathology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000503:physiopathology; D059408:Pain Management; D010147:Pain Measurement; D017847:Patellar Ligament / Q000293:injuries* / Q000503:physiopathology; D053657:Platelet-Rich Plasma; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D052256:Tendinopathy / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D017211:Treatment Failure; D016896:Treatment Outcome