title: Platelet-rich plasma intra-articular knee injections for the treatment of degenerative cartilage lesions and osteoarthritis.
abstract: OBJECTIVE
  Platelet-rich plasma (PRP) therapy is a simple, low-cost and minimally invasive method that provides a natural concentrate of autologous blood growth factors (GFs) that can be used to enhance tissue regeneration. In a previous analysis of a 12-month follow-up study, promising results were obtained when treating patients affected by knee degeneration with PRP intra-articular injections. The main purpose of this study was to investigate the persistence of the beneficial effects observed.
  
  
  METHODS
  Of the 91 patients evaluated in the previous 12-month follow-up study, 90 were available for the 2-year follow-up (24 patients presented a bilateral lesion, in a total of 114 knees treated). All of the patients presented a chronic knee degenerative condition and were treated with three intra-articular PRP injections. IKDC and EQ-VAS scores were used for clinical evaluation. Complications, adverse events and patient satisfaction were also recorded.
  
  
  RESULTS
  All of the evaluated parameters worsened at the 24-month follow-up: these parameters were at significantly lower levels with respect to the 12-month evaluation (the IKDC objective evaluation fell from 67 to 59% of normal and nearly normal knees; the IKDC subjective score fell from 60 to 51), even if they remained higher than the basal level. Further analysis showed better results in younger patients (P = 0.0001) and lower degrees of cartilage degeneration (P < 0.0005). The median duration of the clinical improvement was 9 months.
  
  
  CONCLUSIONS
  These findings indicate that treatment with PRP injections can reduce pain and improve knee function and quality of life with short-term efficacy. Further studies are needed to confirm these results and understand the mechanism of action, and to find other application modalities, with different platelet and GF concentrations and injection timing, which provide better and more durable results.
authors.affiliation: Biomechanics Laboratory-III Clinic, Rizzoli Orthopaedic Institute, Via Di Barbiano 1/10, 40136, Bologna, Italy. g.filardo@biomec.ior.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Kon
authors.forename: Roberto
authors.initials: R
authors.lastname: Buda
authors.forename: Antonio
authors.initials: A
authors.lastname: Timoncini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Di Martino
authors.forename: Annarita
authors.initials: A
authors.lastname: Cenacchi
authors.forename: Pier Maria
authors.initials: PM
authors.lastname: Fornasari
authors.forename: Sandro
authors.initials: S
authors.lastname: Giannini
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002358:Cartilage, Articular / Q000503:physiopathology*; D015331:Cohort Studies; D003240:Connective Tissue Diseases / Q000175:diagnosis / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000628:therapy*; D053657:Platelet-Rich Plasma; D012038:Regeneration / Q000502:physiology; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult