title: The effect of platelet-rich plasma gel in the early phase of patellar tendon healing.
abstract: BACKGROUND
  The aim of this study is to assess if an application of platelet-rich plasma (PRP) gel would improve the mechanical properties of rabbit's patellar tendon after resecting its central portion.
  
  
  METHODS
  Forty skeletally mature New Zealand White rabbits were used. Two groups ten rabbits each (PRP and control group) were used to evaluate mechanical properties and histology after 14 days and two groups ten rabbits each (PRP and control groups) were used to evaluate mechanical properties and histology after 28 days.
  
  
  RESULTS
  At 14 days, PRP group showed a 72.2% increase in force at failure, a 39.1% increase in ultimate stress, and a 53.1% increase in stiffness, as compared with controls. These changes were statistically significant (P < 0.05). At 28 days, there was no longer any significant difference between PRP and control groups (P > 0.05).
  
  
  CONCLUSIONS
  In our study, the mechanical properties of the regenerated tendon in the PRP group were significantly improved in relation to the control group. It appears that PRP has a strong effect in the early phase of tendon healing. This effect is probably due to the growth factors that are released from the platelets during activation.
authors.affiliation: Democritus University of Thrace, Argyrokastrou 31B, Vrilissia, Athens, Greece. dimitrislyras@yahoo.gr
authors.forename: Dimitris N
authors.initials: DN
authors.lastname: Lyras
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kazakos
authors.forename: Dionysios
authors.initials: D
authors.lastname: Verettas
authors.forename: Sotirios
authors.initials: S
authors.lastname: Botaitis
authors.forename: George
authors.initials: G
authors.lastname: Agrogiannis
authors.forename: Anna
authors.initials: A
authors.lastname: Kokka
authors.forename: Michail
authors.initials: M
authors.lastname: Pitiakoudis
authors.forename: Athanasios
authors.initials: A
authors.lastname: Kotzakaris
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D017847:Patellar Ligament / Q000187:drug effects* / Q000293:injuries / Q000502:physiology; D010976:Platelet Count; D053657:Platelet-Rich Plasma; D011817:Rabbits; D018709:Statistics, Nonparametric; D013708:Tendon Injuries / Q000503:physiopathology*; D016212:Transforming Growth Factor beta / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A