title: Effect of hylan G-F 20 in Achilles' tendonitis: an experimental study in rats.
abstract: OBJECTIVE
  To investigate the local effects of hylan G-F 20 on locally administered corticosteroid-induced experimental Achilles' tendonitis.
  
  
  METHODS
  Before-after trial.
  
  
  METHODS
  Institutional practice.
  
  
  METHODS
  Convenience sample of 18 male Wistar white rats (weight range, 322-375 g).
  
  
  METHODS
  After performing Achilles' degeneration with local corticosteroid injections, the rats were divided into 4 groups. The right Achilles' tendon of the rats served as the hylan injection group and the left tendon as the control group, which was injected with saline at 5-day intervals. The tendons and paratenons were excised at the end of 60 or 75 days and evaluated histopathologically and statistically.
  
  
  METHODS
  Histopathologic changes, including staining affinity, nuclear appearance, fibrillar appearance for tendon and thickness, occurrence of fibrosis and edema, capillary changes, and inflammation for paratenon, were assessed according to a semiquantitative scoring system. The Mann-Whitney U test was used for statistical analysis, with a P value of.05 or less considered statistically significant.
  
  
  RESULTS
  Semiquantitative scoring of histopathologic changes showed that histologic appearances differed between the hylan and saline groups and between 2 hylan groups. Hylan-injected tendons and paratenons demonstrated significantly lower scores, especially after 75 days.
  
  
  CONCLUSIONS
  Hylan G-F 20 has a promising curative effect on the tendon and paratenon and can be used in Achilles' tendonitis. This finding should be supported by biomechanical and biochemical studies.
authors.affiliation: Department of Orthopaedics and Traumatology, Dokuz Eylül University, School of Medicine, Izmir, Turkey. hasan.tatari@deu.edu.tr
authors.forename: Hasan
authors.initials: H
authors.lastname: Tatari
authors.forename: Eyad
authors.initials: E
authors.lastname: Skiak
authors.forename: Hakan
authors.initials: H
authors.lastname: Destan
authors.forename: Cağnur
authors.initials: C
authors.lastname: Ulukuş
authors.forename: Erdener
authors.initials: E
authors.lastname: Ozer
authors.forename: Safa
authors.initials: S
authors.lastname: Satoğlu
mesh_terms: D000125:Achilles Tendon / Q000473:pathology; D000818:Animals; D001623:Betamethasone / Q000031:analogs & derivatives*; D002908:Chronic Disease; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004353:Drug Evaluation, Preclinical; D004487:Edema / Q000209:etiology; D005355:Fibrosis; D006820:Hyaluronic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D007267:Injections; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index; D016037:Single-Blind Method; D012965:Sodium Chloride / Q000627:therapeutic use; D018709:Statistics, Nonparametric; D052256:Tendinopathy / Q000139:chemically induced / Q000150:complications / Q000188:drug therapy* / Q000473:pathology
chemical_list: D004338:Drug Combinations; C032812:betamethasone dipropionate, betamethasone sodium phosphate drug combination; C049816:hylan; D012965:Sodium Chloride; D006820:Hyaluronic Acid; D001623:Betamethasone