title: Effect of pentoxifylline on histopathological changes in steroid-induced osteonecrosis of femoral head: experimental study in chicken.
abstract: OBJECTIVE
  Pentoxifylline (PTX) is a derivative of methylxanthine and is used in peripheral vascular and cerebrovascular diseases for its effect on the regulation of blood circulation. We investigated whether PTX could be beneficial for femoral head osteonecrosis associated with steroid through these effects.
  
  
  METHODS
  Sixty mature Leghorn type chickens were chosen and divided into three groups. The 25 chickens in group A were given a weekly dose of 3 mg/kg/week methylprednisolone acetate intramuscularly. Four chickens in group B died after the first drug injection and were excluded from the study. Therefore, the remaining 21 chickens in group B were additionally given 25 mg/kg/day pentoxifylline intramuscularly, along with the steroid medication as given in group A. The ten chickens in group C were not given any injections, as they were accepted as the control group. After the sacrifice of the animals at week 14, both femoral heads were taken from each animal. The animals which died along the course of the study also underwent pathological examination but were not a part of the statistical analysis.
  
  
  RESULTS
  In this study, steroid induced femoral head osteonecrosis has been experimentally observed in chickens after high doses of corticosteroid therapy. The chickens were given pentoxifylline in order to prevent the effects of steroid on bones and bone marrow. The results showed that chickens are suitable osteonecrosis models, and that steroid causes adipogenesis and necrosis in the bone marrow and the death of the subchondral bone.
  
  
  CONCLUSIONS
  The results of this study hint at the assumption that PTX may have a positive benefit on ONFH. PTX seems to minimise the effects of the steroid and reduce the incidence of ONFH.
authors.affiliation: Orthopaedics and Traumatology, Anadolu Medical Center, Kocaeli, Turkey. yenererken@yahoo.com
authors.forename: H Yener
authors.initials: HY
authors.lastname: Erken
authors.forename: Onder
authors.initials: O
authors.lastname: Ofluoglu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Aktas
authors.forename: Cumhur
authors.initials: C
authors.lastname: Topal
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Yildiz
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects / Q000473:pathology; D002645:Chickens; D004195:Disease Models, Animal; D005270:Femur Head / Q000187:drug effects / Q000473:pathology; D005271:Femur Head Necrosis / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D005938:Glucocorticoids / Q000633:toxicity; D007273:Injections, Intramuscular; D008297:Male; D008775:Methylprednisolone / Q000633:toxicity; D009336:Necrosis / Q000139:chemically induced / Q000473:pathology; D010431:Pentoxifylline / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D005938:Glucocorticoids; D014665:Vasodilator Agents; D010431:Pentoxifylline; D008775:Methylprednisolone