Comparison of epoprostenol and viscum album efficiencies in the treatment of avascular necrosis of the femoral head: An experimental animal study.

BACKGROUND:The aim of our study is to compare the efficacy of epoprostenol and viscum album in the treatment of femoral head avascular necrosis with an experimental study. Our hypothesis is that viscum album, which has similar properties to epoprostenol on the vascular system, is as effective as epoprostenol in the treatment of avascular necrosis. METHODS:Avascular necrosis was created on the femoral heads of 45 New Zealand type rabbits by surgical vascular deprivation method. The rabbits were divided into 3 groups. Group 1 was designed as a control group, in group 2 Ilomedin (epoprostenol analogue) was administrated to subjects and in group 3, Helixor (viscum album extract) was administrated. At the end of the study, there were nine subjects in each group. Osteocyte necrosis, bone marrow necrosis, new bone formation and cartilage degeneration were evaluated microscopically. The extent of bone necrosis and repair and involvement of epiphysis, the bone marrow cellularity ratio and trabecular bone volume were investigated. RESULTS:Subchondral necrosis was seen in more animals in the control group (p=0.03). Osteoblastic and osteoclastic activity were more prominent in the Ilomedin group (p=0.25 and 0.07, respectively). It was seen that the cartilages of the subjects in the Helixor and Ilomedin groups were less damaged. In the Ilomedin group, more animals were seen in the chronic phase of the repair process than in the other groups (p=0.07). Bone marrow cellularity was higher in treatment groups (22% and 20,6% for Ilomedin and Helixor, respectively, p=0,04). Trabecular volume was found to be increased in damaged femoral heads in the treatment groups, the highest increased observed in the Helixor group (p=0.01). CONCLUSION:Viscum album seems to be effective in decreasing the extention of necrosis and protecting the articular cartilage, and epoprostenol in increasing repair and regeneration.