title: Alterations of sympathetic nerve fibers in avascular necrosis of femoral head.
abstract: OBJECTIVE
  Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH.
  
  
  METHODS
  Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope.
  
  
  RESULTS
  Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages.
  
  
  CONCLUSIONS
  ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.
authors.affiliation: Department of Orthopedics, Qilu Hospital of Shandong University China.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Qilu Hospital of Shandong University China.
authors.forename: Peilai
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, Qilu Hospital of Shandong University China.
authors.forename: Yuankai
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, Qilu Hospital of Shandong University China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000320:Adrenergic Fibers / Q000473:pathology*; D000818:Animals; D004195:Disease Models, Animal; D005269:Femur / Q000294:innervation*; D005271:Femur Head Necrosis / Q000473:pathology*; D007150:Immunohistochemistry; D011817:Rabbits
keywords: Avascular necrosis of the femoral head; sympathetic nerve fibers