title: Loss of sympathetic nerve fibers in vital intertrochanteric bone cylinders lateral to osteonecrosis of the femoral head.
abstract: OBJECTIVE
  Although etiology in osteonecrosis of the femoral head mainly depends on alterations of bone blood flow, vasoregulatory nerve fibers of the sympathetic and sensory nervous system have never been investigated in bone of osteonecrosis patients. This study aimed to demonstrate density of sympathetic and sensory nerve fibers in femoral head and, for comparison, adjacent periosteum, and synovium of the hip joint in patients with osteonecrosis.
  
  
  METHODS
  Immunofluorescence staining techniques were applied using specific nerve fiber markers. A total of 10 patients with early femoral head osteonecrosis (ARCO I-II), 10 with late femoral head osteonecrosis (ARCO III-IV), and 10 patients with osteoarthritis of the hip were investigated.
  
  
  RESULTS
  In the bone of the femoral head, density of sympathetic nerve fibers was lower in early and late osteonecrosis compared to osteoarthritis. There was a marked preponderance of sympathetic over sensory nerve fibers in bone of osteoarthritis patients, which was opposite in early and late femoral head osteonecrosis. In periosteum, density of sympathetic nerve fibers was similar in all three groups but density of sensory nerve fibers and cellularity were higher in early osteonecrosis compared to the other two groups.
  
  
  CONCLUSIONS
  Due to the different affinity of norepinephrine for α-adrenoceptors (high affinity) and β-adrenoceptors (low affinity), the loss of sympathetic nerve fibers relative to sensory nerve fibers in femoral head osteonecrosis might change the femoral head blood flow (towards α-adrenergic vasoconstriction). Higher density of sensory nerve fibers and cellularity in periosteum might indicate an inflammatory response in early osteonecrosis.
authors.affiliation: Department of Orthopedic Surgery, University Hospital Regensburg, Asklepios Clinic Bad Abbach, Regensbur, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Beckmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Knödl
authors.forename: Eva
authors.initials: E
authors.lastname: Bauser
authors.forename: Markus
authors.initials: M
authors.lastname: Tingart
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.forename: Rainer H
authors.initials: RH
authors.lastname: Straub
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D005270:Femur Head / Q000294:innervation* / Q000473:pathology*; D005271:Femur Head Necrosis / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D006621:Hip Joint / Q000294:innervation / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000378:metabolism / Q000473:pathology*; D015207:Osteoarthritis, Hip / Q000473:pathology; D010521:Periosteum / Q000294:innervation / Q000473:pathology; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000473:pathology; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000473:pathology*; D013583:Synovial Membrane / Q000294:innervation / Q000473:pathology
chemical_list: D015415:Biomarkers