title: The relation between serum levels of osteoprotegerin and postoperative epidural fibrosis in patients who underwent surgery for lumbar disc herniation.
abstract: OBJECTIVE
  Epidural fibrosis (EF) is a part of the normal physiological tissue response to laminectomy and it is an important cause of failed back surgery syndrome (FBSS). Osteoprotegerin (OPG) is a soluble member of the tumor necrosis factor receptor family, and is expressed in high concentrations by a variety of tissues and cell types. The objective of this study was to evaluate the relationship between serum OPG levels, and the existence of postoperative EF in patients with lumbar disc herniation. It has been suggested that cytokines and growth factors, which play a role in the wound healing, may enhance the expression of OPG.
  
  
  METHODS
  Forty women who underwent surgery for lumbar disc herniation were included in this study. Postoperative MRI was performed to assess EF in all patients.
  
  
  RESULTS
  The serum OPG levels of subjects with postoperative EF were significantly higher than those of subjects without postoperative EF (4.72 +/- 0.27 versus 3.25 +/-0.41 pmol/l; p=0.005)
  
  
  CONCLUSIONS
  Although the role of OPG in the development of EF is poorly understood, our results suggest that elevated levels of serum OPG are associated with and may play a role in the pathogenesis of fibrotic process.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Baskent University, Adana, Turkey. oraysen@yahoo.com
authors.forename: Orhan
authors.initials: O
authors.lastname: Sen
authors.forename: Adnan
authors.initials: A
authors.lastname: Gokcel
authors.forename: Osman
authors.initials: O
authors.lastname: Kizilkilic
authors.forename: Bulent
authors.initials: B
authors.lastname: Erdogan
authors.forename: M Volkan
authors.initials: MV
authors.lastname: Aydin
authors.forename: Nurzen
authors.initials: N
authors.lastname: Sezgin
authors.forename: Ozlem
authors.initials: O
authors.lastname: Yalcin
authors.forename: Hakan
authors.initials: H
authors.lastname: Caner
authors.forename: Nur
authors.initials: N
authors.lastname: Altinors
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D015519:Bone Density; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004824:Epidural Space / Q000378:metabolism*; D005260:Female; D005355:Fibrosis / Q000097:blood* / Q000209:etiology; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000150:complications* / Q000601:surgery; D008161:Lumbosacral Region / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D053244:Osteoprotegerin; D011184:Postoperative Period; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood*; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D006023:Glycoproteins; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506030:TNFRSF11B protein, human