title: The role of standing flexion-extension radiographs for spondylolisthesis following single level disk surgery.
abstract: OBJECTIVE
  Spondylolisthesis is the forward displacement of a lumbar vertebra relative to the adjacent vertebra, occurs as result degeneration or surgery and is a special type of lumbar instability. There is no consensus about which radiologic modality or findings truly reflect the lumbar instability and the exact incidence after single level disk surgery is unknown.
  
  
  METHODS
  In this prospective study, we have included 90 patients who were operated by the same surgeon with single level disk herniation. We aimed at evaluating the post-operative lumbar spondylolisthesis, with flexion and extension lateral radiographs in addition to standard magnetic resonance imaging (MRI).
  
  
  RESULTS
  We have seen spondylolisthesis in six of 90 cases with standing lateral flexion-extension radiographs, which were undefinable with MRI. Pain intensity and functional-economic rating scale (Prolo scale) were unremarkable.
  
  
  CONCLUSIONS
  We have concluded that standing flexion-extension radiographs should be routinely combined in patients with failed back surgery syndrome and even if lumbar instability is clinically suspected, especially when conventional MR examination is normal. When the MR examination showed spondylolisthesis, standing flexion-extension radiographs could not give additional information.
authors.affiliation: Department of Radiology, Baskent University Adana Teaching and Medical Research Center, Adana, Turkey. okizilkilic@baskent-adn.edu.tr
authors.forename: Osman
authors.initials: O
authors.lastname: Kizilkilic
authors.forename: Ozlem
authors.initials: O
authors.lastname: Yalcin
authors.forename: Orhan
authors.initials: O
authors.lastname: Sen
authors.forename: M Volkan
authors.initials: MV
authors.lastname: Aydin
authors.forename: Tulin
authors.initials: T
authors.lastname: Yildirim
authors.forename: Cem
authors.initials: C
authors.lastname: Hurcan
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D017586:Diskectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography / Q000379:methods; D013168:Spondylolisthesis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome