title: The postoperative lumbar spine: evaluation of epidural scar over a 1-year period.
abstract: OBJECTIVE
  We documented the morphological changes on enhanced MR imaging studies that occur in epidural scar over a period of 1 year after lumbar diskectomy.
  
  
  METHODS
  The study population was culled from a randomized, multicenter clinical trial designed to evaluate the efficacy of a device inhibiting postoperative epidural fibrosis after single-level, unilateral laminectomy/diskectomy for herniated lumbar disk. Analysis was restricted to 71 control subjects who did not receive the device. All patients underwent surgery after receiving clinical and MR examinations, with follow-up MR studies at 6 and 12 months. Evaluation of all MR images was performed by one interpreter, who was blinded to treatment arm and clinical findings. The extent of epidural scar seen at the 6- and 12-month MR examinations was graded on a scale of 0 to 4 for each quadrant at each imaging section encompassing the surgical level.
  
  
  RESULTS
  Eighty-five percent of the patients had no change in the amount of anterior epidural scar between the 6- and 12-month MR examinations; 75% of the patients showed no change in the amount of posterior epidural scar between the 6- and 12-month examinations.
  
  
  CONCLUSIONS
  The majority of our patients had no change in the amount of epidural scarring visible at enhanced MR imaging over a 1-year period after lumbar laminectomy/diskectomy.
authors.affiliation: Division of Radiology, Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Ross
authors.forename: N
authors.initials: N
authors.lastname: Obuchowski
authors.forename: R
authors.initials: R
authors.lastname: Zepp
mesh_terms: D002921:Cicatrix / Q000473:pathology* / Q000601:surgery; D017586:Diskectomy; D004824:Epidural Space; D005355:Fibrosis / Q000517:prevention & control; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D007796:Laminectomy; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D011183:Postoperative Complications / Q000517:prevention & control; D013997:Time Factors