title: Predictive value of MRI in decision making for disc surgery for sciatica.
abstract: OBJECTIVE
  In a randomized controlled trial comparing surgery and prolonged conservative treatment for sciatica of 6-12 weeks' duration, more than one-third of patients assigned to conservative treatment underwent surgery. The objective of the present study was to evaluate whether MRI at baseline could have predicted this delayed surgery.
  
  
  METHODS
  Independently evaluated qualitative and quantitative MRI findings were compared between those patients who did and those who did not undergo surgery during follow-up in the conservative care group. In addition, area under the receiver operating characteristic (ROC) curve analysis was used to assess how well MRI parameters discriminated between those who did and those who did not undergo delayed surgery (0.5-0.7 poor discrimination, ≥ 0.7 acceptable discrimination).
  
  
  RESULTS
  Of 142 patients assigned to receive prolonged conservative care, 55 patients (39%) received delayed surgery. Of the 55 surgically treated patients, 71% had definite nerve root compression at baseline compared with 72% of conservatively treated patients (p = 0.76). Large disc herniations (size > 50% of spinal canal) were nearly equally distributed between those who did and those who did not undergo surgery (25% vs 21%, p = 0.65). The size of the dural sac was smaller in the patients who underwent surgery (101.2 vs 122.9 mm(2), p = 0.01). However, the size of the dural sac discriminated poorly between those who did and those who did not undergo delayed surgery (area under ROC curve, 0.62).
  
  
  CONCLUSIONS
  In patients who suffered from sciatica of 6-12 weeks' duration, MRI at baseline did not distinguish between patients who did and those who did not undergo delayed surgery.
authors.affiliation: Departments of Neurosurgery and 3Medical Decision Making, Leiden University Medical Center, Leiden;
authors.forename: Abdelilah
authors.initials: A
authors.lastname: el Barzouhi
authors.forename: Carmen L A M
authors.initials: CL
authors.lastname: Vleggeert-Lankamp
authors.forename: Geert J
authors.initials: GJ
authors.lastname: Lycklama à Nijeholt
authors.forename: Bas F
authors.initials: BF
authors.lastname: Van der Kallen
authors.forename: Wilbert B
authors.initials: WB
authors.lastname: van den Hout
authors.forename: Bart W
authors.initials: BW
authors.lastname: Koes
authors.forename: Wilco C
authors.initials: WC
authors.lastname: Peul
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000592:standards*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012585:Sciatica / Q000175:diagnosis / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome