title: Provocative discography screening improves surgical outcome.
abstract: OBJECTIVE
  The objective of this study was to compare the surgical outcomes of patients operated on, with or without discography prior to operation.
  
  
  METHODS
  The study was designed as a randomized controlled trial, using power analysis with McNemar's test on two correlated proportions. The study comprised of 310 patients divided into trial (207) and control (103) groups. Inclusion criteria were low back pain resistant to nonsurgical treatment for more than 6 months and conventional radiological findings showing degenerative changes without a clear generator of pain. Exclusion criteria were red flags (tumor, trauma, and infection). After standard radiological diagnostic imaging (X-ray, CT, and MR), patients filled in the Oswestry Disability Index (ODI), SF-36, Zung, and MSP questionnaires. Depending on their radiological findings, patients were included and randomly placed in the trial or control group. At the 1-year follow-up examination, patients filled in the ODI, SF-36, and Likert scale questionnaires.
  
  
  RESULTS
  The difference between preoperative and postoperative ODI in the control group degenerative disc disease (DDD) subgroup was 22.07 %. The difference between preoperative and postoperative ODI in the trial group DDD subgroup was 35.04 %. Differences between preoperative and postoperative ODI in the control group other indications subgroup was 26.13 %. Differences between preoperative and postoperative ODI in the trial group other indications subgroup was 28.42 %.
  
  
  CONCLUSIONS
  DDD treated surgically without discography did not reach the clinically significant improvement of 15 ODI points for the patients treated with fusion. Provocative discography screening with psychological testing in the trial group made improvement following fusion clinically significant.
authors.affiliation: Department of Radiology, Clinic for Traumatology, University Hospital Sisters of Mercy, Draskoviceva 19, 10000, Zagreb, Croatia, hpetra23@gmail.com.
authors.forename: Petra
authors.initials: P
authors.lastname: Margetic
authors.forename: Roman
authors.initials: R
authors.lastname: Pavic
authors.forename: Marin F
authors.initials: MF
authors.lastname: Stancic
mesh_terms: D015984:Causality; D015897:Comorbidity; D017523:Croatia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery*; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011859:Radiography; D012307:Risk Factors; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome