title: Predictors of Outcome in Conservative and Minimally Invasive Surgical Management of Pain Originating From the Sacroiliac Joint: A Pooled Analysis.
abstract: METHODS
  A pooled patient-level analysis of two multicenter randomized controlled trials and one multicenter single-arm prospective trial.
  
  
  OBJECTIVE
  The aim of this study was to identify predictors of outcome of conservative and minimally invasive surgical management of pain originating from the sacroiliac joint (SIJ).
  
  
  BACKGROUND
  Three recently published prospective trials have shown that minimally invasive SIJ fusion (SIJF) using triangular titanium implants produces better outcomes than conservative management for patients with pain originating from the SIJ. Due to limitations in individual trial sample size, analyses of predictors of treatment outcome were not conducted.
  
  
  METHODS
  We pooled individual patient data from the three trials and used random effects models with multivariate regression analysis to identify predictors for treatment outcome separately for conservative and minimally invasive surgical treatment. Outcome was measured using visual analogue scale (VAS), Oswestry Disability Index (ODI), and EuroQOL-5D (EQ-5D).
  
  
  RESULTS
  We included 423 patients assigned to either nonsurgical management (NSM, n = 97) or SIJF (n = 326) between 2013 and 2015. The reduction in SIJ pain was 37.9 points larger [95% confidence interval (95% CI) 32.5-43.4, P < 0.0001] in the SIJF group than in the NSM group. Similarly, the improvement in ODI was 18.3 points larger (95% CI 14.3-22.4), P < 0.0001). In NSM, we found no predictors of outcome. In SIJF, a reduced improvement in outcome was predicted by smoking (P = 0.030), opioid use (P = 0.017), lower patient age (P = 0.008), and lower duration of SIJ pain (P = 0.028).
  
  
  CONCLUSIONS
  Our results support the view that SIJF leads to better treatment outcome than conservative management of SIJ pain and that a higher margin of improvement can be predicted in nonsmokers, nonopioid users, and patients of increased age and with longer pain duration.
  
  
  METHODS
  1.
authors.affiliation: Department of Neurosurgery, Charité, Berlin, Germany.
authors.forename: Julius
authors.initials: J
authors.lastname: Dengler
authors.affiliation: Department of Neurosurgery, University of Colorado, Aurora, CO.
authors.forename: Bradley
authors.initials: B
authors.lastname: Duhon
authors.affiliation: Department of Orthopedics, Yale University, New Haven, CT.
authors.forename: Peter
authors.initials: P
authors.lastname: Whang
authors.affiliation: Integrated Spine Care, Wawautosa, WI.
authors.forename: Clay
authors.initials: C
authors.lastname: Frank
authors.affiliation: Department of Orthopedic Surgery, Medical University of South Carolina, Charleston, SC.
authors.forename: John
authors.initials: J
authors.lastname: Glaser
authors.affiliation: Department of Orthopedics, Aleris, Ängelholm Hospital, Ängelholm, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Sturesson
authors.affiliation: Department of Orthopedics, University of California San Diego, San Diego, CA.
authors.forename: Steven
authors.initials: S
authors.lastname: Garfin
authors.affiliation: Clinical Affairs, SI-BONE, San Jose, CA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cher
authors.affiliation: School of Statistics, University of Minnesota, Minneapolis, MN.
authors.forename: Aaron
authors.initials: A
authors.lastname: Rendahl
authors.affiliation: Departments of Orthopedics and Neurosurgery, University of Minnesota, Minneapolis, MN.
authors.forename: David
authors.initials: D
authors.lastname: Polly
mesh_terms: D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000628:therapy; D001416:Back Pain / Q000175:diagnosis / Q000601:surgery*; D000072700:Conservative Treatment / Q000379:methods / Q000639:trends*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods / Q000639:trends*; D059408:Pain Management / Q000379:methods / Q000639:trends*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012446:Sacroiliac Joint / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome