title: Ankylosing spondylitis does not increase the risk of neurogenic heterotopic ossification in patients with a spinal cord injury: a retrospective cohort study.
abstract: METHODS
  Retrospective chart review.
  
  
  OBJECTIVE
  The present study was performed to analyze the impact of ankylosing spondylitis (AS) in developing heterotopic ossification (HO) in patients following spinal cord injury.
  
  
  METHODS
  Department of Spinal Cord Injury and Department of General and Trauma Surgery, BG-University Hospital Bergmannsheil Bochum, Ruhr-University Bochum, Germany.
  
  
  METHODS
  Between January 2003 and December 2015, 67 patients with AS and SCI were included in the study. The control group consisted of 141 patients with SCI and without AS. The definitive diagnosis of HO was made via magnetic resonance imaging or computed tomography. Primary outcome measure was to analyze the impact of AS on the development of HO.
  
  
  RESULTS
  Fifteen out of 67 AS patients (22.4%) had a diagnosed HO. In the control group, 28 of 141 patients (19.9%) suffered from HO. Patients with AS had no significant higher risk for HO development compared with patients without AS (RR=1.16; 95% CI=0.65-2.09). However, patients with a complete neurological deficit had a twofold higher risk for HO development (RR=2.55; 95% CI=1.26-5.16).
  
  
  CONCLUSIONS
  AS does not increase the risk for HO development in patients with spinal cord injury.
authors.affiliation: Department of General and Trauma Surgery, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ohlmeier
authors.affiliation: Department of General and Trauma Surgery, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Karras
authors.affiliation: Department of General and Trauma Surgery, Medical School Hannover, Hannover, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Suero
authors.affiliation: Department of Spinal Cord Injury, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Grasmücke
authors.affiliation: Department of Spinal Cord Injury, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Aach
authors.affiliation: Department of Spinal Cord Injury, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Meindl
authors.affiliation: Department of General and Trauma Surgery, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: T A
authors.initials: TA
authors.lastname: Schildhauer
authors.affiliation: Department of Spinal Cord Injury, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Citak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000175:diagnosis* / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013119:Spinal Cord Injuries / Q000175:diagnosis* / Q000453:epidemiology*; D013167:Spondylitis, Ankylosing / Q000175:diagnosis* / Q000453:epidemiology*