title: Incidental dural tear in spine surgery: analysis of a nationwide database.
abstract: OBJECTIVE
  The purpose of this study was to report the incidence of dural tear (DT) in spine surgery, risk factors, and patient outcomes on a national level.
  
  
  METHODS
  Clinical data were obtained from the Nationwide Inpatient Sample for 2009. Patients who underwent spine surgery were identified and, among them, patients who had DT were identified, according to the International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) codes. Patient and hospital demographic data were retrieved. The incidence of DT and in-hospital patient outcomes were analyzed. Multivariate logistic regression analysis was performed to identify the risk factors for DT.
  
  
  RESULTS
  The incidence of DT was 2.7 % (17,932/665,818). Multivariate analysis revealed that older age, female gender, increased Elixhauser comorbidity score, and high hospital caseload were the significant risk factors for DT. Comparison between patients with and without DT showed that those with DT had significantly higher overall in-hospital complications (18.8 vs. 10.2 %), higher in-hospital mortality rate (0.4 vs. 0.3 %), longer hospital stays (5.1 vs. 3.7 days), lower proportion discharged home routinely (61.0 vs. 76.8 %), and increased total hospital charges ($85,138 vs. $71,808), respectively.
  
  
  CONCLUSIONS
  The reported incidence of DT in spine surgery was 2.7 % in the US. Risk factors included older age, female gender, increased comorbidities, and high hospital caseload. DT increased the rate of in-hospital complications and mortality and health care burdens.
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 East 17th St., New York, NY, 10003, USA, hiroyoshihara55@yahoo.co.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshihara
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yoneoka
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004388:Dura Mater / Q000293:injuries*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007431:Intraoperative Complications / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013131:Spine / Q000601:surgery*; D014481:United States / Q000453:epidemiology; D055815:Young Adult