title: Prevalence of Diffuse Idiopathic Skeletal Hyperostosis in Patients with Spinal Disorders.
abstract: METHODS
  Retrospective cohort study.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in patients with spinal diseases determined by roentgen images of the whole spine.
  
  
  BACKGROUND
  Although several studies have investigated the prevalence of DISH in healthy subjects, no detailed data have been reported on the prevalence of DISH in patients with degenerative spinal disorders.
  
  
  METHODS
  Standing whole-spine roentgen images of 345 consecutive patients who underwent surgery in our hospital were obtained. Patients aged <18 years or with congenital spinal disease, metastatic spinal tumors, or inflammatory spinal disease were excluded. In total, 281 patients were eligible for inclusion. The presence of DISH was assessed according to Resnick's criteria and Mata's scoring system. The prevalence, location, and numbers of fused vertebral bodies of DISH were recorded.
  
  
  RESULTS
  DISH was present in 25.6% of patients (72/281). The prevalence of DISH in the 41-49, 50-59, 60-69, 70-79, and ≥80 year age groups was 8.3% (2/24), 9.8% (5/51), 16.0% (12/75), 49.5% (48/97), and 33.3% (4/12), respectively; the prevalence increased with age. The average number of fused vertebral bodies was 7.5. More than 80% of DISH was located from T7 to T11, and more than 95% of DISH was located at T9/10. Patients with DISH were significantly older (71.1 years vs. 60.9 years,p<0.05), and men were more likely to have DISH than women (p<0.05).
  
  
  CONCLUSIONS
  In patients with degenerative spinal diseases with DISH, fused vertebrae were found most frequently in the lower thoracic spine, and their prevalence increased with age. DISH may be an age-related skeletal disorder with a higher overall prevalence in patients with spinal disorders than that in healthy subjects.
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiromitsu
authors.identifier: 0000-0002-3126-0046
authors.initials: H
authors.lastname: Toyoda
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hidetomi
authors.initials: H
authors.lastname: Terai
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kentaro
authors.identifier: 0000-0001-5454-4554
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department Orthopaedic Surgery, Yodogawa Christian Hospital, Osaka, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Dohzono
authors.affiliation: Department of Orthopaedic Surgery, Osaka Rosai Hospital, Osaka, Japan.
authors.forename: Tomiya
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroaki
authors.identifier: 0000-0002-0593-8810
authors.initials: H
authors.lastname: Nakamura
keywords: Ankylosing hyperostoses; Diffuse idiopathic skeletal hyperostosis; Forestier's disease; Spinal diseases