title: The Association between the Cross-Sectional Area of the Dural Sac and Low Back Pain in a Large Population: The Wakayama Spine Study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relations between the degree of encroachment, measured as the cross-sectional area of the dural sac, and low back pain in a large population.
  
  
  METHODS
  In this cross-sectional study, data from 802 participants (247 men, 555 women; mean age, 63.5 years) were analyzed. The measurement of the cross-sectional area of the dural sac from the level of L1/2 to L4/5 was taken using axial T2-weighted images. The minimum cross-sectional area was defined as the cross-sectional area of the dural sac at the most constricted level in the examined spine. Participants were divided into three groups according to minimum cross-sectional area measurement quartiles (less than the first quartile, between the first and third quartiles, and greater than the third quartile). A multivariate logistic regression analysis was used to estimate the association between the minimum cross-sectional area and the prevalence of low back pain.
  
  
  RESULTS
  The mean minimum cross-sectional area was 117.3 mm2 (men: 114.4 mm2; women: 118.6 mm2). A logistic regression analysis adjusted for age, sex, body mass index, and other confounding factors, including disc degeneration, showed that a narrow minimum cross-sectional area (smaller than the first quartile) was significantly associated with low back pain (odds ratio, 1.78; 95% confidence interval, 1.13-2.80 compared to the wide minimum cross-sectional area group: minimum cross-sectional area greater than the third quartile measured).
  
  
  CONCLUSIONS
  This study showed that a narrow dural sac cross-sectional area was significantly associated with the presence of low back pain after adjustment for age, sex, and body mass index. Further investigations that include additional radiographic findings and psychological factors will continue to elucidate the causes of low back pain.
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Iwahashi
authors.affiliation: Department of Joint Disease Research, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoshimura
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashizume
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oka
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Matsudaira
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shinto
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Ishimoto
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Nagata
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Teraguchi
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Kagotani
authors.affiliation: Department of Joint Disease Research, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Muraki
authors.affiliation: Rehabilitation Services Bureau, National Rehabilitation Center for Persons with Disabilities, 1 Namiki 4-chome, Tokorozawa City, Saitama 359-8555, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Akune
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Sakae
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Japan Community Health Care Organization Tokyo Shinjuku Medical Center, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawaguchi
authors.affiliation: Rehabilitation Services Bureau, National Rehabilitation Center for Persons with Disabilities, 1 Namiki 4-chome, Tokorozawa City, Saitama 359-8555, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Minamide
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D019412:Anatomy, Cross-Sectional; D003430:Cross-Sectional Studies; D004388:Dura Mater / Q000473:pathology*; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis / Q000453:epidemiology; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013130:Spinal Stenosis / Q000175:diagnosis / Q000453:epidemiology