The Association between the Cross-Sectional Area of the Dural Sac and Low Back Pain in a Large Population: The Wakayama Spine Study

Hiroki Iwahashi; Noriko Yoshimura; Hiroshi Hashizume; Hiroshi Yamada; Hiroyuki Oka; Ko Matsudaira; Kazunori Shinto; Yuyu Ishimoto; Keiji Nagata; Masatoshi Teraguchi; Ryohei Kagotani; Shigeyuki Muraki; Toru Akune; Sakae Tanaka; Hiroshi Kawaguchi; Kozo Nakamura; Akihito Minamide; Yukihiro Nakagawa; Munehito Yoshida

doi:10.1371/journal.pone.0160002

The Association between the Cross-Sectional Area of the Dural Sac and Low Back Pain in a Large Population: The Wakayama Spine Study

PLoS One. 2016 Aug 3;11(8):e0160002. doi: 10.1371/journal.pone.0160002. eCollection 2016.

Authors

Hiroki Iwahashi¹, Noriko Yoshimura², Hiroshi Hashizume¹, Hiroshi Yamada¹, Hiroyuki Oka³, Ko Matsudaira³, Kazunori Shinto¹, Yuyu Ishimoto¹, Keiji Nagata¹, Masatoshi Teraguchi¹, Ryohei Kagotani¹, Shigeyuki Muraki², Toru Akune⁴, Sakae Tanaka⁵, Hiroshi Kawaguchi⁶, Kozo Nakamura⁴, Akihito Minamide¹, Yukihiro Nakagawa¹, Munehito Yoshida¹

Affiliations

¹ Department of Orthopaedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8510, Japan.
² 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.
³ 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.
⁴ Rehabilitation Services Bureau, National Rehabilitation Center for Persons with Disabilities, 1 Namiki 4-chome, Tokorozawa City, Saitama 359-8555, Japan.
⁵ Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
⁶ Japan Community Health Care Organization Tokyo Shinjuku Medical Center, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.

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).

Conclusion: 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.

MeSH terms

Anatomy, Cross-Sectional
Cross-Sectional Studies
Dura Mater / pathology*
Female
Humans
Intervertebral Disc / pathology*
Intervertebral Disc Degeneration / diagnosis
Intervertebral Disc Degeneration / epidemiology
Low Back Pain / diagnosis*
Low Back Pain / epidemiology
Low Back Pain / pathology*
Magnetic Resonance Imaging / methods
Male
Middle Aged
Prevalence
Spinal Stenosis / diagnosis
Spinal Stenosis / epidemiology

Grants and funding

This study was supported by H23-Choujyu-002 (Director, TA), H-25-Choujyu-007 (Director, NY), H25-Nanchitou (Men)-005 (Director, ST), 201417014A (Director, NY), and H22-Choujyu-Wakate-007 (Director, SM) from the Ministry of Health, Labour and Welfare, [URL:http://www.mhlw.go.jp/]; a Grant-in-Aid for Scientific Research (B26293139, B23390172 to NY, B2629333, C20591774 to SM, C26462249 to HH, C25462305 to HY) and a Grant-in-Aid for Young Researcher (B25860448 to YI, B26861286 to MT, B26860419 to RK, B15K20013 to HI); and Grant-in-Aid for Challenging Exploratory Research (15K15219 to NY, 26670307 to SM, 24659666 to HO, 25670293 to TA) of JSPS KAKENHI grant, [URL:https://www.jsps.go.jp/j-grantsinaid/]; a Grant from the Japanese Orthopaedics and Traumatology Foundation, Inc. (No. 287) to MT, [URL:http://jotf.jp/invitation.html]; and Collaborating Research with NSF 08033011-00262 (Director, NY) from the Ministry of Education, Culture, Sports, Science and Technology in Japan, [URL:http://www.mext.go.jp/english/]. This study also was supported by grants from the Japan Osteoporosis Society (NY, SM, HO, and TA), [URL:http://www.josteo.com/ja/index.html]; a grant from JA Kyosai Research Institute (HO), [URL:http://www.jkri.or.jp/]; grants from Mitsui Sumitomo Insurance Welfare Foundation (SM), [URL:http://www.ms-ins.com/welfare/index.htm]; research aid from the Japanese Orthopaedic Association (JOA-Subsidized Science Project Research 2006-1 & 2010-2; Director, HK), [URL:https://www.joa.or.jp/english/english_frame.html]; and Japan Society for the Promotion of Science a Grant-in-Aid for Scientific Research (C26462249) to Hiroshi Hashizume. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.