title: Prevalence and distribution of ossification of the supra/interspinous ligaments in symptomatic patients with cervical ossification of the posterior longitudinal ligament of the spine: a CT-based multicenter cross-sectional study.
abstract: Supra/interspinous ligaments connect adjacent spinous processes and act as a stabilizer of the spine. As with other spinal ligaments, it can become ossified. However, few report have discussed ossification supra/interspinous ligaments (OSIL), so its epidemiology remains unknown. We therefore aimed to investigate the prevalence and distribution of OSIL in symptomatic patients with cervical ossification of the posterior longitudinal ligament (OPLL).
  
  
  
  The participants of our study were symptomatic patients with cervical OPLL who were diagnosed by standard radiographs of the cervical spine. The whole spine CT data as well as clinical parameters such as age and sex were obtained from 20 institutions belong to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament (JOSL). The prevalence and distribution of OSIL and the association between OSIL and clinical parameters were reviewed. The sum of the levels involved by OPLL (OP-index) and OSIL (OSI-index) as well as the prevalence of ossification of the nuchal ligament (ONL) were also investigated.
  
  
  
  A total of 234 patients with a mean age of 65 years was recruited. The CT-based evidence of OSIL was noted in 68 (54 males and 14 females) patients (29%). The distribution of OSIL showed a significant thoracic preponderance. In OSIL-positive patients, single-level involvement was noted in 19 cases (28%), whereas 49 cases (72%) presented multi-level involvement. We found a significant positive correlation between the OP-index grade and OSI-index. ONL was noted at a significantly higher rate in OSIL-positive patients compared to negative patients.
  
  
  
  The prevalence of OSIL in symptomatic patients with cervical OPLL was 29%. The distribution of OSIL showed a significant thoracic preponderance.
authors.affiliation: Department of Orthopaedic Surgery, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga, 520-2192, Japan. kanchi@belle.shiga-med.ac.jp.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan. kanchi@belle.shiga-med.ac.jp.
authors.forename: Kanji
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8519, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Yoshii
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8519, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Iwanami
authors.affiliation: Department of Orthopedic Surgery, National Hospital Organization Okayama Medical Center, 1711-1Tamasu, Okayama, 701-1154, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takeuchi
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8519, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Orthopedic Surgery, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Seki
authors.affiliation: Department of Orthopedic Surgery, Kitasato Institute Hospital, 5-9-1, Shirokane, Minato-ku, Tokyo, 108-8642, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Department of Orthopedic Surgery, National Hospital Organization Murayama Medical Center, 2-37-1, Gakuen, Musashimurayama, Tokyo, 208-0011, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Kanehiro
authors.initials: K
authors.lastname: Fujiyoshi
authors.affiliation: Department of Orthopedic Surgery, Keiyu Hospital, 3-7-3, Minatomirai, Nishi-Ku, Yokohama, Kanagawa, 220-8521, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Furukawa
authors.affiliation: Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.|Department of Orthopedic Surgery, Keiyu Hospital, 3-7-3, Minatomirai, Nishi-Ku, Yokohama, Kanagawa, 220-8521, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Soraya
authors.initials: S
authors.lastname: Nishimura
authors.affiliation: Department of Orthopedic Surgery, Hirosaki University Graduate School of Medicine, 53 Honcho, Hirosaki, Aomori, 036-8203, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Kanichiro
authors.initials: K
authors.lastname: Wada
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo Ward, Chiba, 260-0856, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Koda
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo Ward, Chiba, 260-0856, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Furuya
authors.affiliation: Department of Orthopedic Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka, 431-3125, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Department of Orthopedic Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka, 431-3125, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Orthopedics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takeshita
authors.affiliation: Department of Orthopedics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kimura
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medicine and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abematsu
authors.affiliation: Department of Orthopedic Surgery, University of Yamanashi, 1110 Shimokato, Chuo Ward, Yamanashi, 409-3898, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Haro
authors.affiliation: Department of Orthopedic Surgery, University of Yamanashi, 1110 Shimokato, Chuo Ward, Yamanashi, 409-3898, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ohba
authors.affiliation: Department of Orthopedic Surgery, Surgical Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1143, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Orthopedic Surgery, Surgical Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1143, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Katoh
authors.affiliation: Department of Orthopedic Surgery, Niigata University Medicine and Dental General Hospital, 1-754 Asahimachidori, Chuo Ward, Niigata, 951-8520, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Orthopaedic Surgery, Tohoku Medical and Pharmaceutical University, 1-12-1 Fukumuro Miyaginoku, Sendai, 983-8512, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ozawa
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, 1-1 Seiryomachi, AobaWard, Sendai, Miyagi, 980-8574, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Kanno
authors.affiliation: Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumaicho, Showa Ward, Nagoya, Aichi, 466-0065, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Imagama
authors.affiliation: Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumaicho, Showa Ward, Nagoya, Aichi, 466-0065, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Zenya
authors.initials: Z
authors.lastname: Ito
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Fujibayashi
authors.affiliation: Department of Orthopedic Surgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8519, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okawa
authors.affiliation: Department of Orthopedic Surgery, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.|Japanese organization of the Study for Ossification of Spinal Ligament (JOSL), Otsu, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008023:Ligaments, Articular / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015995:Prevalence; D011859:Radiography; D013904:Thoracic Vertebrae; D014057:Tomography, X-Ray Computed
keywords: Ankylosed spine; Computed tomography; DISH; Epidemiology; OLF; OPLL; Ossification; Prevalence; Supra/interspinous ligaments; Whole spine