{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T15:40:32Z","timestamp":1774712432111,"version":"3.50.1"},"reference-count":28,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,12,15]],"date-time":"2020-12-15T00:00:00Z","timestamp":1607990400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["16ek0109136h0002"],"award-info":[{"award-number":["16ek0109136h0002"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Health and Labour Science Research grants","award":["201610008B"],"award-info":[{"award-number":["201610008B"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>This study aimed to clarify whether ossification predisposition influences clinical symptoms including pain, restriction of activities of daily living, and quality of life in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Cervical ossification predisposition potentially causes neurologic dysfunction, but the relationship between clinical symptoms and radiologic severity of OPLL has not yet been investigated. Data were prospectively collected from 16 institutions across Japan. We enrolled 239 patients with cervical OPLL. The primary outcomes were patient-reported outcomes, including visual analog scale (VAS) pain scores and other questionnaires. Whole-spine computed tomography images were obtained, and correlations were investigated between clinical symptoms and radiologic findings, including the distribution of OPLL, the sum of the levels where OPLL was present (OP-index), and the canal narrowing ratio (CNR) grade. The cervical OP-index was Grade 1 in 113 patients, Grade 2 in 90, and Grade 3 in 36. No significant correlations were found between radiologic outcomes and VAS pain scores. The cervical OP-index was associated with lower extremity function, social dysfunction, and locomotive function. The CNR grade was not correlated with clinical symptoms, but Grade 4 was associated with lower extremity dysfunction. Thickness and extension of ossified lesions may be associated with lower extremity dysfunction in cervical OPLL.<\/jats:p>","DOI":"10.3390\/jcm9124055","type":"journal-article","created":{"date-parts":[[2020,12,15]],"date-time":"2020-12-15T21:11:02Z","timestamp":1608066662000},"page":"4055","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Associations between Clinical Symptoms and Degree of Ossification in Patients with Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multi-Institutional Cross-Sectional Study"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6200-0100","authenticated-orcid":false,"given":"Takashi","family":"Hirai","sequence":"first","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Toshitaka","family":"Yoshii","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5422-7655","authenticated-orcid":false,"given":"Shuta","family":"Ushio","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jun","family":"Hashimoto","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kanji","family":"Mori","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopaedic Surgery, Shiga University of Medical Science, Shiga 520-2192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Satoshi","family":"Maki","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba 260-0856, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3997-3593","authenticated-orcid":false,"given":"Keiichi","family":"Katsumi","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Niigata University Medical and Dental General Hospital, Niigata 951-8520, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Narihito","family":"Nagoshi","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazuhiro","family":"Takeuchi","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, National Hospital Organization Okayama Medical Center, Okayama 701-1192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takeo","family":"Furuya","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba 260-0856, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kei","family":"Watanabe","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Niigata University Medical and Dental General Hospital, Niigata 951-8520, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Norihiro","family":"Nishida","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Soraya","family":"Nishimura","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4830-4690","authenticated-orcid":false,"given":"Kota","family":"Watanabe","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4882-2997","authenticated-orcid":false,"given":"Takashi","family":"Kaito","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4762-5932","authenticated-orcid":false,"given":"Satoshi","family":"Kato","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Ishikawa 920-1192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katsuya","family":"Nagashima","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki 305-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masao","family":"Koda","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki 305-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kenyu","family":"Ito","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Aichi 464-8601, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shiro","family":"Imagama","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Aichi 464-8601, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuji","family":"Matsuoka","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Tokyo Medical University, Tokyo 160-8402, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kanichiro","family":"Wada","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Hirosaki University Graduate School of Medicine, Aomori 036-8562, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4948-1792","authenticated-orcid":false,"given":"Atsushi","family":"Kimura","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedics, Jichi Medical University, Tochigi 329-0498, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tetsuro","family":"Ohba","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, University of Yamanashi, Yamanashi 400-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0046-3008","authenticated-orcid":false,"given":"Hiroyuki","family":"Katoh","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa 259-1193, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9038-0446","authenticated-orcid":false,"given":"Masahiko","family":"Watanabe","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa 259-1193, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yukihiro","family":"Matsuyama","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Shizuoka 431-3125, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6991-0948","authenticated-orcid":false,"given":"Hiroshi","family":"Ozawa","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopaedic Surgery, Tohoku Medical and Pharmaceutical University, Miyagi 981-8558, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5630-9600","authenticated-orcid":false,"given":"Hirotaka","family":"Haro","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, University of Yamanashi, Yamanashi 400-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katsushi","family":"Takeshita","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedics, Jichi Medical University, Tochigi 329-0498, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Morio","family":"Matsumoto","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masaya","family":"Nakamura","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9293-3531","authenticated-orcid":false,"given":"Masashi","family":"Yamazaki","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki 305-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masato","family":"Yuasa","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4195-2545","authenticated-orcid":false,"given":"Hiroyuki","family":"Inose","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsushi","family":"Okawa","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo 113-8510, Japan"},{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoshiharu","family":"Kawaguchi","sequence":"additional","affiliation":[{"name":"Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Tokyo 113-8510, Japan"},{"name":"Department of Orthopedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-8555, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"820","DOI":"10.1177\/2192568219833658","article-title":"Cervical ossification of the posterior longitudinal ligament: A computed tomography-based epidemiological study of 2917 patients","volume":"9","author":"Bakhsh","year":"2019","journal-title":"Glob. Spine J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"432","DOI":"10.1097\/00002517-199306050-00011","article-title":"The surgical management of ossification of the posterior longitudinal ligament in 51 patients","volume":"6","author":"Epstein","year":"1993","journal-title":"J. Spinal Disord."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"E9","DOI":"10.3171\/2013.4.FOCUS1394","article-title":"Is there a difference in range of motion, neck pain, and outcomes in patients with ossification of posterior longitudinal ligament versus those with cervical spondylosis, treated with plated laminoplasty?","volume":"35","author":"Fujimori","year":"2013","journal-title":"Neurosurg. Focus"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1007\/s00776-009-1337-8","article-title":"JOA back pain evaluation questionnaire (JOABPEQ)\/JOA cervical myelopathy evaluation questionnaire (JOACMEQ). 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Int."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/12\/4055\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:45:31Z","timestamp":1760179531000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/12\/4055"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,15]]},"references-count":28,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["jcm9124055"],"URL":"https:\/\/doi.org\/10.3390\/jcm9124055","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,15]]}}}