{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T07:25:15Z","timestamp":1791617115152,"version":"4.3.4"},"reference-count":28,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,8,1]]},"abstract":"\n OBJECTIVE<\/jats:title>\n The Ames\u2013International Spine Study Group (ISSG) classification is a tool for stratifying severity in adult cervical spine deformity. The Ames-ISSG sagittal modifiers include C2\u20137 sagittal vertical axis (cSVA), T1 slope\u2013cervical lordosis mismatch (TS-CL), and chin-brow vertical angle (CBVA). Each modifier stratifies patients as grade 0, 1, or 2. The study aimed to classify an asymptomatic population according to the Ames-ISSG sagittal modifier grades and assess differences in health-related quality of life (HRQOL) between grades.<\/jats:p>\n <\/jats:sec>\n \n METHODS<\/jats:title>\n A cross-sectional analysis of a prospectively collected database was performed. Five hundred healthy, asymptomatic volunteers between 20 and 40 years of age without prior surgery or diagnosed spinal pathology were enrolled and underwent EOS imaging to measure their Ames-ISSG sagittal modifiers (cSVA, TS-CL, and CBVA). HRQOL questionnaires (the Oswestry Disability Index and Neck Disability Index) were also completed.<\/jats:p>\n <\/jats:sec>\n \n RESULTS<\/jats:title>\n Four hundred seventy-seven patients were included. The cSVA was not analyzed because 475 of 477 individuals were grade 0 (< 4 cm). The TS-CL modifier was not analyzed because 472 of 477 individuals were grade 0 (< 15\u00b0). The CBVA was grade 0 (1\u00b0\u201310\u00b0) in 64% of individuals and grade 1 (\u221210\u00b0 to 0\u00b0 or 11\u00b0\u201325\u00b0) in 36%. There was no significant difference between grades in HRQOL.<\/jats:p>\n <\/jats:sec>\n \n CONCLUSIONS<\/jats:title>\n The Ames-ISSG classification sagittal modifiers cSVA and TS-CL grade 0 describe normal anatomy. A CBVA grade of 1 is present in 36% of asymptomatic individuals with no difference in HRQOL scores. This study validates the threshold for grade 0 in a normative population for TS-CL and cSVA. It also highlights inconsistency in CBVA and the importance of specific instructions for appropriate evaluation.<\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/2025.2.spine241153","type":"journal-article","created":{"date-parts":[[2025,6,6]],"date-time":"2025-06-06T22:23:14Z","timestamp":1749248594000},"page":"190-194","source":"Crossref","is-referenced-by-count":2,"title":["Application of the Ames\u2013International Spine Study Group radiographic modifiers to an asymptomatic population: are the thresholds for \"normal\" appropriate?"],"prefix":"10.3171","volume":"43","author":[{"given":"R\u00e9mi","family":"Pelletier-Roy","sequence":"first","affiliation":[{"name":"Department of Orthopedic Surgery, University of Calgary; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Richard","family":"Cowley","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Calgary; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taryn","family":"Ludwig","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Calgary; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew","family":"Coyle","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Calgary; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"W. Brent","family":"Edwards","sequence":"additional","affiliation":[{"name":"McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Alberta, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Asmussen","sequence":"additional","affiliation":[{"name":"McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Alberta, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fred","family":"Nicholls","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Calgary; and"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"issue":"6","key":"b1","series-title":"J Neurosurg Spine","first-page":"673","article-title":"Reliability assessment of a novel cervical spine deformity classification system","volume":"23","author":"Ames CP","year":"2015","unstructured":"Ames CP, Smith JS, Eastlack R, Reliability assessment of a novel cervical spine deformity classification system. J Neurosurg Spine. 2015;23(6):673\u2013683."},{"issue":"2","key":"b2","series-title":"Neurosurgery","first-page":"192","article-title":"Characterizing adult cervical deformity and disability based on existing cervical and adult deformity classification schemes at presentation and following correction","volume":"82","author":"Passias PG","year":"2018","unstructured":"Passias PG, Jalai CM, Smith JS, Characterizing adult cervical deformity and disability based on existing cervical and adult deformity classification schemes at presentation and following correction. Neurosurgery. 2018;82(2):192\u2013201."},{"key":"b3","series-title":"J Clin Neurosci","first-page":"297","article-title":"Improvement in some Ames-ISSG cervical deformity classification modifier grades may correlate with clinical improvement","volume":"89","author":"Horn SR","year":"2021","unstructured":"Horn SR, Passias PG, Passfall L, Improvement in some Ames-ISSG cervical deformity classification modifier grades may correlate with clinical improvement. J Clin Neurosci. 2021;89:297\u2013304."},{"issue":"5","key":"b4","series-title":"J Neurosurg Spine","first-page":"483","article-title":"Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?","volume":"29","author":"Bakouny Z","year":"2018","unstructured":"Bakouny Z, Khalil N, Otayek J, Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?. J Neurosurg Spine. 2018;29(5):483\u2013490."},{"issue":"4","key":"b5","series-title":"Spine (Phila Pa 1976).","first-page":"427","article-title":"Is there an optimal patient stance for obtaining a lateral 36\" radiograph? A critical comparison of three techniques","volume":"30","author":"Horton WC","year":"2005","unstructured":"Horton WC, Brown CW, Bridwell KH, Glassman SD, Suk SI, Cha CW. Is there an optimal patient stance for obtaining a lateral 36\" radiograph? A critical comparison of three techniques. Spine (Phila Pa 1976).2005;30(4):427\u2013433."},{"issue":"25","key":"b6","series-title":"Spine (Phila Pa 1976).","first-page":"E1648","article-title":"Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population","volume":"36","author":"Lee CS","year":"2011","unstructured":"Lee CS, Chung SS, Kang KC, Park SJ, Shin SK. Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population. Spine (Phila Pa 1976).2011;36(25):E1648\u2013E1654."},{"issue":"3","key":"b7","series-title":"Spine (Phila Pa 1976).","first-page":"346","article-title":"Classification of the normal variation in the sagittal alignment of the human lumbar spine and pelvis in the standing position","volume":"30","author":"Roussouly P","year":"2005","unstructured":"Roussouly P, Gollogly S, Berthonnaud E, Dimnet J. Classification of the normal variation in the sagittal alignment of the human lumbar spine and pelvis in the standing position. Spine (Phila Pa 1976).2005;30(3):346\u2013353."},{"issue":"23","key":"b8","series-title":"Spine (Phila Pa 1976).","first-page":"1837","article-title":"Variations in occipitocervical and cervicothoracic alignment parameters based on age: a prospective study of asymptomatic volunteers using full-body radiographs","volume":"41","author":"Iyer S","year":"2016","unstructured":"Iyer S, Lenke LG, Nemani VM, Variations in occipitocervical and cervicothoracic alignment parameters based on age: a prospective study of asymptomatic volunteers using full-body radiographs. Spine (Phila Pa 1976).2016;41(23):1837\u20131844."},{"issue":"1","key":"b9","series-title":"J Neurosurg Spine","first-page":"31","article-title":"Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis","volume":"30","author":"Staub BN","year":"2018","unstructured":"Staub BN, Lafage R, Kim HJ, Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis. J Neurosurg Spine. 2018;30(1):31\u201337."},{"issue":"17","key":"b10","series-title":"Spine (Phila Pa 1976).","first-page":"2001","article-title":"Significance of chin-brow vertical angle in correction of kyphotic deformity of ankylosing spondylitis patients","volume":"28","author":"Suk KS","year":"2003","unstructured":"Suk KS, Kim KT, Lee SH, Kim JM. Significance of chin-brow vertical angle in correction of kyphotic deformity of ankylosing spondylitis patients. Spine (Phila Pa 1976).2003;28(17):2001\u20132005."},{"issue":"1","key":"b11","series-title":"Neurosurgery","first-page":"108","article-title":"Natural head posture in the setting of sagittal spinal deformity: validation of chin-brow vertical angle, slope of line of sight, and McGregor\u2019s slope with health-related quality of life","volume":"79","author":"Lafage R","year":"2016","unstructured":"Lafage R, Challier V, Liabaud B, Natural head posture in the setting of sagittal spinal deformity: validation of chin-brow vertical angle, slope of line of sight, and McGregor\u2019s slope with health-related quality of life. Neurosurgery. 2016;79(1):108\u2013115."},{"issue":"suppl 1","key":"b12","series-title":"Neurosurgery","first-page":"S14","article-title":"The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery","volume":"76","author":"Tang JA","year":"2015","unstructured":"Tang JA, Scheer JK, Smith JS, The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery. Neurosurgery. 2015;76(suppl 1):S14-S21."},{"issue":"22)(suppl 1","key":"b13","series-title":"Spine (Phila Pa 1976).","first-page":"S149","article-title":"Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy","volume":"38","author":"Ames CP","year":"2013","unstructured":"Ames CP, Blondel B, Scheer JK, Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy. Spine (Phila Pa 1976).2013;38(22)(suppl 1):S149\u2013S160."},{"issue":"2","key":"b14","series-title":"J Neurosurg Spine","first-page":"141","article-title":"Cervical spine alignment, sagittal deformity, and clinical implications: a review","volume":"19","author":"Scheer JK","year":"2013","unstructured":"Scheer JK, Tang JA, Smith JS, Cervical spine alignment, sagittal deformity, and clinical implications: a review. J Neurosurg Spine. 2013;19(2):141\u2013159."},{"issue":"6","key":"b1","series-title":"J Neurosurg Spine","first-page":"673","article-title":"Reliability assessment of a novel cervical spine deformity classification system","volume":"23","author":"Ames CP","year":"2015","unstructured":"Ames CP, Smith JS, Eastlack R, Reliability assessment of a novel cervical spine deformity classification system. J Neurosurg Spine. 2015;23(6):673\u2013683."},{"issue":"2","key":"b2","series-title":"Neurosurgery","first-page":"192","article-title":"Characterizing adult cervical deformity and disability based on existing cervical and adult deformity classification schemes at presentation and following correction","volume":"82","author":"Passias PG","year":"2018","unstructured":"Passias PG, Jalai CM, Smith JS, Characterizing adult cervical deformity and disability based on existing cervical and adult deformity classification schemes at presentation and following correction. Neurosurgery. 2018;82(2):192\u2013201."},{"key":"b3","series-title":"J Clin Neurosci","first-page":"297","article-title":"Improvement in some Ames-ISSG cervical deformity classification modifier grades may correlate with clinical improvement","volume":"89","author":"Horn SR","year":"2021","unstructured":"Horn SR, Passias PG, Passfall L, Improvement in some Ames-ISSG cervical deformity classification modifier grades may correlate with clinical improvement. J Clin Neurosci. 2021;89:297\u2013304."},{"issue":"5","key":"b4","series-title":"J Neurosurg Spine","first-page":"483","article-title":"Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?","volume":"29","author":"Bakouny Z","year":"2018","unstructured":"Bakouny Z, Khalil N, Otayek J, Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?. J Neurosurg Spine. 2018;29(5):483\u2013490."},{"issue":"4","key":"b5","series-title":"Spine (Phila Pa 1976).","first-page":"427","article-title":"Is there an optimal patient stance for obtaining a lateral 36\" radiograph? A critical comparison of three techniques","volume":"30","author":"Horton WC","year":"2005","unstructured":"Horton WC, Brown CW, Bridwell KH, Glassman SD, Suk SI, Cha CW. Is there an optimal patient stance for obtaining a lateral 36\" radiograph? A critical comparison of three techniques. Spine (Phila Pa 1976).2005;30(4):427\u2013433."},{"issue":"25","key":"b6","series-title":"Spine (Phila Pa 1976).","first-page":"E1648","article-title":"Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population","volume":"36","author":"Lee CS","year":"2011","unstructured":"Lee CS, Chung SS, Kang KC, Park SJ, Shin SK. Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population. Spine (Phila Pa 1976).2011;36(25):E1648\u2013E1654."},{"issue":"3","key":"b7","series-title":"Spine (Phila Pa 1976).","first-page":"346","article-title":"Classification of the normal variation in the sagittal alignment of the human lumbar spine and pelvis in the standing position","volume":"30","author":"Roussouly P","year":"2005","unstructured":"Roussouly P, Gollogly S, Berthonnaud E, Dimnet J. Classification of the normal variation in the sagittal alignment of the human lumbar spine and pelvis in the standing position. Spine (Phila Pa 1976).2005;30(3):346\u2013353."},{"issue":"23","key":"b8","series-title":"Spine (Phila Pa 1976).","first-page":"1837","article-title":"Variations in occipitocervical and cervicothoracic alignment parameters based on age: a prospective study of asymptomatic volunteers using full-body radiographs","volume":"41","author":"Iyer S","year":"2016","unstructured":"Iyer S, Lenke LG, Nemani VM, Variations in occipitocervical and cervicothoracic alignment parameters based on age: a prospective study of asymptomatic volunteers using full-body radiographs. Spine (Phila Pa 1976).2016;41(23):1837\u20131844."},{"issue":"1","key":"b9","series-title":"J Neurosurg Spine","first-page":"31","article-title":"Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis","volume":"30","author":"Staub BN","year":"2018","unstructured":"Staub BN, Lafage R, Kim HJ, Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis. J Neurosurg Spine. 2018;30(1):31\u201337."},{"issue":"17","key":"b10","series-title":"Spine (Phila Pa 1976).","first-page":"2001","article-title":"Significance of chin-brow vertical angle in correction of kyphotic deformity of ankylosing spondylitis patients","volume":"28","author":"Suk KS","year":"2003","unstructured":"Suk KS, Kim KT, Lee SH, Kim JM. Significance of chin-brow vertical angle in correction of kyphotic deformity of ankylosing spondylitis patients. Spine (Phila Pa 1976).2003;28(17):2001\u20132005."},{"issue":"1","key":"b11","series-title":"Neurosurgery","first-page":"108","article-title":"Natural head posture in the setting of sagittal spinal deformity: validation of chin-brow vertical angle, slope of line of sight, and McGregor\u2019s slope with health-related quality of life","volume":"79","author":"Lafage R","year":"2016","unstructured":"Lafage R, Challier V, Liabaud B, Natural head posture in the setting of sagittal spinal deformity: validation of chin-brow vertical angle, slope of line of sight, and McGregor\u2019s slope with health-related quality of life. Neurosurgery. 2016;79(1):108\u2013115."},{"issue":"suppl 1","key":"b12","series-title":"Neurosurgery","first-page":"S14","article-title":"The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery","volume":"76","author":"Tang JA","year":"2015","unstructured":"Tang JA, Scheer JK, Smith JS, The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery. Neurosurgery. 2015;76(suppl 1):S14-S21."},{"issue":"22)(suppl 1","key":"b13","series-title":"Spine (Phila Pa 1976).","first-page":"S149","article-title":"Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy","volume":"38","author":"Ames CP","year":"2013","unstructured":"Ames CP, Blondel B, Scheer JK, Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy. Spine (Phila Pa 1976).2013;38(22)(suppl 1):S149\u2013S160."},{"issue":"2","key":"b14","series-title":"J Neurosurg Spine","first-page":"141","article-title":"Cervical spine alignment, sagittal deformity, and clinical implications: a review","volume":"19","author":"Scheer JK","year":"2013","unstructured":"Scheer JK, Tang JA, Smith JS, Cervical spine alignment, sagittal deformity, and clinical implications: a review. J Neurosurg Spine. 2013;19(2):141\u2013159."}],"container-title":["Journal of Neurosurgery: Spine"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-spine\/43\/2\/article-p190.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg-spine\/43\/2\/article-p190.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg-spine\/43\/2\/article-p190.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T13:44:03Z","timestamp":1772804643000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-spine\/43\/2\/article-p190.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,1]]},"references-count":28,"journal-issue":{"issue":"2"},"URL":"https:\/\/doi.org\/10.3171\/2025.2.spine241153","relation":{},"ISSN":["1547-5654"],"issn-type":[{"value":"1547-5654","type":"print"}],"subject":[],"published":{"date-parts":[[2025,8,1]]}}}