{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T20:48:25Z","timestamp":1785444505449,"version":"3.56.0"},"reference-count":17,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2021,9,3]],"date-time":"2021-09-03T00:00:00Z","timestamp":1630627200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2021,9,3]],"date-time":"2021-09-03T00:00:00Z","timestamp":1630627200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Spine Deform"],"published-print":{"date-parts":[[2022,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Introduction<\/jats:title>\n                <jats:p>Although matching lumbar lordosis (LL) with pelvic incidence (PI) is an important surgical goal for adult spinal deformity (ASD), there is concern that overcorrection may lead to proximal junctional kyphosis (PJK). We introduce the upper instrumented vertebra\u2013femoral angle (UIVFA) as a measure of appropriate postoperative position in the setting of lower thoracic to pelvis surgical correction for patients with sagittal imbalance. We hypothesize that a more posterior UIV position in relation to the center of the femoral head is associated with an increased risk of PJK given compensatory hyperkyphosis above the UIV.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>In this retrospective cohort study, adult patients undergoing lower thoracic (T9\u2013T12) to pelvis correction of ASD with a minimum of 2-year follow-up were included. UIVFA was measured as the angle subtended by a line from the UIV centroid to the femoral head center to the vertical axis. Patients who developed PJK and those who did not were compared with preoperative and postoperative UIVFA as well as change between postoperative and preoperative UIVFA (deltaUIVFA).<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Of 119 patients included with an average 3.6-year follow-up, 51 (42.9%) had PJK and 24 (20.2%) had PJF. Patients with PJK had significantly higher postoperative UIVFA (12.6\u2009\u00b1\u20094.8\u00b0 vs. 9.4\u2009\u00b1\u20096.6\u00b0, <jats:italic>p<\/jats:italic>\u2009=\u20090.04), deltaUIVFA (6.1\u2009\u00b1\u20097.6\u00b0 vs. 2.1\u2009\u00b1\u20095.6\u00b0, <jats:italic>p<\/jats:italic>\u2009&lt;\u20090.01), postoperative pelvic tilt (27.3\u2009\u00b1\u20099.2 vs. 23.3\u2009\u00b1\u200911, <jats:italic>p<\/jats:italic>\u2009=\u20090.04), postoperative lumbar lordosis (47.7\u2009\u00b1\u200913.9\u00b0 vs. 42.4\u2009\u00b1\u200913.1, <jats:italic>p<\/jats:italic>\u2009=\u20090.04) and postoperative thoracic kyphosis (44.9\u2009\u00b1\u200913.2 vs. 31.6\u2009\u00b1\u200918.8) than patients without PJK. With multivariate logistic regression, postoperative UIVFA and deltaUIVFA were found to be independent risk factors for PJK (<jats:italic>p<\/jats:italic>\u2009&lt;\u20090.05). DeltaUIVFA was found to be an independent risk factor for PJF (<jats:italic>p<\/jats:italic>\u2009&lt;\u20090.05). A receiver operating characteristic (ROC) curve for UIVFA as a predictor for PJK was established with an area under the curve of 0.67 (95% CI 0.59\u20130.76). Per the Youden index, the optimal UIVFA cut-off value is 11.5 degrees.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusion<\/jats:title>\n                <jats:p>The more posterior the UIV is from the femoral head center after lower thoracic to pelvis surgical correction for ASD, the more patients are at risk for PJK. The greater the magnitude of posterior translation of the UIV from the femoral head center from preop to postop, the greater the likelihood for PJF.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1007\/s43390-021-00408-1","type":"journal-article","created":{"date-parts":[[2021,9,3]],"date-time":"2021-09-03T21:49:30Z","timestamp":1630705770000},"page":"449-455","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Upper instrumented vertebra\u2013femoral angle and correlation with proximal junctional kyphosis in adult spinal deformity"],"prefix":"10.1007","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1048-3889","authenticated-orcid":false,"given":"Hao-Hua","family":"Wu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dean","family":"Chou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevork","family":"Hindoyan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeremy","family":"Guinn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua","family":"Rivera","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pingguo","family":"Duan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Minghao","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhuo","family":"Xi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bo","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Lee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shane","family":"Burch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Praveen","family":"Mummaneni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sigurd","family":"Berven","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2021,9,3]]},"reference":[{"issue":"5","key":"408_CR1","doi-asserted-by":"publisher","first-page":"318","DOI":"10.5435\/JAAOS-D-14-00393","volume":"24","author":"HJ Kim","year":"2016","unstructured":"Kim HJ, Iyer S (2016) Proximal junctional kyphosis. 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Eur Spine J 19(11):1824\u20131836. https:\/\/doi.org\/10.1007\/s00586-010-1476-9","journal-title":"Eur Spine J"}],"container-title":["Spine Deformity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s43390-021-00408-1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s43390-021-00408-1\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s43390-021-00408-1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,11]],"date-time":"2022-02-11T09:58:58Z","timestamp":1644573538000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s43390-021-00408-1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,3]]},"references-count":17,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2022,3]]}},"alternative-id":["408"],"URL":"https:\/\/doi.org\/10.1007\/s43390-021-00408-1","relation":{},"ISSN":["2212-134X","2212-1358"],"issn-type":[{"value":"2212-134X","type":"print"},{"value":"2212-1358","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,3]]},"assertion":[{"value":"21 January 2021","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"25 August 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"3 September 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors have no conflicts of interests directly tied to this investigation. For disclosures, Dr. Chou reports personal fees from Globus, outside the submitted work. Dr. Berven reports personal fees from Globus, Innovasis, Integrity Spine, grants from AOSpine, OMEGA, OREF, stocks from Globus, Green Sun Medical, Providence Medical, royalties from Medtronic, Medicrea, Stryker, editorial board\/committee membership for Bone and Joint Decade, NASS, SRS, JBJS, Journal of Neurosurgery, Orthopedics Today, Spinal Deformity, Spine, outside the submitted work. Dr. Burch reports personal fees from Medtronic and Zimmer outside the submitted work. Dr. Mummaneni reports personal fees from Depuy, Globus, and Stryker, grants from NREF, NIH, AOSpine, stocks from ISD, Spincity, royalties from Depuy, Theime Publishers, Springer Publishers outside the submitted work. Dr. Wu, Dr. Hindoyan, Mr. Guinn, Mr. Rivera, Dr. Duan, Dr. Wang, Dr. Xi, Dr. Li, and Dr. Lee have nothing to disclose.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}},{"value":"None. IRB-approved retrospective cohort study.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Informed consent"}},{"value":"Obtained for the study.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"IRB approval"}}]}}