{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T12:06:40Z","timestamp":1787746000158,"version":"build-2784847793"},"reference-count":31,"publisher":"Wiley","issue":"12","license":[{"start":{"date-parts":[[2024,7,10]],"date-time":"2024-07-10T00:00:00Z","timestamp":1720569600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Knee surg. sports traumatol. arthrosc."],"published-print":{"date-parts":[[2024,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>Femorotibial angle (FTA) is a convenient measure of coronal knee alignment that can be extracted from a short knee radiograph, avoiding the additional radiation exposure and specialist equipment required for full\u2010leg radiographs. While intra\u2010 and inter\u2010reader reproducibility from the same image has been reported, the full scan\u2013rescan reproducibility across images, as calculated in this study, has not.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>In this study, 4589 FTA measurement pairs from 2586 subjects acquired a year apart were used to estimate FTA scan\u2013rescan reproducibility using data from the Osteoarthritis Initiative. Subjects with radiographic progression of osteoarthritis or other conditions that may cause a change in coronal knee alignment were excluded. Measurement pairs were analysed using paired\u2010samples\u00a0 tests to detect differences and compared to symptomatic changes in Western Ontario and McMaster Universities Arthritis Index scores for joint pain, stiffness\u00a0and physical function to detect correlations.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The 95% limit of agreement and the paired\u2010samples\u00a0correlation were calculated with high precision to be [\u22121.76\u00b0, +1.78\u00b0] and 0.938, considerably worse than the corresponding figures for intra\u2010 and inter\u2010reader reproducibility, without relation to symptomatic or radiographic changes in knee condition. This error will weakly attenuate  and  values from their true values in correlative studies involving FTA. The realistic maximum value for  is 87%\u00a0and for Pearson's  is 93%.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>The scan\u2013rescan reproducibility in FTA\u00a0is almost double the intra\u2010 and inter\u2010reader reliability from a single scan. At almost \u00b12\u00b0 accuracy, FTA is inappropriate for surgical use, but it is sufficiently reproducible to produce good correlations in studies predicting disease incidence and progression.<\/jats:p><\/jats:sec><jats:sec><jats:title>Level of Evidence<\/jats:title><jats:p>Level II, retrospective study.<\/jats:p><\/jats:sec>","DOI":"10.1002\/ksa.12352","type":"journal-article","created":{"date-parts":[[2024,7,10]],"date-time":"2024-07-10T09:25:14Z","timestamp":1720603514000},"page":"3133-3140","source":"Crossref","is-referenced-by-count":2,"title":["Femorotibial angle scan\u2013rescan reproducibility: A high\u2010precision calculation on a large cohort"],"prefix":"10.1002","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6695-1130","authenticated-orcid":false,"given":"Thomas A. G.","family":"Hall","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering Biomechanics Group, Imperial College London London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gareth G.","family":"Jones","sequence":"additional","affiliation":[{"name":"MSk Lab, Department of Surgery and Cancer Imperial College London London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1301-1337","authenticated-orcid":false,"given":"Richard J.","family":"van Arkel","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering Biomechanics Group, Imperial College London London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,7,10]]},"reference":[{"key":"e_1_2_12_2_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-030-24243-5_25"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/art.22515"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.1097\/CORR.0000000000000444"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.eclinm.2020.100587"},{"key":"e_1_2_12_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2012.09.012"},{"key":"e_1_2_12_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2009.05.012"},{"key":"e_1_2_12_8_1","doi-asserted-by":"publisher","DOI":"10.1080\/17453674.2020.1779516"},{"key":"e_1_2_12_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2014.06.011"},{"key":"e_1_2_12_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.arth.2023.01.060"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13018-022-03246-7"},{"key":"e_1_2_12_12_1","doi-asserted-by":"publisher","DOI":"10.1302\/2058-5241.6.210015"},{"key":"e_1_2_12_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2014.11.015"},{"key":"e_1_2_12_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2015.04.017"},{"key":"e_1_2_12_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2009.10.005"},{"key":"e_1_2_12_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2015.08.016"},{"key":"e_1_2_12_17_1","doi-asserted-by":"publisher","DOI":"10.3390\/jcm12041455"},{"key":"e_1_2_12_18_1","unstructured":"Nevitt M. 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