{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T03:40:43Z","timestamp":1792122043739,"version":"4.4.0"},"reference-count":34,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T00:00:00Z","timestamp":1777939200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T00:00:00Z","timestamp":1777939200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["No. 82425036"],"award-info":[{"award-number":["No. 82425036"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["esskajournals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Knee surg. sports traumatol. arthrosc."],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Coronal plane alignment of the knee (CPAK) classification is widely used in total knee arthroplasty (TKA) planning, but its three\u2010dimensional (3D) relationship with sagittal and axial alignment remains unclear. This study aimed to investigate the association between the CPAK classification and 3D alignment parameters using EOS imaging.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      This single\u2010center retrospective cohort study included 1009 patients (511 non\u2010KOA; 498 KOA). All participants underwent EOS full\u2010body\/lower\u2010limb biplanar radiographs with 3D reconstruction. The CPAK classification and sagittal\/axial parameters were measured. Generalized linear models (GLMs) were used to compare parameters across CPAK types while controlling for age, sex, and BMI. Effect sizes were reported as partial eta\u2010squared (\n                      <jats:italic>\u03b7<\/jats:italic>\n                      \u00b2) with 95% confidence intervals obtained via bootstrap resampling. Associations between the arithmetic hip\u2013knee\u2013ankle angle (aHKA), joint line obliquity (JLO), and 3D parameters were assessed using partial Spearman correlation.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Most 3D parameters showed no statistically significant differences across CPAK types after adjusting for age, sex, and BMI. In the non\u2010KOA cohort, significant differences persisted for sagittal alignment (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001;\n                      <jats:italic>\u03b7<\/jats:italic>\n                      \u00b2\u2009=\u20090.116; 95% confidence interval [CI]: 0.069\u20131.000), the femoral torsion angle (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001;\n                      <jats:italic>\u03b7<\/jats:italic>\n                      \u00b2\u2009=\u20090.066; 95% CI: 0.029\u20131.000), and the femoro\u2010tibial rotation angle (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001;\n                      <jats:italic>\u03b7<\/jats:italic>\n                      \u00b2\u2009=\u20090.125; 95% CI: 0.078\u20131.000). In the KOA cohort, no parameters reached statistical significance after adjustment (all\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&gt;\u20090.05). The aHKA and JLO were significantly correlated with some 3D parameters, although all correlation coefficients were weak (\n                      <jats:italic>\u03c1<\/jats:italic>\n                      \u2009&lt;\u20090.30).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>The CPAK classification\u2032s weak correlation with most 3D parameters confirms its inherent limitations, accounting for limited sagittal and axial variance. Future phenotyping should integrate kinematic and soft tissue assessments for personalized TKA planning.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Level of Evidence<\/jats:title>\n                    <jats:p>Level III, retrospective cohort study.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/ksa.70407","type":"journal-article","created":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T12:27:12Z","timestamp":1777984032000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The coronal plane alignment of the knee (CPAK) classification has three\u2010dimensional limitations: Evidence from EOS imaging"],"prefix":"10.1002","author":[{"given":"Bo","family":"Wang","sequence":"first","affiliation":[{"name":"School of Medicine Nankai University Tianjin China"},{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; Rehabilitation Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Li","sequence":"additional","affiliation":[{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; Rehabilitation Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dengfa","family":"Gao","sequence":"additional","affiliation":[{"name":"Department of Radiology First Medical Center, Chinese PLA General Hospital Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yubo","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Medicine Nankai University Tianjin China"},{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; Rehabilitation Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiao","family":"Hou","sequence":"additional","affiliation":[{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; Rehabilitation Beijing China"},{"name":"Chinese PLA Medical School Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keyu","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Medicine Nankai University Tianjin China"},{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; Rehabilitation Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Lou","sequence":"additional","affiliation":[{"name":"Department of Radiology First Medical Center, Chinese PLA General Hospital Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8781-9745","authenticated-orcid":false,"given":"Wei","family":"Chai","sequence":"additional","affiliation":[{"name":"Senior Department of Orthopaedics The Fourth Medical Center of PLA General Hospital Beijing China"},{"name":"National Clinical Research Center for Orthopaedics, Sports Medicine &amp; 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A computed tomographic study indicates no significant correlation with alignment parameters in other planes","volume":"39","author":"Corbett J","year":"2024","journal-title":"J Arthroplasty"},{"key":"e_1_2_12_10_1","doi-asserted-by":"crossref","first-page":"S209","DOI":"10.1016\/j.arth.2023.03.065","article-title":"A randomized controlled trial of kinematically and mechanically aligned total knee arthroplasties: long\u2010term follow\u2010up","volume":"38","author":"Dossett HG","year":"2023","journal-title":"J Arthroplasty"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/jeo2.70409"},{"key":"e_1_2_12_12_1","doi-asserted-by":"crossref","DOI":"10.2106\/JBJS.L.00989","article-title":"EOS low\u2010dose radiography: a reliable and accurate upright assessment of lower\u2010limb lengths","volume":"95","author":"Escott BG","year":"2013","journal-title":"J Bone Joint 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Arthroplasty"},{"key":"e_1_2_12_17_1","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1302\/2633-1462.33.BJO-2022-0001.R1","article-title":"Validation and modification of the coronal plane alignment of the knee classification in the Asian population","volume":"3","author":"Hsu CE","year":"2022","journal-title":"Bone Jt Open"},{"key":"e_1_2_12_18_1","first-page":"96","article-title":"Reliability and concurrent validity of angle measurements in lower limb: EOS 3D goniometer versus 2D manual goniometer","volume":"24","author":"Huang J","year":"2020","journal-title":"J Orthop Transl"},{"key":"e_1_2_12_19_1","doi-asserted-by":"crossref","first-page":"4220","DOI":"10.1007\/s00167-023-07459-z","article-title":"Gender\u2010specific distribution of knee morphology according to CPAK and functional phenotype classification: analysis of 8739 osteoarthritic knees prior to total knee arthroplasty using artificial intelligence","volume":"31","author":"Huber S","year":"2023","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"key":"e_1_2_12_20_1","doi-asserted-by":"publisher","DOI":"10.1002\/jeo2.70039"},{"key":"e_1_2_12_21_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2106\/JBJS.22.00520","article-title":"Reference axes for tibial component rotation in total knee arthroplasty: computed tomography\u2010based study of 1,351 tibiae","volume":"105","author":"Jang ES","year":"2023","journal-title":"J Bone Jt Surg"},{"key":"e_1_2_12_22_1","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1186\/s40634-023-00697-7","article-title":"Definitions and consequences of current alignment techniques and phenotypes in total knee arthroplasty (TKA)\u2010there is no winner yet","volume":"10","author":"Karasavvidis T","year":"2023","journal-title":"J Exp Orthop"},{"key":"e_1_2_12_23_1","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1123\/pes.2015-0265","article-title":"Influence of exercise and training on critical stages of bone growth and development","volume":"28","author":"Klentrou P","year":"2016","journal-title":"Pediatr Exerc Sci"},{"key":"e_1_2_12_24_1","first-page":"875","article-title":"[Introduction of EOS imaging system and its current research status in evaluating clinical value of lower limb force line]","volume":"32","author":"Li Q","year":"2019","journal-title":"Zhong Shang = China J Orthop Traumatol"},{"issue":"19","key":"e_1_2_12_25_1","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1051\/sicotj\/2021021","article-title":"Personalized alignment in total knee arthroplasty: current concepts","volume":"7","author":"Lustig S","year":"2021","journal-title":"SICOT\u2010J"},{"key":"e_1_2_12_26_1","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1302\/0301-620X.103B2.BJJ-2020-1050.R1","article-title":"Coronal Plane Alignment of the Knee (CPAK) classification: a new system for describing knee phenotypes","volume":"103","author":"MacDessi SJ","year":"2021","journal-title":"Bone Jt J"},{"key":"e_1_2_12_27_1","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.jor.2025.08.041","article-title":"Phenotyping the knee joint \u2010 a narrative review of current literature","volume":"71","author":"Mengis N","year":"2026","journal-title":"J Orthop"},{"key":"e_1_2_12_28_1","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.jor.2024.01.008","article-title":"Posterior tibial slope considered as an important addition to the CPAK classification system","volume":"51","author":"Morrisey Z","year":"2024","journal-title":"J Orthop"},{"key":"e_1_2_12_29_1","doi-asserted-by":"crossref","first-page":"1362","DOI":"10.1007\/s00167-021-06605-9","article-title":"Posterior tibial slope measurements based on the full\u2010length tibial anatomic axis are significantly increased compared to those based on the half\u2010length tibial anatomic axis","volume":"30","author":"Ni QK","year":"2022","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"key":"e_1_2_12_30_1","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1002\/ksa.12013","article-title":"The neglected factor of constitutional sagittal alignment and its implications for total knee arthroplasty","volume":"32","author":"Sadoghi P","year":"2024","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"key":"e_1_2_12_31_1","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1007\/s00402-025-06044-y","article-title":"Beyond the CPAK dogma: robotic FA preserves CPAK better than MA but with equivalent proms at 5\u2010year follow\u2010up","volume":"145","author":"Sangaletti R","year":"2025","journal-title":"Arch Orthop Trauma Surg"},{"key":"e_1_2_12_32_1","doi-asserted-by":"crossref","first-page":"2806","DOI":"10.1007\/s00167-021-06674-w","article-title":"Mechanical alignment for primary TKA may change both knee phenotype and joint line obliquity without influencing clinical outcomes: a study comparing restored and unrestored joint line 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