{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T12:44:01Z","timestamp":1790858641310,"version":"4.1.0"},"reference-count":33,"publisher":"SAGE Publications","issue":"8","license":[{"start":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T00:00:00Z","timestamp":1783382400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"funder":[{"name":"internal institutional seed"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Foot Ankle Int."],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>The Progressive Collapsing Foot Deformity (PCFD) classification categorizes deformity patterns into 5 classes (A, hindfoot valgus; B, midfoot\/forefoot abduction; C, medial column collapse; D, peritalar subluxation; E, ankle valgus). Currently, the classifying process relies on surgeons' experience and interpretation of clinical and radiographic measurements. The goal of the present study was to establish cut-off threshold values for commonly used PCFD measurements assessing class A to D, using 2 large cohorts of PCFD patients and controls.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>This prospective comparative diagnostic study included 154 neutrally aligned or asymptomatic flatfoot volunteers (103 females, mean age 41.7\u2009years, body mass index [BMI] 28.9) and 321 PCFD patients (136 females, mean age 50.7\u2009years, BMI 29.8). Participants underwent weight-bearing computed tomography (WBCT). Measurements were obtained after blinded segmentation and included hindfoot moment arm (HMA, class A), talonavicular coverage angle (TNCA) and talus-first metatarsal angle axial (TFMA-A, class B), talus-first metatarsal angle sagittal (TFMA-S) and forefoot arch angle (FAA, class C), and coverage maps (middle facet [MF], posterior facet [PF], sinus tarsi [ST], class D). Receiver operating characteristic curves, Youden indexes, and areas under the curves (AUCs) identified optimal cut-offs. A partition prediction model refined those values, and a multivariate analysis identified independent predictors of symptomatic PCFD.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      Optimal cut-off values (all\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      \u2009&lt;\u2009.0001) included the following: HMA\u2009\u2265\u200913.9\u2009mm (AUC 85.3%, class A); TNCA\u2009\u2265\u200938.7\u00b0 (AUC 84.4%) and TFMA-A\u2009\u2265\u200920.3\u00b0 (AUC 82.1%, class B); FAA\u2009\u2264\u20098.7\u00b0 (AUC 83.9%) and TFMA-S\u2009\u2265\u200918.7\u00b0 (AUC 82.9%, class C); MF coverage\u2009\u2264\u200973.5% (AUC 73.4%), PF coverage\u2009\u2264\u200984.5% (AUC 82.7%), and ST coverage\u2009\u2265\u200925.7% (AUC 84.4%, class D). HMA, TNCA, MF, and ST coverages were identified as independent predictors of PCFD.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>This study established robust cut-off values for PCFD measurements across classes A-D using large comparative cohorts, significantly enhancing diagnostic performance (AUC\u2009\u2265\u200980% for most). These thresholds improve the clinical applicability and reliability of the PCFD classification, supporting clinical and surgical decision making and facilitating future comparative research.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Level of Evidence:<\/jats:title>\n                    <jats:p>Level II, prospective comparative diagnostic study.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/10711007261449247","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:42:10Z","timestamp":1783428130000},"page":"1048-1060","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Defining Radiographic Threshold Values for the Progressive Collapsing Foot Deformity Classification System: A Large-Cohort Diagnostic Study"],"prefix":"10.1177","volume":"47","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7387-1403","authenticated-orcid":false,"given":"Rebekah","family":"Belayneh","sequence":"first","affiliation":[{"name":"Hospital for Special Surgery, New York, NY"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0163-6516","authenticated-orcid":false,"given":"Fran\u00e7ois","family":"Lintz","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Duke University, Durham, NC, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1067-727X","authenticated-orcid":false,"given":"Nacime Salom\u00e3o Barbachan","family":"Mansur","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Duke University, Durham, NC, USA"},{"name":"Department of Orthopedics and Rehabilitation, Carver College of Medicine, University of Iowa (UIOWA), Iowa City, IA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0018-6410","authenticated-orcid":false,"given":"Grayson","family":"Talaski","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Rehabilitation, Carver College of Medicine, University of Iowa (UIOWA), Iowa City, IA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1640-6107","authenticated-orcid":false,"given":"Donald","family":"Anderson","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Rehabilitation, Carver College of Medicine, University of Iowa (UIOWA), Iowa City, IA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4304-7445","authenticated-orcid":false,"given":"Scott J.","family":"Ellis","sequence":"additional","affiliation":[{"name":"Hospital for Special Surgery, New York, NY"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6037-0685","authenticated-orcid":false,"given":"Cesar","family":"de Cesar Netto","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Duke University, Durham, NC, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,7,7]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1177\/10711007221141898"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.fcl.2007.03.003"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1177\/1071100712460225"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1097\/BTF.0000000000000164"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1177\/1938640020951050"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1177\/10711007231192479"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.2106\/JBJS.24.01619"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1177\/1071100720950715"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.2106\/JBJS.16.01366"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.5435\/00124635-200807000-00005"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1177\/1071100720983227"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kwh071"},{"issue":"2","key":"e_1_3_2_14_2","first-page":"8","article-title":"Deformities influencing different classes in progressive collapsing foot","volume":"43","author":"Fayed A","year":"2023","unstructured":"Fayed A, Mallavarapu V, Schmidt E, et al. Deformities influencing different classes in progressive collapsing foot. Iowa Orthop J. 2023;43(2):8-13.","journal-title":"Iowa Orthop J"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.3113\/FAI.2008.0199"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1177\/24730114261422230"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1053\/j.jfas.2004.09.013"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1097\/00003086-198902000-00022"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1177\/1471082x0700700304"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1177\/10711007221099010"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1177\/1071100718768020"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00402-021-04279-z"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1177\/10711007211058154"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1177\/10711007221078000"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1053\/j.jfas.2025.06.008"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00256-021-03942-1"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.2106\/JBJS.OA.23.00025"},{"key":"e_1_3_2_28_2","first-page":"105","volume-title":"Frontiers in Econometrics","author":"McFadden D","unstructured":"McFadden D. Quantitative methods for analyzing travel behavior of individuals: some recent developments. In: Zarembka P, ed. Frontiers in Econometrics. Academic Press; 1979:105-142."},{"key":"e_1_3_2_29_2","first-page":"393","article-title":"Adult acquired flatfoot deformity: treatment of dysfunction of the posterior tibial tendon","volume":"46","author":"Myerson MS.","year":"1997","unstructured":"Myerson MS. Adult acquired flatfoot deformity: treatment of dysfunction of the posterior tibial tendon. Instructional course lectures 1997;46:393-405.","journal-title":"Instructional course lectures"},{"key":"e_1_3_2_30_2","doi-asserted-by":"publisher","DOI":"10.1177\/1071100720950722"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-95708-x"},{"key":"e_1_3_2_32_2","doi-asserted-by":"publisher","DOI":"10.1177\/107110079501600911"},{"key":"e_1_3_2_33_2","doi-asserted-by":"publisher","DOI":"10.1177\/107110079301400305"},{"key":"e_1_3_2_34_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.3287615"}],"container-title":["Foot &amp; Ankle International"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10711007261449247","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/10711007261449247","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10711007261449247","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T06:45:36Z","timestamp":1786949136000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/10711007261449247"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,7]]},"references-count":33,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["10.1177\/10711007261449247"],"URL":"https:\/\/doi.org\/10.1177\/10711007261449247","relation":{},"ISSN":["1071-1007","1944-7876"],"issn-type":[{"value":"1071-1007","type":"print"},{"value":"1944-7876","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,7]]}}}