{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T06:30:50Z","timestamp":1786516250176,"version":"build-2736575974"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T00:00:00Z","timestamp":1786492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To investigate the incidence and risk factors of thumb posterior rotation deformity in children with thumb polydactyly.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A retrospective analysis was conducted on the clinical data of 479 patients (521 thumbs, mean age 13.1\u2009\u00b1\u200912.7 months) with thumb polydactyly. Clinical data including gender, age, and affected side were collected. Clinical appearance photographs and x-ray images of all patients were obtained. Thumb posterior rotation deformity was determined on clinical appearance photographs. The ulnar deviation angle of the thumb was measured on anteroposterior thumb radiographs.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      According to the Wassel classification, 13 thumbs (2.5%) were Type I, 55 thumbs (10.6%) Type II, 92 thumbs (17.7%) Type III, 186 thumbs (35.7%) Type IV, 138 thumbs (26.5%) Type V, 34 thumbs (6.5%) Type VI, and 3 thumbs (0.6%) Type VII. According to the Wu classification, 222 thumbs (42.6%) were type A, 27 thumbs (5.2%) were type B, 121 thumbs (23.2%) were type C, and 151 thumbs (29%) were type D. A total of 35 hands (6.7%) presented with varying degrees of thumb posterior rotation deformity, with a mean rotational angle of 14.1\u00b0\u00b19.0\u00b0 (range, 5\u00b0\u201330\u00b0). Wassel classification and Wu classification were correlated with the incidence of thumb posterior rotation deformity. Patients with thumb posterior rotation deformity had a significantly larger ulnar deviation angle of the thumb (19.3\u00b0\u00b117.5\u00b0) than those without (11.4\u00b0\u00b115.7\u00b0). Logistic regression analysis demonstrated that both the level and the type of the bifurcation of the duplicated thumb and ulnar deviation angle of the thumb were independent risk factors for the occurrence of thumb posterior rotation deformity (\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.05).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Thumb posterior rotation deformity is a common malformation in pediatric thumb polydactyly. The incidence of thumb posterior rotation deformity is significantly increased in patients with Wassel types IV, V, and VI thumb polydactyly, and thumb ulnar deviation also significantly elevates the risk of thumb posterior rotation deformity.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fped.2026.1894739","type":"journal-article","created":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T05:55:36Z","timestamp":1786514136000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Thumb posterior rotation deformity: a neglected deformity in children with thumb polydactyly"],"prefix":"10.3389","volume":"14","author":[{"given":"ZiHua","family":"Lin","sequence":"first","affiliation":[{"name":"Department of Orthopaedics Surgery, Heyuan Women & Children's Hospital and Health Institute","place":["Heyuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lin","family":"Ye","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics Surgery, Heyuan Women & Children's Hospital and Health Institute","place":["Heyuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"LiuQing","family":"Liao","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"DiHao","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"XueMei","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"WeiZhe","family":"Shi","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"JianQun","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"YiQiang","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,12]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"e21","DOI":"10.2106\/JBJS.RVW.21.00214","article-title":"Radial polydactyly","volume":"10","author":"Khabyeh-Hasbani","year":"2022","journal-title":"JBJS Rev"},{"key":"B2","first-page":"175","article-title":"The results of surgery for polydactyly of the thumb. A review","volume":"64","author":"Wassel","year":"1969","journal-title":"Clin Orthop Relat Res"},{"key":"B3","doi-asserted-by":"publisher","first-page":"190","DOI":"10.1097\/BPO.0b013e3182648ca8","article-title":"Radial polydactyly: proposal for a new classification system based on the 159 duplicated thumbs","volume":"33","author":"Chung","year":"2013","journal-title":"J Pediatr Orthop"},{"key":"B4","doi-asserted-by":"publisher","first-page":"275.e271","DOI":"10.1016\/j.jhsa.2022.06.001","article-title":"Modified radiographic classification system for congenital thumb duplication: an analysis of 2,300 thumbs in 2,108 children","volume":"49","author":"Wu","year":"2024","journal-title":"J Hand Surg Am"},{"key":"B5","doi-asserted-by":"publisher","first-page":"e1589","DOI":"10.1097\/GOX.0000000000001589","article-title":"A modified bilhaut-cloquet procedure for Zigzag thumb polydactyly types III and IV","volume":"5","author":"Al-Qattan","year":"2017","journal-title":"Plast Reconstr Surg Glob Open"},{"key":"B6","doi-asserted-by":"publisher","first-page":"272","DOI":"10.1177\/1753193412460809","article-title":"Correction of Wassel type IV thumb duplication with zigzag deformity: results of a new method of flexor pollicis longus tendon relocation","volume":"38","author":"Lee","year":"2013","journal-title":"J Hand Surg Eur"},{"key":"B7","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1002\/jez.1402490110","article-title":"Mammalian limb bud development: in situ fate maps of early hindlimb buds","volume":"249","author":"Muneoka","year":"1989","journal-title":"J Exp Zool"},{"key":"B8","first-page":"249","article-title":"Principles of hand ontogenesis in man","volume":"24","author":"Christ","year":"1986","journal-title":"Acta Morphol Neerl Scand"},{"key":"B9","doi-asserted-by":"publisher","first-page":"683","DOI":"10.1016\/S0749-0712(21)00735-6","article-title":"Anatomy of the joints of the thumb","volume":"8","author":"Barmakian","year":"1992","journal-title":"Hand Clin"},{"key":"B10","doi-asserted-by":"publisher","first-page":"557","DOI":"10.1016\/S0733-8627(20)30467-3","article-title":"Functional anatomy of the hand","volume":"11","author":"Belliappa","year":"1993","journal-title":"Emerg Med Clin North Am"},{"key":"B11","doi-asserted-by":"publisher","first-page":"107","DOI":"10.1016\/S0363-5023(78)80057-4","article-title":"Polydactyly of the thumb: abnormal anatomy and treatment","volume":"3","author":"Marks","year":"1978","journal-title":"J Hand Surg Am"},{"key":"B12","doi-asserted-by":"publisher","first-page":"e4009","DOI":"10.1097\/GOX.0000000000004009","article-title":"Detailed anatomy and reconstructive approach of a Wassel VI thumb duplication","volume":"10","author":"Kareh","year":"2022","journal-title":"Plast Reconstr Surg Glob Open"},{"key":"B13","doi-asserted-by":"publisher","first-page":"2113","DOI":"10.1007\/s00264-023-05858-y","article-title":"News in paediatric orthopaedic surgery: an overview of the latest advances in paediatric orthopaedics and traumatology (2020\u20132023)","volume":"47","author":"Mainard","year":"2023","journal-title":"Int Orthop"},{"key":"B14","doi-asserted-by":"publisher","first-page":"1536872","DOI":"10.3389\/fped.2025.1536872","article-title":"Radiographic features of Wu et al. Type A2 congenital thumb duplication and implications for management: new subtypes and surgical strategies","volume":"13","author":"Wu","year":"2025","journal-title":"Front Pediatr"},{"key":"B15","doi-asserted-by":"publisher","first-page":"669","DOI":"10.1177\/1753193410373686","article-title":"The oblique wedge osteotomy of the metacarpal condyle for reconstructing Wassel type IV thumb duplication in older children and adults","volume":"35","author":"Chew","year":"2010","journal-title":"J Hand Surg Eur"},{"key":"B16","doi-asserted-by":"publisher","first-page":"1220","DOI":"10.1097\/PRS.0000000000003877","article-title":"Oblique osteotomy for the correction of the Zigzag deformity of Wassel type IV polydactyly","volume":"140","author":"Kim","year":"2017","journal-title":"Plast Reconstr Surg"}],"container-title":["Frontiers in Pediatrics"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2026.1894739\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T05:55:37Z","timestamp":1786514137000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2026.1894739\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,12]]},"references-count":16,"alternative-id":["10.3389\/fped.2026.1894739"],"URL":"https:\/\/doi.org\/10.3389\/fped.2026.1894739","relation":{},"ISSN":["2296-2360"],"issn-type":[{"value":"2296-2360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,12]]},"article-number":"1894739"}}