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ORIGINAL RESEARCH article

Front. Pediatr.
Sec. Pediatric Orthopedics
Volume 13 - 2025 | doi: 10.3389/fped.2025.1536872

Radiographic features of Wu et al. type A2 congenital thumb duplication and implications for management: new subtypes and surgical strategies

Provisionally accepted
Jianping Wu Jianping Wu 1*Shijie Liao Shijie Liao 2Yuquan Li Yuquan Li 3*Fulong Xu Fulong Xu 1*Hai Zhao Hai Zhao 4*Chenyang Li Chenyang Li 2*Yanhan Liu Yanhan Liu 1*Xinwang Zhi Xinwang Zhi 1Honghong Lin Honghong Lin 1*Zhehui Tu Zhehui Tu 1*Lili Shu Lili Shu 1*Jingchun Li Jingchun Li 1YiQiang Li YiQiang Li 1Federico Canavese Federico Canavese 5HongWen Xu HongWen Xu 1*YuanZhong Liu YuanZhong Liu 1*
  • 1 Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
  • 2 First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi Zhuang Region, China
  • 3 Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Region, China
  • 4 The First People's Hospital of Chenzhou, Chenzhou, Hunan Province, China
  • 5 Giannina Gaslini Institute (IRCCS), Genoa, Liguria, Italy

The final, formatted version of the article will be published soon.

    This study aimed to assess the radiographic features of patients diagnosed with congenital thumb duplication (CTD) type A2 based on the Wu et al. classification, describe the different subtypes of duplications and propose a classification system that permits identifying various surgical strategies.We evaluated 665 patients (680 thumbs) diagnosed with type A2 CTDs by examining the alignment of the interphalangeal (IP) and metacarpophalangeal (MP) joints of the primary thumb on posteroanterior (PA) radiographs. The classification system has four types: Type I (no deviation); Type II (ulnar deviation); Type III (hypertrophic epiphysis); and Type IV (convergent). Types I-IV were compared to Hung et al.'s system Type A-D (Hypoplastic, Ulnar Deviation, Divergent, and Convergent).Of the 680 fingers, 436 (64.1%) were determined to be Wassel type IV while 244 (35.9%) were classified as Wassel type VII. All of the 436 fingers could be categorized according to the subtypes of the Hung et al. system; in particular, 369 (84.6%) were identified as type B, 52 (11.9%) as type D, and 15 cases (3.4%) as type C. The proposed classification system worked effectively for all CTDs (n=680). 494 cases were classified as type II (72.6%), while 75 cases were classified as type I (11.0%). The remaining 111 cases were further classified as either type IV (9.3%) or type III (7.1%). The Wu et al. systems showed excellent intra-rater (0.881) and interrater (0.873) reliability compared to the Hung et al. systems (0.842 and 0.823, respectively).The proposed radiographic pathoanatomical system has the potential to improve communication and guide optimal procedure selection for different subtypes of CTD depending on the attachment of the extra digit to the main thumb and the alignment of the interphalangeal and metacarpophalangeal joints of the primary thumb (Wu et al.

    Keywords: congenital thumb duplication, Wu et al. classification, Anatomy, interphalangeal and metacarpophalangeal joint alignment, Surgery

    Received: 20 Dec 2024; Accepted: 03 Feb 2025.

    Copyright: © 2025 Wu, Liao, Li, Xu, Zhao, Li, Liu, Zhi, Lin, Tu, Shu, Li, Li, Canavese, Xu and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Jianping Wu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    Yuquan Li, Second Affiliated Hospital of Guangxi Medical University, Nanning, 530007, Guangxi Zhuang Region, China
    Fulong Xu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    Hai Zhao, The First People's Hospital of Chenzhou, Chenzhou, Hunan Province, China
    Chenyang Li, First Affiliated Hospital, Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Region, China
    Yanhan Liu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    Honghong Lin, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    Zhehui Tu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    Lili Shu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    HongWen Xu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
    YuanZhong Liu, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China

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