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J Wrist Surg
DOI: 10.1055/a-2772-1602
Scientific Article

The Impact of Capitate Morphology on Scaphoid Flexion in Wrist Kinematics

Authors

  • Cheng-En Hsu

    1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    2   Division of Plastic Surgery, Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States
    3   Department of Orthopaedics, Taichung Veterans General Hospital, Taichung, Taiwan
    4   Sports Recreation and Health Management Continuing Studies-Bachelor's Degree Completion Program, College of Agriculture, Tunghai University, Taichung, Taiwan

  • Parunyu Vilai

    1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    5   Department of Orthopedic Surgery, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand

  • Rou Wan

    1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, United States

  • Chunfeng Zhao

    1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, United States

  • Steven L. Moran

    2   Division of Plastic Surgery, Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States
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Abstract

Background

Column-type wrists, which exhibit increased scaphoid flexion during radial deviation, often experience greater loss of motion after periscaphoid arthrodesis compared with row-type wrists. Dynamic radiographic series are typically used to differentiate these kinematic patterns. In this study, we evaluate capitate morphology as a means of predicting column- or row-type carpal kinematics.

Materials and Methods

This study investigated whether wrist kinematic patterns could be predicted using simple anteroposterior (AP) radiographs. We hypothesized that capitate morphology, given its close articulation with the scaphoid, influences these patterns. We analyzed 75 wrist motion radiographic series from 45 patients. Capitates were classified as either Type I (rectangular) or Type II (pentagonal) based on their shape. Wrist kinematic patterns were categorized as row- or column-type based on the degree of scaphoid length shortening during radial deviation.

Results

Our analysis revealed that a Type II capitate was a significant predictor of column-type wrists, with an odds ratio of 6.01 compared with Type I (p = 0.014). Furthermore, Type II capitates were associated with increased scaphoid flexion and reduced translation.

Conclusion

Capitate morphology, as assessed from a plain AP radiograph, can serve as an easily accessible marker and reliable predictor of wrist motion patterns. This could potentially aid in surgical planning and patient counseling, particularly when dynamic radiographic series are not feasible.

Study Type/Level of Evidence:

Diagnostic, Level III.

Keywords

capitate - morphology - scaphoid kinematics - radial–ulnar deviation - wrist motion - radiographs - wrist kinematics

Contributors' Statement

Cheng-En Hsu: conceptualization, study design, experiment (surgery), data collection and formal analysis, data interpretation, manuscript drafting, manuscript editing, manuscript finalizing, and approval. Parunyu Vilai and Rou Wan: data collection and interpretation, manuscript finalizing and approval. Chunfeng Zhao: resources, data interpretation, manuscript editing, manuscript finalization. Steven L. Moran: resources, conceptualization, study design, data interpretation, manuscript editing, manuscript finalizing and approval. Artificial intelligence has been employed for the detection of typos and the polishing of English language.


Ethical Approval

Approval from the institutional review board was obtained for this retrospective study. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.




Publication History

Received: 22 July 2025

Accepted: 12 December 2025

Article published online:
06 January 2026

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