Evidence map›Paper›PMID 41117140›Full record

ArticleThe Journal of hand surgery, European volume2026

Anatomical study of the radial side of thumb metacarpophalangeal joint: the joint capsule and flexor pollicis brevis muscle.

Jun Hishiyama, Akimoto Nimura, Satoru Muro, Hitomi Fujishiro, Toshitaka Yoshii, Keiichi Akita

Abstract read
In one paragraph

Article in The Journal of hand surgery, European volume, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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0cells of the map it votes in
1citing papers in PubMed
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1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

6 authors.

Jun HishiyamaDepartment of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan.ORCID 0009-0006-2578-6830
Akimoto NimuraDepartment of Functional Joint Anatomy, Biomedical Engineering Laboratory, Institute of Industry Incubation, Institute of Science Tokyo, Tokyo, Japan.ORCID 0000-0002-3054-0273
Satoru MuroDepartment of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan.ORCID 0000-0002-4709-6359
Hitomi FujishiroDepartment of Anatomy and Physiological Science, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan.ORCID 0000-0001-5025-8331
Toshitaka YoshiiDepartment of Orthopedic and Spinal Surgery, Graduate School of Medical and Dental Science, Institute of Science Tokyo, Tokyo, Japan.ORCID 0000-0003-3511-9020
Keiichi AkitaDepartment of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan.ORCID 0000-0002-2927-2937

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionRadial collateral ligament reconstruction for thumb metacarpophalangeal joint instability can result in residual pain and limited motion. While the flexor pollicis brevis, located on the radial side of the metacarpophalangeal joint, is believed to contribute to dynamic stability, the radial collateral ligament provides static stability. However, the structural relationship between the flexor pollicis brevis, radial collateral ligament and joint capsule remains unclear. This study aimed to clarify the anatomical and functional relationship between flexor pollicis brevis, radial collateral ligament and joint capsule of the thumb metacarpophalangeal joint, and to validate these findings using in vivo imaging.

methodsEighteen cadaveric thumbs were examined using micro-computed tomography (micro-CT), macroscopic dissection, and histological analysis. Axial CT images were reconstructed to assess cortical bone thickness. Ultrasonographic imaging was performed on 10 thumbs from healthy volunteers to verify the anatomical findings.

resultsMacroscopic analysis showed that the flexor pollicis brevis intramuscular aponeurosis merges with the joint capsule to form a 'capsuloaponeurotic membrane' that incorporates the radial collateral ligament. Histology confirmed this structural integration. Cortical bone was thickened at the radial collateral ligament attachment sites, consistent with mechanical loading. Ultrasonography demonstrated continuity between the flexor pollicis brevis aponeurosis and the joint capsule in living subjects, supporting cadaveric findings.

conclusionThe flexor pollicis brevis muscle contributes to dynamic stabilization of the thumb metacarpophalangeal joint via its aponeurosis, which integrates with the joint capsule and radial collateral ligament. These findings provide new insight into metacarpophalangeal joint stability and may improve surgical and rehabilitative approaches for radial-sided thumb instability.

Indexed as

Collateral LigamentsJoint CapsuleMetacarpophalangeal JointMuscle, SkeletalThumbAgedCadaverFemaleHumansMaleMiddle AgedUltrasonographyX-Ray MicrotomographyCollateral ligamenthyperextension deformityjoint capsulejoint instabilityjoint stabilitymetacarpophalangeal jointthumbtrapeziometacarpal jointultrasonography

Identifiers

PMID41117140
PMCPMC12946208

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.