Evidence map›Paper›PMID 42299374›Full record

ArticleJB & JS open access

Marked Increase in Anterior Ulnar Nerve Displacement at ≥90° of Elbow Flexion in Healthy Children.

Tomoo Nakagawa, Youichi Yasui, Kenichi Kawabata, Jun Sasahara, Takahiro Inui, Masashi Nei, Yoichiro Konno, Hirotaka Kawano, Wataru Miyamoto

Abstract read
In one paragraph

Article in JB & JS open access. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Tomoo NakagawaDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0002-1122-7556
Youichi YasuiDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0002-9866-503X
Kenichi KawabataDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0009-0004-7328-0637
Jun SasaharaDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0003-4192-4085
Takahiro InuiDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0003-4733-5281
Masashi NeiDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0002-5419-2365
Yoichiro KonnoDepartment of Rehabilitation, Teikyo University Hospital, Tokyo, Japan.ORCID https://orcid.org/0009-0009-6780-0153
Hirotaka KawanoDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0003-3156-5904
Wataru MiyamotoDepartment of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.ORCID https://orcid.org/0000-0002-9038-8840

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Iatrogenic ulnar nerve (UN) injury is a serious complication of percutaneous medial pinning for pediatric supracondylar humeral fractures, particularly when deep elbow flexion is required for reduction. However, the flexion angle at which the nerve becomes unstable and patient characteristics predisposing to displacement remain unclear. This study aimed to determine the elbow flexion angle at which UN instability occurs in healthy children and to identify independent risk factors for anterior displacement. Methods: A cross-sectional study of 74 healthy, asymptomatic children (144 elbows) aged 7 to 12 years was conducted. Dynamic ultrasonography was performed at 5 static flexion angles (0°, 30°, 60°, 90°, and 120°), with nerve position classified as normal, subluxated, or dislocated relative to the medial epicondyle. Multivariate logistic regression analysis identified independent predictors of instability (subluxation or dislocation) at deep flexion (≥90°), evaluating age, sex, body mass index, handedness, and generalized joint laxity. Results: UN instability increased progressively with elbow flexion. At 0° and 30°, the nerve remained stable in >97% of elbows. A marked increase in instability was observed at ≥90°: 60.4% demonstrated instability (50.0% subluxation, 10.4% dislocation) at 90°, rising to 94.4% (54.2% subluxation, 40.3% dislocation) at 120°. Multivariate analysis identified female sex (odds ratio 3.61; 95% confidence interval 1.50-8.67) and generalized joint laxity (odds ratio 2.61; 95% confidence interval, 1.03-6.61) as independent risk factors. Age, body mass index, and handedness were not significantly associated with displacement. Conclusions: In healthy children, the UN demonstrated a pronounced angle-dependent pattern, with marked anterior displacement at ≥90° of flexion. Female sex and generalized joint laxity were associated with higher odds of sonographic instability. These findings characterize the anatomical behavior of the UN during elbow flexion and provide context for future investigation in surgical populations. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence.

Identifiers

PMID42299374
PMCPMC13259555

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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.