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ORIGINAL RESEARCH article

Front. Cell. Infect. Microbiol.

Sec. Clinical Microbiology

Volume 15 - 2025 | doi: 10.3389/fcimb.2025.1459205

This article is part of the Research Topic Pathogenic Mechanisms and New Technology-Based Diagnostics for Bacterial Infections View all 5 articles

Pin-tract Infection is an Important Factor Associated with Pin Loosening During External Fixation: A Prospective Analysis of 47 Consecutive Patients

Provisionally accepted
Yong-Yi Huang Yong-Yi Huang 1,2Chen-Sheng Song Chen-Sheng Song 1Yu Yao Yu Yao 1Yu-Sheng Yang Yu-Sheng Yang 1Liang-Jie Tian Liang-Jie Tian 1Qing-Rong Lin Qing-Rong Lin 1Ru-Hao Han Ru-Hao Han 1Hong-Wei Xi Hong-Wei Xi 1Bo-Wei Wang Bo-Wei Wang 1Nan Jiang Nan Jiang 1*Yanjun Hu Yanjun Hu 1*Yanjun Hu Yanjun Hu 1*
  • 1 Department of Orthopaedics& Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
  • 2 Department of Orthopaedics& Traumatology, Yunfu People's Hospital, Yunfu, Guangdong, China

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

    The occurrence of pin loosening represents a common issue in the context of external fixation methodologies; nevertheless, a comprehensive investigation into the multifaceted causes of pin loosening, incorporating a multivariate analysis among pin infection, bone quality, and pin insertion angle, is notably absent in current literature. The present study endeavors to pinpoint factors associated with pin loosening through such a multivariate analysis.The study encompassed patients who underwent the removal of external fixators from March 2023 to July 2023. The assessment of pin loosening was executed through the utilization of the pin track score, the pin removal torque value (PRTV), and the radiolucent zone around the pin (RZAP) as depicted in digital radiography (DR) images. Culturing of the pin-bone interfaces was performed, and measurements of the grayscale intensity of cortical bone (GSCB) and pin verticality within DR images were taken. Multivariate analyses were conducted employing a Generalized Linear Mixed-Effects Model (GLMM), Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated by exponentiating the model coefficients (Exp(β)).Results: Altogether 47 patients with a total of 220 pins were included for analysis. The mean PRTV was 1.9 ± 2.1 N• m. The correlation analysis between PRTV and RZAP yielded a P-value of less than 0.001, signifying a substantial correlation between pin loosening and RZAP. For pins with a PRTV of 0, the RZAP measured 1.9 ± 0.8 mm. The positive rate of bacterial culture was 20%, and the loosening rate was 26.8%. Pin loosening was significantly associated with bacterial infection (aOR = 2.24, 95% CI: 1.03-4.90, P = 0.04) and GSCB (aOR = 0.50, 95% CI: 0.38-0.66, P < 0.01), but not with pin verticality (aOR = 1.00, 95% CI: 0.93-1.08, P = 0.99). Non-HA-coated pins remained significantly associated with bacterial infection (aOR = 8.20, 95% CI: 2.18-30.85, P = 0.002), whereas HA-coated pins were not (aOR = 3.44, 95% CI: 0.24-48.76, P = 0.36).Pin loosening was significantly associated with bacterial infection at the pin-bone interface and lower GSCB, but not with pin verticality. Notably, infection strongly predicted loosening in non-HA-coated pins, while HA-coated pins demonstrated higher raw infection rates.

    Keywords: Pin loosening, Bacterial culture, Pin infection, bone quality, Insertion angle

    Received: 03 Jul 2024; Accepted: 06 Mar 2025.

    Copyright: © 2025 Huang, Song, Yao, Yang, Tian, Lin, Han, Xi, Wang, Jiang, Hu and Hu. 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:
    Nan Jiang, Department of Orthopaedics& Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
    Yanjun Hu, Department of Orthopaedics& Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
    Yanjun Hu, Department of Orthopaedics& Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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