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CC BY 4.0 · Rev Bras Ortop (Sao Paulo) 2025; 60(02): s00451809337
DOI: 10.1055/s-0045-1809337
Original Article

Analysis of Microbiological Findings on the Surface of External Fixator Pins Comparing Steel Pins with Hydroxyapatite-Coated Pins

Análise dos achados microbiológicos identificados na superfície dos pinos de fixadores externos comparando pinos de aço com pinos revestidos por hidroxiapatita
Cristhopher Stoffel 
1   Instituto de Ortopedia e Traumatologia, Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil
,
Honório Octávio Cuadro Peixoto 
1   Instituto de Ortopedia e Traumatologia, Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil
,
Felipe Kowaleski dos Santos 
1   Instituto de Ortopedia e Traumatologia, Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil
,
Pedro Afonso Keller Licks 
1   Instituto de Ortopedia e Traumatologia, Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil
,
Fernando Baldy dos Reis 
2   Department of Orthopedics and Traumatology, Escola Paulista de Medicina, Universidade Federal de São Paulo, SP, Brazil
,
Mauro José Costa Salles 
3   Infectious Disease Discipline, Musculoskeletal Infection Group, Escola Paulista de Medicina, Universidade Federal de São Paulo, SP, Brazil
› Author Affiliations
Financial Support The authors declare that they did not receive financial support from agencies in the public, private, or non-profit sectors to conduct the present study.
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Abstract

Objective

To compare the microbial retrieval rates and the organism types on the surface of stainless-steel pins (SSPs) and hydroxyapatite-coated pins (HCPs) from external fixators (EFs).

Methods

The present prospective, non-randomized, multicenter, comparative interventional cohort study occurred from April 2018 to October 2021. The sample consisted of 44 patients with EFs, including 33 with SSPs and 11 with HCPs. We collected two pins from each patient, the one with the best and the one with the worst clinical appearance according to the Maz-Oxford-Nuffield (MON) classification, in an aseptic manner, and sent them for microbiological analysis.

Results

The overall superficial infection (SI) rate was 52.3% (23 of 44 patients), affecting 45.5% (5 of 11) patients with HCPs and 54.5% (18 of 33) patients with SSPs (p = 0.732). Of the 88 pins, 43.2% (38 of 88 pins) yielded microbial identification, with 42 pathogens isolated. Staphylococcus aureus was the most frequent organism, accounting for 59.5% (25 of 42 pathogens) of the positive samples. In the best-looking pins, the microbial retrieval rate was significantly lower in HCPs than SSPs, with 18.2% (2 pathogens in 11 pins) and 45.5% (15 pathogens in 33 pins), respectively (p = 0.036). In the worst-looking pins, the microbial retrieval rate in HCPs and SSPs was 27.3% (3 pathogens in 11 pins) and 54.5% (18 pathogens in 33 pins), respectively (p = 0.036).

Conclusion

Microbial retrieval rates were lower in HCPs than in SSPs. However, these differences did not impact clinical infection rates, which were similar in both groups.

Resumo

Objetivo

Comparar as taxas de recuperação microbiana e os tipos de microrganismos identificados na superfície dos pinos de aço inoxidável (PAIs) e nos pinos revestidos com hidroxiapatita (PHAs) de fixadores externos (FEs).

Métodos

Este estudo de coorte prospectiva de intervenção, não randomizado, multicêntrico, comparativo foi realizado entre abril de 2018 e outubro de 2021, com 44 pacientes tratados com FE, 33 dos quais receberam PAIs e 11 receberam PHAs. Foram coletados e enviados para análise microbiológica dois pinos de cada paciente, o de melhor e o de pior aspecto clínico conforme a classificação de Maz-Oxford-Nuffield (MON), de forma asséptica.

Resultados

A taxa de infecção (TI) superficial global foi de 52,3% (23 de 44 pacientes), sendo 45,5% (5 de 11 pacientes) entre pacientes que receberam PHAs e 54,5% (18 de 33 pacientes) entre pacientes que receberam PAI, respectivamente (p = 0,732). Dos 88 pinos, 43,2% (38 de 88 pinos) apresentaram identificação microbiana, sendo isolados 42 patógenos no total. O Staphylococcus aureus foi o mais frequente, representando 59,5% (25 dos 42 patógenos). Nas amostras de “melhor aspecto,” a taxa de recuperação microbiana foi significativamente menor nos PHAs do que nos PAIs, 18,2% (2 patógenos em 11 pinos) e 45,5% (15 patógenos em 33 pinos), respectivamente (p = 0,036). Nas amostras de “pior aspecto,” a taxa de recuperação microbiana nos PHAs e nos PAIs foi 27,3% (3 patógenos em 11 pinos) e 54,5% (18 patógenos em 33 pinos), respectivamente (p = 0,036).

Conclusão

As taxas de recuperação microbiana foram menores nos PHA comparadas às dos PAI. Entretanto, estas diferenças não impactaram nas taxas de infecção clínica, que foram semelhantes nos dois grupos.

Keywords

bone nails - bone wires - external fixators - hydroxyapatite - infections

Palavras-chave

fios ortopédicos - fixadores externos - hidroxiapatita - infecções - pinos ortopédicos

Work carried out at the Instituto de Ortopedia e Traumatologia, Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil.




Publication History

Received: 17 August 2024

Accepted: 07 March 2025

Article published online:
23 June 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/)

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Bibliographical Record
Cristhopher Stoffel, Honório Octávio Cuadro Peixoto, Felipe Kowaleski dos Santos, Pedro Afonso Keller Licks, Fernando Baldy dos Reis, Mauro José Costa Salles. Analysis of Microbiological Findings on the Surface of External Fixator Pins Comparing Steel Pins with Hydroxyapatite-Coated Pins. Rev Bras Ortop (Sao Paulo) 2025; 60: s00451809337.
DOI: 10.1055/s-0045-1809337