Intraoperative Cultures in Reimplantation of a Two-Stage Protocol: Only 1 vs. At Least 2 Positive Microbiological Results



José Cordero-Ampuero1, 2, Ana Ortega-Columbrans1, Eduardo Garcia-Rey2, 3, Eduardo Garcia-Cimbrelo3, *
1 Department of Orthopaedic Surgery and Traumatology, University Hospital La Princesa, Madrid, Spain
2 Medicine School, Universidad Autónoma de Madrid, Spain
3 Department of Orthopaedic Surgery and Traumatology, University Hospital La Paz-IDIPaz, Madrid, Spain

Abstract

Background:

The main reason for using a two-stage exchange in prosthetic joint infection (PJI) is that bacteria are completely eradicated in reimplantation surgery. However, reports of a positive culture in the second surgery are growing. The number of positive intraoperative cultures and their influence on final results is not well-established.

Objectives:

To compare epidemiological characteristics, infection recurrence and clinical evolution of patients with only one vs. at least two positive cultures based on our series of cases with positive cultures in reimplantation surgery.

Material and Methods:

Retrospective study of 55 patients was conducted prospectively. They were diagnosed with chronic PJI, treated with a two-stage protocol and at least three intraoperative cultures were obtained in the second stage. These cultures were negative in 28 patients. Fourteen patients showed two or more cultures with the same microorganism and they were denominated patients with positive cultures. Thirteen patients showed only one positive culture, and they were considered contaminated. Both groups of patients (positive cultures and contaminated ones) received the second cycle of oral antibiotics for 6 months. Functional results were evaluated with the Harris Hip Score (hips) or Knee Society Clinical Rating Score (KSCRS) (knees).

Results:

There were no significant differences between patients with positive or contaminated cultures for age (p=0.420) and sex (p=0.385). The knee was involved in 13/14 positive and in only 6/13 contaminated patients (p=0.013). Staphylococcus epidermidis was the predominant isolate, but there were differences between positive (methicillin-resistant in 7/14 patients) and contaminated cultures (methicillin-sensitive in 6/13). There were no differences in the prevalence of polymicrobial cultures (p=0.785) or coincidence with cultures from the first stage (p=0.257). Three infection recurrences have appeared in patients with positive cultures (3/13, 21%) and none in patients with contaminated cultures. There are no differences in HSS or KSCRS when comparing final functional results between groups (p=0.411).

Conclusion:

The prevalence of positive cultures in reimplantation surgery is higher than expected (25%), and more frequent in women and in knee arthroplasties. The most frequently involved microorganism is Staphylococcus epidermidis, but antibiotic sensitivity varies between patients with positive cultures (methicillin-resistant) and those with contaminated cultures (methicillin-sensitive). There were no infection recurrences in patients with contaminated cultures, but those with positive cultures present a risk of over 20%.

Keywords: Prosthetic joint infection, Two-stage exchange arthroplasty, Reimplantation culture, Clinical evolution.


Abstract Information


Identifiers and Pagination:

Year: 2019
Volume: 13
Publisher Id: TOORTHJ-19052701

Article History:

Received Date: 23/12/2018
Revision Received Date: 25/03/2019
Acceptance Date: 20/05/2019
Electronic publication date: 29/05/2019
Collection year: 2019

© 2019 Cordero-Ampuero et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Correspondence: Address correspondence to this author at the Department of Orthopaedic Surgery and Traumatology, University Hospital La Paz-IDIPaz, Madrid, Spain; E-mail: gcimbrelo@yahoo.es