Abstract
Aim
In two-stage replacements for septic loosening, some studies have suggested that associate bacterial colonization of spacers had a worse result in relation to the control of the infection and a higher rate of complications after the implantation of the definitive prosthesis.
The aim of our study was to determine the reoperation rate of patients undergoing two-stage revision surgery according to the results of spacer sonication.
Method
A retrospective observational study was conducted in which 56 hip or knee spacers implanted at our center from 2010 to 2017 were analysed. Patients were grouped into three categories:
Patients with positive spacer sonication fluid culture, with or without positive cultures from the rest of the samples.
Patients with negative spacer sonication culture and negative second-stage intraoperative cultures.
Patients with negative spacer sonication culture but positive cultures of the rest of intraoperative samples.
Results
Of the 56 patients analysed, 11 were included in group A, 32 in group B and 13 in group C. The reoperation rate was 36%, 34% and 54% respectively. Reoperation rate due to infection was 9%, 25% and 46% respectively. In only two cases (both in group C), the reoperation was caused by infection by a previously isolated microorganism.
Spacers were colonized in all cases by low virulence microorganisms (coagulase negative staphylococci, P. acnes or Candida). Within group A, six patients also had other positive cultures.
Conclusions
In our study, bacterial colonization of the spacer is not associated with a higher rate of reoperations in the short-medium term. The group of patients with positive cultures in the second stage surgery was the one with the highest rate of reoperations.
