Abstract
Introduction
Recent focus has shifted towards the utilization of deoxyribonucleic acid (DNA) sequencing modalities in periprosthetic joint infection (PJI) diagnosis and organism identification. The purpose of this study was to compare the diagnostic accuracy of next generation sequencing (NGS) to polymerase chain reaction (PCR) multiplex, culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al. [1] in the diagnosis of periprosthetic hip infections.
Methods
In this retrospective study, aspirate or tissue samples were collected in 23 revision and 19 primary hip arthroplasties for routine diagnostic workup for PJI and sent to the laboratory for NGS and PCR multiplex. Concordance along with statistical differences between diagnostic studies were calculated using Chi-squared test for categorical data.
Results
When comparing to the MSIS criteria, concordance was 71.4% for NGS, 64.3% for PCR, and 92.9% for culture (p<0.001). There was no significant difference based on prior infection (p=0.695), or sample collection method (tissue swab or synovial fluid) (p=0.327). Seven samples were culture positive and NGS negative all of which met both criteria for PJI. Four patients were culture negative but NGS positive, of which 1 (25.0%) met both criteria. Concordance was 100% between the MSIS criteria and criteria proposed by Parvizi et al. [1].
Conclusion
In this initial cohort NGS was more accurate than 16s subunit PCR techniques, but less accurate than culture in the diagnosis of PJI determining the presence or absence of PJI. What is not clear is how NGS will perform against culture in terms of identifying the specific bacterial strain. Currently, laboratory tests used for either criteria for PJI diagnosis should be obtained regardless of NGS along with the overall clinical picture to help guide decision making for PJI treatment.
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