Summary:
This article provides an overview of orthopedic infections, their impact, and the need for accurate diagnosis to guide appropriate treatment. Methods of diagnosis discussed are as follows:
1. MICROBIOLOGICAL DIAGNOSIS: This section discusses the challenges in microbiological diagnosis, including the limitations of culture-based techniques, the importance of optimal sampling techniques, and the role of swabs, Gram stain, and fungal/mycobacterial cultures. It also highlights the need to distinguish contaminants from true pathogens in prosthetic joint infections.
2. PATHOGEN DETECTION: This section focuses on optimizing culture-based techniques for pathogen detection in bone and joint infections. It emphasizes the importance of obtaining samples with minimal contamination, using aseptic technique, and obtaining multiple samples for accurate diagnosis. It also discusses the use of blood culture bottles for synovial fluid and periprosthetic tissue samples and the duration of bacterial culture incubation.
3. MOLECULAR TECHNIQUES: The section explores the use of PCR and molecular techniques in the diagnosis of bone and joint infections. It discusses the two approaches of PCR: targeting specific organisms or using broad-range 16S PCR followed by sequencing. The advantages and limitations of PCR are highlighted, along with the role of shotgun metagenomics in pathogen identification.
4. DETECTION OF HOST RESPONSE: This section focuses on detecting the host response in orthopedic infections. It discusses the use of serum biomarkers, such as ESR, CRP, IL-6, and procalcitonin, and their limitations. Synovial fluid analysis is explored, including white cell count, biomarkers like leukocyte esterase and alpha defensin, and the role of histology and radiological imaging, such as plain films, CT, MRI, and nuclear imaging.