Differentiating between septic arthritis and other causes of joint inflammation in pediatric patients is challenging and of the utmost importance because septic arthritis requires surgical debridement as part of the treatment regimen. The current gold standard to diagnose septic arthritis in children is a positive synovial fluid culture; however, joint cultures may take several days to return. If a bacterial infection is present, it requires immediate surgical intervention in order to prevent lasting articular cartilage damage. Frequently surgeons must decide whether to surgically debride a joint before culture results are available. There is no single lab test or clinical feature that reliably indicates bacterial infection over other causes of joint inflammation. The alpha-defensin assay has shown high sensitivity and specificity for joint infection in other studies.The purpose of this study is to determine the sensitivity and specificity of several synovial biomarkers for diagnosing pediatric septic arthritis.
Synovial fluid is obtained to assess for infection or inflammatory/rheumatologic disease (all medium and large joints will be included: hip, knee, ankle, shoulder, subtalar, elbow, and wrist joints)
Patients with recent antibiotic exposure are eligible to participate but will be analyzed separately
Patients undergoing a procedure unrelated to infection (the procedure may be arthroscopy, or an open or percutaneous bony or soft tissue procedure)
Family declines to participate/consent
Patients with a major joint trauma (such as a documented ligament tear or fracture) within the past 8 weeks are not eligible to have that joint aspirated, but could have another joint aspirated
A history of recent infection (within the past 3 months)
Received antibiotics in the past 7 days
Parallel
Synovial Alpha-defensin assay
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial Neutrophil elastase assay
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial lactate assay
Diagnostic testSynovial Fluid (joint fluid) will be sent out to CD Diagnostics for this test.
Synovial C-reactive Protein (CRP)
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial Staphylococcus spp antigen panel
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial Candida spp antigen panel
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial Enterococcus faecalis assay
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial bacterial culture by BacT/Alert
Diagnostic testThe synovial fluid (joint fluid) sent to CD Diagnostics for testing will also be cultured to see if any organisms grow.
Synovial Cell count + differential (CBC)
Diagnostic testOne of the synovial fluid (joint fluid) tests that will be performed by the outside lab, CD Diagnostics.
Synovial Gram Stain
Diagnostic testThis will be performed by CD Diagnostics if any organisms are present in the synovial fluid.
Synovial Leukocyte Esterase Test Strips
Diagnostic testThese test strips will be tested at the hospital where the patient is being seen, a few drops of synovial fluid will be used on the strip.
Synovial PCR for Kingella kingae
Diagnostic testIn participants \< 8 years old, a sample of synovial fluid will be tested for Kingella kingae using PCR.
Serum Cell count + differential (CBC)
Diagnostic testA blood test performed at the hospital.
Serum erythrocyte sedimentation rate (ESR)
Diagnostic testA blood test performed at the hospital.
Serum C-reactive Protein (CRP)
Diagnostic testA blood test performed at the hospital.
Serum D-dimer
Diagnostic testA blood test performed at the hospital.
Serum Procalcitonin
Diagnostic testA blood test performed at the hospital.
Blood Cultures
Diagnostic testBlood will be cultured at the hospital to see if any organisms grow.
Optional blood testing per standard of care (ASO, anti-strep, ANA, anti-DS-DNA, HLA-B27, RF, Lyme and other inflammatory/ rheumatologic markers )
Diagnostic testIn patients with suspected inflammation/infection, there are other blood tests which may be standard of care and used for diagnosis.
Sensitivity and specificity of experimental tests
Sensitivity and specificity have been selected as these are standard outcome tests when determining the utility of a diagnostic test.
Click on the lead sponsor to view all of their trials.
Hospital for Special Surgery, New York
Lead sponsor
Pediatric Orthopaedic Society of North America
Collaborator
Children's Healthcare of Atlanta
Collaborator
Campbell Clinic
Collaborator
CD Diagnostics
Collaborator
