The first and only laboratory test designed and developed to aid in the diagnosis of PJI, the Synovasure Alpha Defensin ELISA Test assesses levels of alpha defensin, an antimicrobial peptide released by neutrophils in response to a pathogen in synovial fluid.

Highly Accurate for PJI Diagnosis  ⁴

• 94.9% Sensitivity
• 97.4% Specificity

Performance Unaffected by:

• Prior antibiotic administration ^5,6
• Comorbidities related to inflammation ^{5, 7}
• Type/Virulence of organism ^{5, 8}

The Synovasure Microbial Identification test utilizes a novel bead-based method for 24-hour detection of microbial antigens in synovial fluid.

Validated for Common Species

Designed to detect microorganisms responsible for more than 70% of PJI⁷ including: 

• Staphylococcus species
• Enterococcus species
• Candida species
• Cutibacterium acnes (formerly P. acnes)

Performance backed by Data

• Demonstrated >94% overall panel sensitivity for the detection of microorganism species in infected synovial fluid samples ^{9, 10}
• Demonstrated >98% overall panel specificity in non-infected synovial fluid samples ^9,10
• According to a 2023 study, the MID Panel detected presence of a microorganism in ~50% of culture-negative PJI ¹⁰

*Synovasure Microbial Identification is not available in New York State

Approximately 8% of synovial fluid specimens are affected by quality including dilution and blood contamination.¹¹ As part of the panel, every specimen is tested for integrity prior to result reporting.

Specimen integrity test assesses:

• Absorbance at 280 nm (A280) – Identifies if specimen has been diluted via lavage or use of contrast agents
• Red Blood Cell Count – Verifies that specimen is characteristic of synovial fluid, not blood

White Blood Cell (WBC) Count w/ Differential

Automated, high-performance cell count that provides overall number of white blood cells and percentage breakdown of white blood cell (WBC) type in synovial fluid.

A 2020 study showed that automated WBC count can be affected by the presence of a total joint arthroplasty, leading to higher rates of false-positive results.¹² All WBC counts >3,000 cells/ul are confirmed by a manual count.

Synovial Fluid C-Reactive Protein (CRP)

The Synovial Fluid CRP test measures the levels of the c-reactive protein biomarker within a specimen.

A 2024 clinical study demonstrated 86.1% sensitivity and 87.1% specificity compared to the 2018 ICM Definition of PJI, outperforming published serum CRP diagnostic performance.¹³

Synovial Fluid Culture

Aerobic and anaerobic culture to determine identity and susceptibility of organisms. Cultures are held for seven (7) days on all samples and 14 days for shoulder specimens. Culture is performed along the Synovasure Comprehensive PJI Test Panel but is not included as part of the SynTuition score.

Crystal Analysis

Polarized microscopy to detect monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystals to aid in identifying the presence of gout and CPPD disease (pseudogout).

The Synovasure Comprehensive NSA Panel offers similar tests to the Synovasure Comprehensive PJI panel that are fine-tuned for the nuances associated with a native joint through the inclusion of lactate testing as part of Synovasure Alpha Defensin ELISA and crystal analysis testing.