Frequently Asked Questions


Please complete the online or fax the completed Synovasure Physician Enrollment Form to CD Laboratories at 410-415-1951 (or email to [email protected]). Enrollments are typically processed within 72 hours of receipt. To order kits, contact you local Zimmer Biomet distributor or call Zimmer Biomet Customer Service at 800-348-2759 (Option 1)

Synovasure RISC® Panel testing is exclusively serviced by CD Laboratories (CLIA License# 21D0216863), a subsidiary of Zimmer Biomet, located in Baltimore, MD.

As part of the Synovasure RISC® Panel, synovial fluid biomarker tests are to performed to aid in a differentiating between common arthritis conditions:

  • Native Septic Arthritis (NSA)
  • Osteoarthritis (OA)
  • Rheumatoid Arthritis (RA)
  • Crystalline Arthritis

The Synovasure Arthritis Specimen Transportation kit contains the materials needed to send synovial fluid specimens to CD Laboratories:

  • Submission Instructions Sheet
  • 95 kPa Specimen Transport Biohazard Bag
  • Specimen Tubes (2 clear top, red stopper and 1 Lavender top)
  • Test Requisition Form
  • Biological Specimen Box
  • Prepaid FedEx Pouch for Biological Specimens
  • Prepaid FedEx shipping label
  • Patient record labels (x4)

*Note: Patient record labels are not to be used on tubes. These labels are for the placement on test requisition form and any internal records for patient within clinic to denote usage.

To order the Synovasure Arthritis Specimen Transportation Kit, contact your local Zimmer Biomet sales representative.

After the testing is completed, results are sent via a protected PDF email or fax, as noted as the preferred method by practice upon enrollment with CD Laboratories. 

Results are provided for all tests requested and are intended to be used in conjunction with other clinical and diagnostic findings to aid a patient’s diagnosis. For description of each test, refer to the reverse side of the Test Requisition Form, Results Report, or click here.

Test results are typically available within 3 business days of the receipt of specimen at CD Laboratories. To ensure quick turnaround, please ensure that the test requisition form is fully completed and tubes are labeled with patient name and date of birth. Failure to do so will result in specimen processing delays.

The physician’s office can track the shipment using the tracking number on the FedEx return label provided in the Synovasure® Arthritis Specimen Transportation Kit.

Specific instructions are provided on the Test Submission Instructions within each kit to ensure that specimens are picked up and delivered in a timely fashion. To schedule your “prepaid pickup”. Call 1-800-463-3339 (1-800-GOFEDEX) or schedule online through

Note: Packages CANNOT be placed in a FedEx dropbox.

If you aspirate a synovial fluid sample on Friday or over the weekend, please refrigerate the specimen and ship it on Monday. A sample can be refrigerated for up to 3 days.

Synovasure® Osteoarthritis (OA) Testing

As part of the Synovasure RISC® Panel, two biomarkers indicative of isolated, idiopathic OA are tested:

  • COMP
  • IL-8

Cartilage Oligomeric Matrix Protein (COMP) is a biomarker that has been found to be tied to cartilage breakdown. Elevated levels suggest presence of OA and cartilage degradation.1,2 Clinical studies have shown higher concentrations of COMP in synovial fluid than serum.2

Interleukin-8 (IL-8) is a biomarker that attracts and activates neutrophils in areas of inflammation. Elevated concentrations have been shown in cases of various forms of inflammatory arthritis.3,4 As a result, IL-8 aids in differentiating primary and secondary OA.

Since IL-8 is more prevalent in inflammatory arthritis, the ratio allows differentiating between patients with primary vs. secondary OA. As IL-8 increases, the ratio decreases signaling a higher likelihood that the symptoms are caused by an inflammatory condition with secondary OA.5

Synovasure® Rheumatoid Arthritis (RA) Testing

As part of the Synovasure RISC® Panel, two biomarkers indicative of RA are tested:

  • Anti-CCP
  • RF

Anti-Cyclic Citrullinated Peptide (Anti-CCP) is an antibody, commonly assessed via a blood test, produced by the body that identifies and attacks cells as if it were a foreign material. Elevated levels of anti-CCP have been thought to be present in 60-70% of patients with RA6. The Synovasure RA test evaluates levels of Anti-CCP in synovial fluid instead of blood.

Rheumatoid Factor (RF) is a protein, commonly tested via a blood test, produced by the immune system to attack healthy tissue. The biomarker indicates the presence of an autoimmune disease such as RA7. Synovasure RA testing evaluates RF in synovial fluid instead of blood.

Note: Other synovial fluid tests for RF do exist, but are not part of a comprehensive, differential diagnosis panel.

Synovasure® Crystalline Arthritis Testing

As part of the Synovasure RISC® Panel, two (2) types of crystals are tested – MSU and CPPD crystals – which are common in cases of gout and pseudogout/CPPD.

No. The same test is performed in both panels using the same high-powered microscopy at CD Laboratories.

Synovasure® Native Septic Arthritis (NSA) Testing

As part of the Synovasure RISC® Panel, white blood cell (WBC) count with differential is tested for NSA. If the total nucleated cell count is > 3,000 cells/uL or PMN% is > 70%, the specimen is also tested for:

  • Synovasure Alpha Defensin for NSA ( alpha defensin and lactate)
  • Synovasure Microbial Identification
  • Culture

Elevated WBC counts are the result of the presence of inflammation. If WBC count is elevated, the specimen is assessed for alpha defensin levels to aid in differentiating the cause of the elevated cell count between infection or other inflammatory conditions.


Upon completion of testing, CD Laboratories will handle billing for testing based on a patient’s insurance:

  • Medicare: CD Laboratories bills Medicare directly on behalf of the patient
  • Non-Medicare: CD Laboratories bills patient directly. In parallel a courtesy claim is placed on patient’s insurance. Any available reimbursement will be provided back to patient by their insurance provider.

For most patients CD Laboratories is an out-of-network provider as it is located in Maryland. The Synovasure laboratory testing is only available through CD Laboratories as it is proprietary to our laboratory, so testing cannot be performed at any other laboratory including LabCorp or Quest Diagnostics. For more information regarding our status as out-of-network, click here.

  1. Bellucci F., et al. Synovial Fluid Levels of Bradykinin Correlate with Biochemical Markers for Cartilage Degradation and Inflammation in Knee Osteoarthritis. Osteoarthritis and Cartilage. 21(11) 1774-1780, 2013.
  2. Arellano R., et al. Cartilage Oligomeric Matrix Protein Levels in Synovial Fluid in Patients with Primary Knee Osteoarthritis and Healthy Controls: A Preliminary Comparative Analysis with Serum Cartilage Oligomeric Matrix Protein. Archives of Rheumatology. 32(3):189-196, 2017.
  3. Partsch G., et al. Highly Increased Levels of Tumor Necrosis Factor-alpha and Other Proinflammatory Cytokines in Psoriatic Arthritis Synovial Fluid. The Journal of Rheumatology. 24(3) 518-523, 1997.
  4. Harada A., et al. Essential Involvement of Interleukin‐8 (IL‐8) in Acute Inflammation. Journal of Leukocyte Biology, 56(5) 559-564, 1994.
  5. 12514-009 – Technical Report: Performance of Synovasure® Differential Diagnosis Arthritis Panel Diagnostic Accuracy Test
  6. Freeman, J. RA and Anti-CCP: What is the Purpose of an Anti-CCP Test? Accessed 1 Apr 2020.
  7. Street, T. Rheumatoid Factor. Accessed 1 Apr 2020.