Zimmer’s Periprosthetic Joint Infection Test Available in Europe

The first and only test specifically designed for the diagnosis of periprosthetic joint infection (PJI), is now eligible for sale in several European countries.

On November 19, 2014, Zimmer Holdings, Inc. announced its Synovasure Alpha Defensin test for PJI received Certificate of CE (IVD) Notification and European Authorized Representative (EAR) certificate. According to the company, with both certificates in place, Zimmer, in conjunction with its manufacturing partner CD Diagnostics, is now cleared to launch the test to an initial Tier 1 group of countries, including Germany, Italy, Netherlands, Spain, Switzerland and the UK.

Periprosthetic Joint Infection

According to a June 2010 Guidelines and Evidence Report approved by the Board of Directors of the American Academy of Orthopaedic Surgeons (AAOS), PJI can be caused by “entry of organisms into the wound during surgery, hematogenous spread, recurrence of sepsis in a previously infected joint, or contiguous spread of infection from a local source.”

The incidence of PJI after primary hip or knee arthroplasty is over 2% among the Medicare population and is higher after revision arthroplasty than after primary arthroplasty in both joints.

AAOS says PJI requires significant resources to diagnose and treat. Infection is a common cause of revision arthroplasty, with 15% of revision total hip arthroplasties and 25% of revision total knee arthroplasties being due to infection.

Zimmer: “Unparalleled Accuracy”

Matt Monaghan, Zimmer’s senior vice president of Global Hips and Reconstructive Research, says the product already delivers “unparalleled accuracy, performance and ease of use in the U.S., and we are very excited to make the same technology available to doctors and patients in Europe. By being able to accurately determine PJI within 10 minutes, the Synovasure PJI Test brings a new level of diagnostics to the European market.”

The “Unparalleled Accuracy” of the test, includes:

• Achieving 97% sensitivity and 96% specificity by measuring synovial fluid alpha defensing.
• Alpha defensin is an antimicrobial peptide released by neutrophils in response to pathogens.
• Alpha defensin is an ideal biomarker for PJI due to the tremendous separation it achieves between positives and negatives.

Additionally, in performance results backed by data in a 158 patient study, the test maintained its performance in typically challenging situations such as:

• Culture Negative Infection — where 14 of 38 patients with PJI were culture negative and the test correctly identified all 14 as infected.
• Systemic Inflammatory Conditions — test studies included patients with systemic inflammatory disease and its performance was maintained in this population.
• Antibiotic Therapy — where 27% of patients with PJI had been treated with antibiotics prior to aspiration and the Synovasure PJI was not adversely affected in this population.

AAOS Guidelines

The AAOS Guidelines and Evidence Report recommends erythrocyte sedimentation rate and C-reactive protein testing for patients assessed for periprosthetic joint infection. You can read the guidelines here.