D-dimer, along with CRP, became a household name during Covid-19, a disease characterized by hyperinflammation and cytokine storm, as measures to assess disease severity. Elevated d-dimers are a marker for hypercoagulability and correlate with inflammation.

A new study published online Feb. 9, 2023 in the Journal of Bone and Joint Surgery (American volume) has suggested measurement of d-dimer as a useful test with "comparable diagnostic accuracy" as other commonly used biomarkers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)t o diagnose periprosthetic joint infections following knee and hip replacement surgeries.¹

Tarabichi and colleagues conducted this prospective study to find out if plasma d-dimer could aid diagnosis of periprosthetic joint infections in patients who underwent revision hip or knee replacement surgery (arthroplasty) for any surgical indication. ESR, CRP, plasma D-dimer and fibrinogen were measured in all patients just prior to the surgery. The diagnostic accuracy of d-dimer was compared with each biomarker.

Ninety-five (23.1%) of the 412 patients included in the study were found to have PJI, while 317 (76.9%) did not.

All the four markers were found to have comparable accuracy in diagnosing PJI. The sensitivity (true positives) for d-dimer in detecting PJI was 81.3%; it was 90.4% for CRP; 73.9% for ESR and 74.7% for fibrinogen. Whereas, the specificity (true negatives) was 81.7% for d-dimer, 70.0% for CRP, 85.2% for ESR and 75.4% for fibrinogen. D-dimer had the highest sensitivity (~94%) amongst all markers in detecting infection caused by indolent or slow growing microorganisms.

The diagnostic accuracy of all four biomarkers in detecting PJI was superior in patients who underwent knee arthroplasty compared to hip arthroplasty patients.

Periprosthetic joint infections are a dreaded complication of joint replacement surgery and a common cause of implant failure. It is not an easy condition to diagnose. This study compared the diagnostic usefulness of d-dimer in detecting PJI with ESR and CRP, the commonly used inflammatory markers and showed that the diagnostic performance of d-dimer was equivalent to ESR and CRP. The authors therefore suggest d-dimer as “a useful adjunct when screening patients undergoing revision total joint arthroplasty”. They also suggest further studies to establish “universal diagnostic cut-off points”.

Reference

1. Tarabichi S, et al. Plasma D-dimer is noninferior to serum C-reactive protein in the diagnosis of periprosthetic joint infection. J Bone Joint Surg Am. 2023 Feb 9. doi: 10.2106/JBJS.22.00784.