Serum D-dimer as a diagnostic index of PJI and retrospective analysis of etiology in patients with PJI

Objectives: To investigate the diagnostic value of serum D-dimer in patients with periprosthetic joint infection (PJI). Moreover, to provide evidence for the treatment of PJI by investigating distribution of pathogenic bacteria and antibiotic resistance situation among the patients. Methods: A retrospective study of the medical records of all patients undergoing arthroplasty from the Second Xiangya Hospital of Central South University from 2014 to 2018, 40 patients with periprosthetic joint infection, 37 patients with aseptic loosening and 59 patients with extra-articular infection were selected. The results of serum D-dimer, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were collected. As well as the bacterial types and antimicrobial susceptibility test results from tissue or joint fluid samples around the prosthetic joint of the patients were collected. All the relevant data were analyzed. Results: The serum D-dimer, CRP and ESR level were significantly higher in the patients with PJI. The mean D-dimer level was 2.0795 mu g/mL in PJI group compared with 0.6854 mu g/mL in aseptic loosening group (p = 0.000) and 0.4556 mu g/mL in extra-articular infection group (p = 0.000). For diagnosing PJI, the serum D-dimer test demonstrated better sensitivity (87.50%), and better specificity (89.19%); while the serum CRP and ESR had a sensitivity of 80.00% and 82.50% and a specificity of 78.38% and 64.86%, respectively. Moreover, the sensitivity and specificity of ESR and CRP combined was 75.00% and 83.78%, respectively. In addition, 29 strains of pathogens around the prosthesis after arthroplasty were detected, including 22 strains of Gram-positive bacteria, 3 strains of Gram-negative bacteria, and 4 strains of fungi. The staphylococcus was the major pathogen showing high resistance to Cefoxitin and ampicillin. Conclusion: Patients with PJI have high levels of serum D-dimer, which is a promising marker for the diagnosis of PJI. The Gram-positive bacteria are major pathogen in PJI after arthroplasty, and Staphylococcus aureus is the most common organism. Clinical efficacy is significantly improved by reasonable choice of antibiotics and effective medicine education.