Analysis of Risk Factors and Association of Cluster of Differentiation (CD) Markers With Conventional Markers in Delayed Fracture Related Infection for Closed Fracture

Background: Fracture-related infections (FRI) remain a difficult consequence for orthopedic trauma patients, their relatives, the treating physicians, and the healthcare systems. Delayed fracture-related infection is an important step in the infection process that can be controlled by diagnosing and preventing it from moving to the next level. Neutrophils CD64 and CD66b were identified as sensitive indicators in the event of infection. Normal sequential changes, on the other hand, occur after surgery and are extremely high. They are back to normal on the 10(th) day after the operation. The aim of this study was, therefore, to examine the risk factors associated with fracture-related infection by comparing cluster of differentiation (CD) indicators with conventional markers and comparing them with gold standards culture reports. As a result, it could be an early sign of a closed fracture infection. Material & Methods: Between February 2020 and March 2021, 510 patients from the Department of Orthopedics at King George Medical University in Lucknow agreed to participate in the study. The study included patients who had a closed fracture and had undergone elective or emergency surgery. Blood was withdrawn before the surgery (baseline) on day one and again on the third, seventh, and 10(th) day after the operation to measure the quantitative measurements of the biomarkers (total leucocyte count [TLC], erythrocyte sedimentation rate [ESR], C reactive protein [CRP], CD64, and CD66b) in all follow-up examinations. Patients were monitored for delayed signs of the infection for 2 to 10 weeks. The biomarkers were evaluated and linked to the culture reports. Results: Of the 510 patients included, 272 were men (53.3%) and 238 women (46.7%), the mean age was 40 (20-78), the mean age for fracture related infection with positive culture (FRI POS) was 48.0 (SD: 19.47), for fracture related infection with negative culture (FRI NEG) was 46.20 (SD: 17.18), and for patient with no signs of infections (NON-FRI) was 45.13 (SD: 17.62) (p <0.001), the mean duration of the fracture to admission (in hours) was 4.90 (SD: 1.92), 4.91 (SD: 2.65), and 5.14 (SD: 2.66) (p <0.001), respectively. The mean duration of admission to surgery (in hours) was 31.54 (SD: 85.14), 43.14 (SD: 105.64), and 61.84 (134.14), respectively (p <0.001). The mean duration of surgery was 4.63 (SD: 1.85), 5.14 (SD: 2.16), and 5.05 (SD: 2.16) (p <0.001). The risk factors such as bone type (p = 0.04) and addiction (p = 0.01) were identified as statistically significant. There was no correlation between the CD66b markers on the third, seventh, and 10(th) days. CD64 was significantly correlated with ESR, TLC, and CRP on the 10(th) day in the FRI-positive group (r = 0.638; p = 0.03) (r = 0.744; p = 0.009) (r = 0.817; p = 0.002). Conclusion: The risk factors for infection in fracture patients are significantly influenced by the type of bone and addiction the patient is using. Elevated CD64 levels could be used as a diagnostic marker for infection early on the 10(th) day after surgery before the appearance of clinical signs.