Abstract
Aim
Fracture related infection (FRI) remains a challenging diagnosis in orthopedic and trauma surgery. In addition to clinical signs and imaging, serum inflammatory markers are often used to estimate the probability of FRI. To what extent serum inflammatory markers can be used to rule out and diagnose FRI remains unclear. The aim of this systematic review was to assess the diagnostic value of the serum inflammatory markers C-reactive protein (CRP), leukocyte count (LC) and erythrocyte sedimentation rate (ESR) in suspected fracture related infection.
Method
PubMed, Embase and Cochrane databases were searched for all articles focusing on the diagnostic value of CRP, LC and ESR in FRI. Studies on other inflammatory markers or other types of orthopedic infection, such as periprosthetic and diabetic foot infections, were excluded. For each serum inflammatory marker, all reported sensitivity and specificity combinations were extracted and graphically visualized. Average estimates were obtained using bivariate mixed effects models. This study utilized the QUADAS-2 criteria and was reported following the PRISMA statement.
Results
The search resulted in 8280 articles, of which seven were eligible for inclusion. One study was excluded after quality assessment. CRP was reported in all included studies, with sensitivity ranging from 60.0 to 100.0% and specificity from 34.3 to 85.7%. Five of these studies were pooled. The average pooled sensitivity and specificity of CRP were, respectively, 77.0% (95% CI 66.5–85.0%) and 67.9% (95% CI 38.7–87.6%). LC was reported in five studies. Sensitivity ranged from 22.9 to 72.6% and specificity from 73.5 to 85.7%. The results of four of these studies were pooled, resulting in a 51.7% (95% CI 27.2–75.5%) sensitivity and 67.1% (95% CI 19.3–50.2%) specificity. ESR was reported in five studies. Sensitivity and specificity ranged from 37.1 to 100.0% and 59.0 to 85.0% respectively. Three of these studies were pooled, showing a 45.1% (95% CI 37.8–52.6%) sensitivity and 79.3% (95% CI 71.7–85.2%) specificity of ESR. Four studies analyzed the combined value of inflammatory markers, reporting an increased diagnostic accuracy. These results could not be pooled due to heterogeneity.
Conclusions
The serum inflammatory markers CRP, LC and ESR are insufficiently accurate to diagnose FRI. These markers cannot rule out the presence of FRI, but they may be used as a suggestive sign in the diagnosis of FRI.
