Utility of Common Biomarkers for Diagnosing Infection in Nonunion

Area of Science:

• Orthopedic Surgery
• Infectious Disease
• Diagnostic Accuracy

Background:

• Nonunion of bone fractures can be challenging to manage, with infection being a critical complication.
• Distinguishing between septic (infected) and aseptic (non-infected) nonunions is crucial for appropriate treatment.
• Standard laboratory tests, including leukocyte count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), are often used to aid in diagnosis.

Purpose of the Study:

• To evaluate the diagnostic utility of WBC, ESR, and CRP in differentiating septic from aseptic nonunions.
• To determine if these inflammatory markers can accurately predict the presence of infection at the nonunion site.

Main Methods:

• A cohort study design was employed at a quaternary referral center.
• 211 nonunions requiring surgery were included, with blood samples collected preoperatively for WBC, ESR, and CRP analysis.
• Diagnostic accuracy measures were calculated, and logistic regression models were used to assess the predictive value of each test, adjusting for preoperative antibiotics.

Main Results:

• The prevalence of infection among the nonunions was 19%.
• Positive likelihood ratios for WBC, ESR, and CRP were low and not statistically significant in predicting infection.
• Multivariable analysis indicated that WBC, ESR, and CRP were not significant predictors of infection in this cohort.

Conclusions:

• The study found that preoperative WBC, ESR, and CRP levels are not significant predictors for distinguishing septic from aseptic nonunions.
• These commonly used laboratory tests have limited diagnostic utility in identifying infection in nonunion cases.
• Further research may be needed to identify more reliable biomarkers for diagnosing infection in nonunions.