Resident University of Pennsylvania New Bolton Center Kennett Square, Pennsylvania
Serum Amyloid A and Fibrinogen as Markers for Early Postoperative Infection Associated with Internal Fixation in the Horse. Thurston CC, Stefanovski D, Richardson DW, Levine DG. University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, Department of Clinical Studies, Kennett Square, PA.
Postoperative infection (POI) in equine orthopedics is a significant complication associated with increased morbidity and mortality. Early therapy is needed for successful outcomes. Serum amyloid A (SAA) is a major acute phase protein in the horse that has been shown to be a sensitive marker of inflammation and infection. We hypothesized that SAA could be used to predict the development of POI in equine long bone fracture repair and arthrodesis and that it would be a more sensitive marker than fibrinogen. Horses undergoing internal fixation for fracture or arthrodesis were included in the study. SAA and fibrinogen were measured preoperatively and on days 1, 3, 5, 7, 10, and 14 postoperatively. Data was analyzed using Spearman’s correlation, logistic regression, and by calculating the area under the receiver-operator characteristic (ROC) curve. Both fibrinogen and SAA measurements were associated with POI, with SAA considered an excellent marker (area under the ROC curve > 0.8) and fibrinogen considered acceptable ( < 0.8). As the amount of time postoperatively increased, SAA elevations indicated a higher likelihood of POI (area under the ROC curve 0.7974) compared with fibrinogen (0.7167). These results confirmed our hypothesis that SAA and fibrinogen are predictive markers of POI and that SAA is a more sensitive marker than fibrinogen. Persistent elevations of SAA postoperatively may indicate the development of POI. Limitations of the study include small sample size and criteria for diagnosis of POI. SAA can be used to monitor horses undergoing fracture repair or arthrodesis for POI.