New scoring system predicting the occurrence of deep infection in open upper and lower extremity fractures: efficacy in retrospective re-scoring

Abstract

It is important to predict the occurrence of deep infection in open fractures when treating such fractures. We tried to develop a new scoring system for predicting the occurrence of deep infection in open upper and lower extremity fractures on the basis of the Hannover Fracture Scale'98 (HFS-98). A total of 394 open upper and lower extremity fractures (351 patients) were retrospectively reviewed in the initial analysis. The relationship between Gustilo's grade and the eight items on HFS-98 in the open extremity fractures was first investigated by multivariate analysis. By this analysis, we selected significant items that correlated with Gustilo's grade. Among these cases, 318 patients with 352 open extremity fractures (humerus = 27, forearm = 62, femur = 76, tibia = 187) were used for the following infection analyses. The relationships between the incidence of deep infection and sex (male or female), age (<30, 30-50, <50 years), grade of polytrauma (ISS < 18, 18 < or = ISS < or = 30, ISS > 30), site of fracture (humerus, forearm, femur, tibia), existence of fracture line around joint (+ or -) or some significant items in the above initial analysis were further analyzed by multivariate analysis after univariate analysis. We devised a new scoring system of open extremity fractures based on P values in the above analysis. The discrimination of the newly devised scoring system was evaluated with receiver operating characteristic (ROC) curves. The following factors: muscle injury (MI, P = 0.0001); wound contamination (WC, P = 0.0001); and local circulation (LC, P = 0.0001) were significant factors affecting the occurrence of deep infection on multivariate analysis. We devised a new scoring system for open extremity fractures (MI: 0-20 points, WC: 0-20 points, and LC: 0-20 points). The cut-off point for occurrence of deep infection in these fractures was 35 by ROC analysis. This new scoring system was thought to be useful for predicting the occurrence of deep infection in open extremity fractures. However, further prospective study or multicenter study would be needed to clarify the validity of this scale.