Incidence and Risk Factors for Surgical Site Infection After Open Reduction and Internal Fixation of Ankle Fracture: A Retrospective Multicenter Study

SLR - April 2018 - Paul Whitehouse

Reference: Sun, Y, Wang, H, Tang, Y, Zhao, H, Qin, S, Xu, L, Xia, Z, Zhang, F. Incidence and Risk Factors for Surgical Site Infection After Open Reduction and Internal Fixation of Ankle Fracture: A Retrospective Multicenter Study. Medicine (Baltimore) 2018 Jan 25; 97(7).

Reviewed By: Paul J. Whitehouse, DPM
Residency Program: New Mexico VA Healthcare System, Albuquerque, NM

Podiatric Relevance: Understanding factors that may influence the probability of postoperative complication in those undergoing foot and ankle trauma is paramount to surgical planning. Particular concern in the traumatically injured patient is the development of infection, as previous studies have identified this as one of the most common complications in the postoperative period. The purpose of this study was to identify those factors that may influence infection in the patient who has had Open Reduction and Internal Fixation (ORIF) performed to correct ankle fracture.

Methods: This study is retrospective in nature and makes observations in the perioperative period in all patients who underwent ORIF for ankle fractures at three Level 1 trauma centers between January 2015 and December 2016 and who were 18 years of age or older. Patients were excluded for review when less than 18 years of age; fracture causation was pathologic; the fracture was untreated for >21 days; or when undergoing treatment other than ORIF. The electronic medical records of those fitting inclusion criteria were reviewed for the following factors: patient demographics, injury and surgical related characteristics and biochemical (laboratory) indicators. Particular interest was in postoperative surgical site infection (SSI), which was defined as deep or superficial.

Results: 1,510 patients met the inclusion criteria and had complete records for review. 4.37 percent, 66, of those included developed SSI, which was diagnosed through clinical signs and/or laboratory culture. Twenty infections were classified as deep and 46 as superficial. Patient characteristics identified through univariate analysis were entered into multivariate logistic regression model, which identified the following as significant risk factors for development of SSI: age (>50), linear association with increasing BMI (>24), high-energy injury, open injury, higher surgeon experience level, incision cleanliness (grade 2–4), history of allergy (unspecified), chronic heart disease and preoperative neutrophil count (> 75 percent). Use of intraoperative antibiotics was found to be a significant factor for reduced rate of postoperative SSI. Interestingly, diabetes mellitus, hypertension, smoking and alcohol use were not found to be related to the development of infection in this cohort.

Conclusions: The results from this study serve as an important reminder about the importance of understanding patient- and injury-specific factors for predicting postoperative infectious complications in patients. The retrospective design and diagnosis of the majority of infections through clinical signs are clear limitations of this study. However, there is great value to the data presented as it relates to adequate operative planning. Age, BMI, injury type, presence of allergy (unspecified), chronic heart disease and elevated neutrophil count are easily recognizable patient-specific factors, which may aid the foot and ankle surgeon in performing prophylactic measures and discussing with patients the likelihood of postsurgical infection.