Is it safe to prep the external fixator in situ during staged open reduction and internal fixation of distal tibial pilon fractures? A retrospective comparative cohort study. Pilon fractures involving the distal portion of the tibia are typically amongst the most challenging injuries treated by orthopedic surgeons and have often resulted in unsatisfactory postoperative outcomes, especially infection. As such, there has been an emphasis on determining the most optimal management for fixing pilon fractures. Initially, these fractures were treated with primary open reduction and internal fixation. However, prior studies found that initial stabilization using external fixation followed by open reduction of the fracture led to decreased complication rates and has been the prevailing method of treatment ever since. Unfortunately, while it has decreased in incidence, infection continues to be a common and severe challenge following treatment of pilon fractures, despite using the staged protocol. During the staged protocol, one method is to prep the entire X-fix into the surgical field or retain the intraosseous pins as this can provide stability and distraction. It may also improve efficiency and reduce costs. Conversely, another method is to remove the entire X-fix before prepping and exclude the pin sites from the sterile field in order to minimize contamination. Whether or not prepping in elements of the X-fix is a source of infection that typically follows pilon fracture fixation has yet to be assessed. As such, the purpose of this study is to compare the rates of infection and unplanned reoperation between patients with pilon fractures who had the X-fix prep into the surgical field and those who did not prior to undergoing staged open reduction and internal fixation. Given the results of previous studies, we hypothesize that while a variety of factors may predispose patients to infection and unplanned reoperation, the X-fix prep is not one of them. This study was approved by the University IRB. A multi-surgeon retrospective study was conducted on patients 18 years and older with pilon fractures who underwent operative treatment over a 10-year period between January 1, 2010 to January 1, 2020 at a single academic level one trauma center. All relevant cases at our institution were identified by querying the billing records for the treatment of pilon fractures. Medical records were reviewed for each patient to assess demographics, injury characteristics, and clinical results. Patients were then divided into two groups, those with any retained elements of the original X-fix prepped into the sterile field during surgery and those with the temporary X-fix completely removed prior to prepping and draping. Univariate analysis of the descriptive statistics as they pertain to patient and injury characteristics was calculated between groups of patients with and without the X-fix prepped in situ in order to identify variables that may be associated with the development of infection and unplanned reoperation. For the purposes of this study, unplanned reoperation is defined as the unexpected return to the operating room for further surgery, including amputation or arthrodesis. Subgroup analysis can further assess the associations between whether or not prepping the X-fix in situ correlated with specific bacteriology in patients who developed an infection. Independent sample t-tests and Pearson chi-square tests were used to evaluate the continuous and categorical variables, respectively. We found that a total of 133 patients met the final inclusion criteria for having a pilon fracture that was treated with staged open reduction and internal fixation. Of these patients, the overall rate of infection was 23.3% and the overall rate of unplanned reoperation was 11.3%. 64.7% of these patients had the entire X-fix construct removed prior to definitive fixation and 35.3% of these patients had at least one element of the X-fix prepped into the surgical field. Patients in these two groups were similar in terms of age, sex, race, BMI, proportion of active smokers or patients with diabetes, and proportion of open fractures. Furthermore, there was no significant difference in mechanism of injury or number of days from X-fix to definitive fixation between the two groups. With regard to postoperative results, there was no significant difference in infection or unplanned reoperation between the two cohorts. Interestingly, subgroup analysis found that upon assessing patients with infection, those with elements of the X-fix prepped in situ had a higher rate of infection with methicillin resistant and methicillin sensitive staph aureus. So in conclusion, we found that although there were relatively high complication rates in this cohort of pilon fractures treated with staged open reduction and internal fixation, prepping elements of the X-fix into the surgical field did not lead to a significant increase in the rates of infection or unplanned reoperation. We believe that this study offers clinical support regarding a common practice used to assist in the reduction and definitive fixation of pilon fractures. Thank you.

retrospective comparative cohort study

external fixator

distal tibial pilon fractures

infection rates

unplanned reoperation rates