Effect of surgical fixation timing on in-hospital mortality and morbidity of distal femur fractures

Introduction: The literature lacks a large-scale study investigating the effect of surgical fixation timing on early mortality and morbidity outcomes in distal femur fractures. The aims of this study were to determine the effect of fixation timing on in-hospital mortality and morbidity outcomes for operatively treated distal femur fractures retrospectively using large database data.

Methods: This study is a retrospective analysis using data from the National Trauma Data Bank. Patients were stratified into a fragility cohort (age ≥ 60, ISS < 16) and polytrauma cohort (age < 60, ISS ≥16), with both cohorts analyzed separately. Within each cohort, patients were split into three fixation timing groups: within 24 h, between 24 and 48 h, and greater than 48 h from presentation to the hospital. Fixation-timing groups were compared based on the primary outcome of in-hospital mortality rate. Secondary outcomes included hospital length of stay (LOS), ICU length of stay (ICU LOS), days on a ventilator, and complications.

Results: The fragility and polytrauma cohorts included 22,045 and 5,905 patients, respectively. The in-hospital mortality rate was 1.23 % in the fragility cohort and 2.56 % in the polytrauma cohort. Multivariate analysis of the fragility cohort showed that fixation greater than 48 h from time of presentation was associated with increased mortality compared to fixation within 24 h (OR 1.89, CI: 1.26-2.83, p=0.002) and between 24 and 48 h (OR 1.63, CI: 1.23-2.15, p<0.001). In the polytrauma cohort, multivariate analysis showed no significant mortality differences between fixation timing groups. Multivariate analysis of morbidity outcomes in both cohorts showed that fixation greater than 48 h was associated with increased LOS, ICU LOS, ventilator days, and complications compared to fixation within 24 h. In the polytrauma cohort, fixation between 24 and 48 h was associated with decreased LOS, ICU LOS, and complications compared to the other two timing groups.

Conclusions: Fixation of distal femur fractures before 48 h from presentation may lead to improved mortality and morbidity in older, lower injury severity patients. No significant mortality benefit was observed in younger, polytrauma fractures. Further prospective work is needed to validate these findings.