Timing of Femoral Shaft Fracture Fixation Affects Length of Hospital Stay in Patients with Multiple Injuries.

PURPOSE: Appropriate timing of definitive fracture care in the setting of polytrauma remains controversial. The aim of this study is to determine whether timing of definitive fixation of femur fractures impacts subsequent length of hospital stay, a surrogate for postoperative morbidity, in patients with multi-system trauma.

METHODS: Secondary analysis of data from the National Trauma Data Bank (January 1, 2000 to December 31, 2004) was performed. Adult patients who: (1) had an open or closed femoral shaft fracture, (2) had an injury severity score (ISS) greater than or equal to 15, (3) and underwent definitive internal fixation were included. Time to fixation was divided into 5 time periods based on commonly used cut-off points from the literature: (1) 12 hours or less, (2) between 12 and 24 hours, (3) between 24 and 48 hours, (4) between 48 and 120 hours, and (5) more than 120 hours. Because we consider length of stay a surrogate for adverse outcome causally affected by treatment time, the outcome variable was calculated as the duration of hospitalization following definitive treatment. Time to definitive fixation and its effect on post-treatment length of hospital stay was analyzed using median regression with inverse probability of treatment-weighting (IPTW) to control for confounding factors.

RESULTS: Compared to fixation during the first 12 hours after admission, median length of hospital stay was significantly higher (2.77 days; 95% confidence interval, 0.54 to 4.72) when fixation occurred between 48 and 120 hours from admission. Among the other time intervals, only treatment between twelve to twenty-four hours after admission was shown to reduce length of stay (-0.61 days; 95% confidence interval, -1.53 to 0.42) versus the referent interval of the first 12 hours, though this result did not achieve statistical significance. In order to assess the impact of shorter recorded length of stay for deceased patients, sensitivity analysis was conducted excluding all patient that underwent definitive treatment and died. Results were nearly identical for the second analysis, showing a higher post-treatment length of stay estimated for the population treated between 48 and 120 hours versus had they been treated within the first 12 hours from admission (2.53 days, 95% confidence interval, 0.27 to 4.13).

CONCLUSION: Delayed fixation of femoral shaft fractures in patients with multiple injuries between 2-5 days may lead to an increase in adverse outcomes as evidenced by increased median length of hospital stay. This finding supports prior clinical reports of a perilous period where a "second hit" resulting from definitive internal fixation can occur. Whether there is an optimal window for fixation during which physiologic stress of fracture fixation does not adversely lengthen hospital stay should be the subject of future prospective study.