Definitive Fixation Timing and Orthopedic Events After Polytrauma With Long Bone Fractures: A Secondary Cohort Analysis

Background: The timing of definitive fixation in polytrauma patients with long bone fractures must balance the benefits of early skeletal stabilization against the risks of operative stress in physiologically unstable patients. This study evaluated whether definitive fixation performed more than 24 hours after injury was associated with early orthopedic procedural events and broader adverse orthopedic outcomes. Methods: We performed a secondary retrospective cohort analysis of 115 adult polytrauma patients with operatively treated long bone fractures. Early definitive fixation was defined as fixation within 24 hours (≤24 hours) after injury, and delayed fixation was defined as fixation more than 24 hours after injury. The primary endpoint was an early orthopedic procedural event, defined as deep surgical site infection within 90 days, reoperation by six months, or bone graft/biologic augmentation by six months. Secondary endpoints included a broader adverse orthopedic course, delayed union at 24 weeks, clinical union at 24 weeks, and nonunion at nine months. Continuous variables were compared using Welch's t-test. Categorical variables were compared using Pearson's chi-square test when expected cell counts were adequate and Fisher's exact test when expected cell counts were low. Logistic regression was used for exploratory adjusted analyses. Results: Definitive fixation was performed within 24 hours in 33 patients (28.7%) and after 24 hours in 82 patients (71.3%). The primary procedural endpoint occurred in 20/115 patients (17.4%) and did not differ significantly between groups (4/33 patients (12.1%) vs. 16/82 patients (19.5%); chi-square = 0.895; p = 0.344). The broader adverse orthopedic course was more frequent after fixation beyond 24 hours (40/82 patients (48.8%) vs. 7/33 patients (21.2%); chi-square value = 7.400; p = 0.007). Delayed union at 24 weeks was also more frequent in the delayed fixation group (34/82 patients (41.5%) vs. 5/33 patients (15.2%); chi-square value = 7.269; p = 0.007). In adjusted analysis, fixation after 24 hours remained associated with the broader adverse orthopedic course (adjusted odds ratio = 3.00; 95% confidence interval = 1.09-8.25; z value = 2.124; p = 0.034), but not with the primary procedural endpoint. Conclusions: In this secondary cohort analysis, definitive fixation beyond 24 hours was not independently associated with early orthopedic procedural events, but it was associated with a broader adverse orthopedic course driven mainly by delayed union. These findings support a cautious interpretation of fixation timing as both a potentially modifiable treatment factor and a marker of underlying physiologic and injury-pattern complexity.