Timing of femoral shaft fracture fixation following major trauma: A retrospective cohort study of United States trauma centers

Background
Femoral shaft fractures are common in major trauma. Early definitive fixation, within 24 hours, is feasible in most patients and is associated with improved outcomes. Nonetheless, variability might exist between trauma centers in timeliness of fixation. Such variability could impact outcomes and would therefore represent a target for quality improvement. We evaluated variability in delayed fixation (≥24 hours) between trauma centers participating in the American College of Surgeons (ACS) Trauma Quality Improvement Program (TQIP) and measured the resultant association with important clinical outcomes at the hospital level.
Methods and findings
A retrospective cohort study was performed using data derived from the ACS TQIP database. Adults with severe injury who underwent definitive fixation of a femoral shaft fracture at a level I or II trauma center participating in ACS TQIP (2012–2015) were included. Patient baseline and injury characteristics that might affect timing of fixation were considered. A hierarchical logistic regression model was used to identify predictors of delayed fixation. Hospital variability in delayed fixation was measured using 2 approaches. First, the random effects output of the hierarchical model was used to identify outlier hospitals where the odds of delayed fixation were significantly higher or lower than average. Second, the median odds ratio (MOR) was calculated to quantify heterogeneity in delayed fixation between hospitals. Finally, complications (pulmonary embolism, deep vein thrombosis, acute respiratory distress syndrome, pneumonia, decubitus ulcer, and death) and hospital length of stay were compared across quartiles of risk-adjusted delayed fixation.
We identified 17,993 patients who underwent definitive fixation at 216 trauma centers. The median injury severity score (ISS) was 13 (interquartile range [IQR] 9–22). Median time to fixation was 15 hours (IQR 7–24 hours) and delayed fixation was performed in 26% of patients. After adjusting for patient characteristics, 57 hospitals (26%) were identified as outliers, reflecting significant practice variation unexplained by patient case mix. The MOR was 1.84, reflecting heterogeneity in delayed fixation across centers. Compared to hospitals in the lowest quartile of delayed fixation, patients treated at hospitals in the highest quartile of delayed fixation suffered 2-fold higher rates of pulmonary embolism (2.6% versus 1.3%; rate ratio [RR] 2.0; 95% CI 1.2–3.2; P = 0.005) and required greater length of stay (7 versus 6 days; RR 1.15; 95% CI 1.1–1.19; P < 0.001). There was no significant difference with respect to mortality (1.3% versus 0.8%; RR 1.6; 95% CI 1.0–2.8; P = 0.066). The main limitations of this study include the inability to classify fractures by severity, challenges related to the heterogeneity of the study population, and the potential for residual confounding due to unmeasured factors.
Conclusions
In this large cohort study of 216 trauma centers, significant practice variability was observed in delayed fixation of femoral shaft fractures, which could not be explained by differences in patient case mix. Patients treated at centers where delayed fixation was most common were at significantly greater risk of pulmonary embolism and required longer hospital stay. Trauma centers should strive to minimize delays in fixation, and quality improvement initiatives should emphasize this recommendation in best practice guidelines.

【背景】股骨干骨折（Femoral shaft fractures）在严重创伤中较为常见。多数患者可在24小时内接受早期确定性固定术，且该方案与更佳预后相关。然而，不同创伤中心在固定术及时性方面或存在差异，这种差异可能影响患者预后，因此可作为质量改进的目标。本研究评估了参与美国外科医师学会（American College of Surgeons, ACS）创伤质量改进项目（Trauma Quality Improvement Program, TQIP）的各创伤中心在延迟固定术（≥24小时）方面的差异，并分析了其与医院层面重要临床结局的关联。

【方法与结果】本研究采用ACS TQIP数据库的数据开展回顾性队列研究。纳入2012至2015年间，在参与ACS TQIP的一级或二级创伤中心接受股骨干骨折确定性固定术的严重创伤成年患者。研究考量了可能影响固定术时机的患者基线特征与损伤特征。采用分层logistic回归模型识别延迟固定术的预测因素。通过两种方法评估各医院在延迟固定术方面的差异：其一，利用分层模型的随机效应输出，识别延迟固定术发生率显著高于或低于平均水平的异常值医院；其二，计算中位数优势比（median odds ratio, MOR）以量化不同医院间延迟固定术的异质性。最终，按风险校正后的延迟固定术四分位分层，比较各组的并发症（肺栓塞、深静脉血栓形成、急性呼吸窘迫综合征、肺炎、压疮及死亡）与住院时长。
本研究共纳入216家创伤中心的17993例接受确定性固定术的患者，其损伤严重程度评分（ISS）中位数为13（四分位距[IQR] 9~22）。固定术中位时间为15小时（IQR 7~24小时），26%的患者接受了延迟固定术。在校正患者特征后，共识别出57家（26%）异常值医院，提示存在无法通过患者病例组合解释的显著诊疗实践差异。本次研究的中位数优势比为1.84，反映出各中心在延迟固定术方面存在异质性。与延迟固定术发生率最低四分位组的医院相比，收治于发生率最高四分位组医院的患者，其肺栓塞发生率翻倍（2.6% vs 1.3%；率比[RR] 2.0；95%置信区间[CI] 1.2~3.2；P=0.005），且住院时长更长（7天 vs 6天；RR 1.15；95%CI 1.1~1.19；P<0.001）。两组患者的死亡率无显著差异（1.3% vs 0.8%；RR 1.6；95%CI 1.0~2.8；P=0.066）。本研究的主要局限性包括：无法按严重程度对骨折进行分类、研究人群存在异质性带来的挑战，以及未测量因素导致的残余混杂风险。

【结论】在这项涵盖216家创伤中心的大型队列研究中，本研究观察到股骨干骨折延迟固定术存在显著的诊疗实践差异，且该差异无法通过患者病例组合的不同加以解释。收治于延迟固定术最为常见的中心的患者，其肺栓塞风险显著更高，且住院时长更长。各创伤中心应尽力缩短固定术的延迟时间，质量改进举措也应在最佳实践指南中强调该推荐意见。