Does Time to Pelvic Fixation Influence Outcomes in Trauma Patients?

Key Takeaways

There is no optimal time window established for fixation of pelvic fractures in trauma patients as previous studies on time to fixation have been vague and restrictive in their applicability to a polytrauma patient.

Introduction

Pelvic fractures are a major contributor to the morbidity and mortality of the trauma patient. Stabilization of long bone fractures within 24 hours of presentation is accepted as the current standard of care. ¹ Similar to femur fractures, the benefits of early operative fixation of pelvic fractures are not disputed in the literature. Vallier and colleagues ¹ showed that early fixation of pelvic and acetabular fractures reduced morbidity and length of ICU stay, especially in patients with severe chest injuries. Other studies have shown that early fixation of acetabular fractures was associated with reduced length of stay (LOS) and lower incidence of organ dysfunction. ² Additionally, patients undergoing early acetabular fracture fixation are discharged home at higher rates as opposed to a skilled nursing or rehab facility, which demonstrates improved functional outcomes. ² Multiple retrospective analyses have shown improved outcomes as trauma centers adopt protocol changes pushing for earlier fixation and improved coordination between trauma teams and their orthopedic colleagues to minimize delay in treatment.^3-11

Given the high-energy mechanism required to cause a pelvic fracture, many of these patients have life-threatening concomitant injuries that impact the overall time to definitive pelvic fixation. Factors such as the need for more emergent surgical procedures, complex ventilator management, or resuscitation can influence the time to fixation of pelvic fractures causing a noted, but often necessary, delay in fixation. Defined algorithms between trauma surgeons and orthopedic traumatologists are proven to improve patient survival through reduction in early deaths from pelvic hemorrhage, as well as later deaths from multiorgan failure. ³ Guidelines have yet to define a specific optimal window when pelvic fractures should undergo operative fixation. No previous study has identified the optimal time from admission to operative fixation of pelvic fractures. The objective of this study was to determine if the time to final fixation of pelvic fractures within 3 days or greater than 3 days affected the hospital course of the injured patient at a Level I trauma center. It was hypothesized that patients with fixation within 3 days would have improved outcomes and a shorter LOS.

Methods

A retrospective chart review of all consecutive adult patients who presented to a Level 1 trauma center with pelvic fractures that required operative fixation between January 1, 2016 and July 19, 2020 was performed. Exclusion criteria were patients who did not ultimately undergo pelvic fixation surgery, non-survivable traumatic brain injury, mortality within 24 hours, prolonged hospital stay due to social issues, and members of vulnerable populations (patients younger than 18 years of age, pregnant women, and prisoners). Institutional Review Board approval and a Health Insurance Portability and Accountability Act waiver of informed consent were obtained from Louisiana State University.

The trauma registry query search filters included patients with pelvic fractures who underwent pelvic procedures in the operating room. Additional search queries were also applied to identify in-hospital complications of ventilator-associated pneumonia (VAP), deep venous thrombosis (DVT), pulmonary embolism (PE), acute kidney injury (AKI), surgical site infection (SSI), decubitus ulcer, acute respiratory distress syndrome (ARDS), abdominal compartment syndrome, unplanned intubation, unplanned intensive care unit (ICU) admission, unplanned operating room procedure, and cardiac arrest. Patients undergoing pelvic angioembolization by our Interventional Radiology team were flagged with terms “angioembolization,” “radiographic embolization,” or “pelvic embolization.”

Patient demographics and injury statistics such as age, gender, race, mechanism of injury, Injury Severity Score (ISS), and LOS in days from admission to discharge were recorded. “Staged pelvic procedure” was defined as placement of an external fixator followed by open reduction and internal fixation at a later date. A “life-saving procedure” was defined as an emergent procedure that would have likely resulted in patient death or significant disability if not performed immediately. Most commonly these priority procedures included decompressive craniotomies, repair of unstable spinal fractures, and exploratory laparotomies. Time to fixation was defined as either the interval in days between admission and completed pelvic fixation or between completion of life-saving procedure and completed pelvic fixation. Patients were stratified into 2 groups, EARLY and LATE, with EARLY defined as time to fixation within 3 days and LATE defined as time to fixation greater than 3 days. The primary outcome measured was LOS. Secondary outcomes included complications and in-hospital mortality.

Results were analyzed using an unpaired Student’s t-test for continuous variables and Fisher’s exact test for categorical variables using GraphPad (version 5, La Jolla, CA) and IBM SPSS (version 27, Armonk, NY). A multiple linear regression was performed for variables with P < .2 on univariate analysis. A P value <.05 was considered to be statistically significant. Results are presented as mean +/− standard error of the mean (SEM) unless otherwise noted.

Results

Study Population

A total of 333 patient charts were reviewed with 38 patients being excluded as they did not meet inclusion criteria of having undergone pelvic fixation surgery for repair of a traumatic pelvic fracture. An additional 2 patients were removed due to prolonged LOS due to social issues. Finally, 6 patients were removed who had sustained non-survivable traumatic brain injury or who were critically ill and their cause of death was due to an etiology unrelated to their pelvic fracture. A total of 287 patients were included in the study with 179 patients in the EARLY group and 108 in the LATE group (Figure 1) (Table 1).

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Figure 1.

Flowchart of patient selection and exclusion.

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Figure 2.

Percentage of patients remaining by LOS in EARLY and LATE fixation groups.

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Table 1.

Patient Demographics and Study Outcomes for Trauma Patients Undergoing Pelvic Fixation.

Demographics	All patients n = 287	EARLY n = 179	LATE n = 108	P value
Age, mean, yrs (SEM)	41.9 (.9)	43.0 (1.2)	40.1 (1.5)	.14
Male gender, n (%)	201 (70.0)	130 (72.6)	71 (65.7)	.23
Race, African American, n (%)	118 (41.1)	76 (42.5)	42 (38.9)	.62
Race, White, n (%)	145 (50.5)	87 (48.6)	58 (53.7)	.46
Blunt trauma, n (%)	281 (97.9)	176 (98.3)	105 (97.2)	.68
ISS, mean, yrs (SEM)	15.9 (.6)	14.9 (.8)	17.7 (1.1)	.04*
Staged pelvic procedure, n (%)	24 (8.4)	8 (4.5)	16 (14.8)	.004*
Life-saving operation prior to pelvic fixation, n (%)	83 (31.0)	54 (30.2)	29 (26.9)	.59
Pelvic embolization, n (%)	54 (18.8)	36 (20.1)	18 (16.7)	.53

Abbreviations: SEM, standard error of the mean; ISS, Injury Severity Score. *Denotes statistical significance (P < .05).

Complications

There was no significant difference in rates of VAP, DVT, PE, AKI, pressure ulcer, ARDS, unplanned ICU admission, unplanned OR procedure, or cardiac arrest (P > .05). There was a significant difference in the rate of SSI with fewer in the earlier fixation group, 2.8% vs 8.3% (P = .04). After multiple linear regression adjusting for covariates of age and ISS, the difference in LOS was 5.5 days (95% CI −8.0 to −3.1, P < .001) (Table 2).

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Table 2.

Clinical Outcomes for Trauma Patients Undergoing Pelvic Fixation.

Clinical outcomes	All patients n = 287	EARLY n = 179	LATE n = 108	P value
LOS, mean days (SEM)	14.2 (.7)	11.9 (.7)	18.0 (1.2)	<.001*
Complications, n (%)
Mortality related to pelvic fracture	1 (.3)	1 (.6)	0 (0)	1.0
VAP	4 (1.4)	1 (.6)	3 (2.8)	.15
DVT	9 (3.1)	3 (1.7)	6 (5.6)	.09
PE	6 (2.1)	5 (2.8)	1 (.9)	.42
AKI	4 (1.4)	3 (1.7)	1 (.9)	1.0
SSI	14 (4.9)	5 (2.8)	9 (8.3)	.04*
Pressure ulcer	4 (1.4)	2 (1.1)	2 (1.9)	.63
ARDS	1 (.3)	0 (0)	1 (.9)	.38
Abdominal compartment syndrome	2 (.7)	2 (1.1)	0 (0)	.53
Unplanned intubation	6 (2.1)	3 (1.7)	3 (2.8)	.68
Unplanned ICU admission	12 (4.2)	6 (3.4)	6 (5.6)	.38
Unplanned OR procedure	6 (2.1)	3 (1.7)	3 (2.8)	.68
Cardiac arrest	2 (.7)	1 (.6)	1 (.9)	1.0

Abbreviations: SEM, standard error of the mean; LOS, length of stay; VAP, ventilator-associated pneumonia; DVT, deep vein thrombosis; PE, pulmonary embolism; AKI, acute kidney injury, SSI, surgical site infection, ARDS, acute respiratory distress syndrome. *Denotes statistical significance (P < .05).

Discussion

This study demonstrated a decreased LOS after fixation within 3 days, identifying an optimal and practical window for definitive pelvic fracture fixation in the complex trauma patient. Decreased LOS is an apt surrogate for patient well-being, as those with improved pain control, earlier mobilization, and overall improved clinical status with few complications tend to be discharged earlier. Previous studies concluded that early pelvic fracture fixation demonstrated decreased mortality, LOS, and complications. However, many of these studies cite first pelvic fracture intervention within 24 hours as a metric while this study defined time to fixation after definitive pelvic fracture surgery was completed. Defining time to fixation in this way aligns with the fact that the most significant benefit of pelvic fixation is return to mobility, which can only be obtained after a patient’s definitive pelvic fixation has occurred.

A previous study by Riemer et al demonstrated a mortality benefit in patients with fractures of the pelvic ring after an institutional protocol change resulted in earlier mobility via earlier external fixation, while patients without pelvic fractures did not see the same mortality benefit over that period. Though the benefits of early stabilization are even more drastic in the hypotensive trauma patient, the benefits of stabilization are beyond the tamponade effect of reducing pelvic volume. Early mobilization to an upright chest position provided by early external fixation followed by earlier ambulation from earlier definitive fixation results in compounding benefits. Earlier studies did not pinpoint the exact interval from time of insult to fixation that would be optimal. Riemer’s retrospective analysis was more indirect as it evaluated outcomes before and after a protocol change and patients underwent fixation only when deemed necessary. Therefore, like the Plaisier study, a smaller number of patients actually underwent operative fixation comparatively. The current study was more directed as it only included patients undergoing operative pelvic fixation. ⁵ Plaisier also saw reduced LOS in the early group. As opposed to comparison of fixation 24 hours from admission to fixation at over 24 hours, this study’s comparison of within 3 days to greater than 3 days is more realistic. Limiting an early fixation group to 24 hours excludes polytrauma patients requiring triage, resuscitation, or emergent life-saving procedure who underwent pelvic fixation promptly when cleared by the primary trauma team. Similar to Plaisier, Vallier and Enninghorst examined fixation within 24 hours compared to greater than 24 hours. Vallier did not demonstrate a significant difference in LOS but showed fewer ICU days, pulmonary complications, ARDS, and overall complications in their early group. Like many other studies, they examined fractures by type, including multiple fracture classification systems. ² All of the patients in the late group of the Enninghorst study had a staged procedure with an earlier placed external fixator within 24 hours from admission, which is quite different from this study, and begs the question as to how many of those patients required a life-saving priority procedure while allowing time for fixator placement all within 24 hours. Different from this study, the goal of the Enninghorst study was to demonstrate the safety of a single stage pelvic fixation as they did not demonstrate a statistically significant difference in transfusion rates, DVTs, PEs, pneumonia, ICU LOS, LOS, or mortality. ¹² Vallier’s mean ISS of 26.9 and 24.9 in EARLY and LATE groups compared to 14.9 and 17.7 in this study makes direct comparison difficult. The current study excluded mortalities unrelated to pelvic fracture and non-survivable TBIs, which may be the reason for the mean ISS difference between the studies. The Vallier study’s reduction of pulmonary complications, ARDS, and multi-system organ failure was more exaggerated in a sub-group of patients with ISS >18. ¹ This finding begs the question as to whether or not the current study would have seen statistically significant differences in more complications with a similar sub-group analysis. Finally, the Latenser study included only open or unstable pelvic fractures and only those with multiple associated injuries. It excluded those with ISS below 12. Like many earlier studies, they analyzed a much smaller group of 37 patients total with a much narrower definition of early fixation limited to within 8 hours from admission. ⁴

This study has several limitations that merit further discussion. First, this study is limited by its single institution and retrospective nature. Another limitation is that the study design did not allow for distinguishing a patient whose fixation was delayed due to requiring life-saving non-operative management including resuscitation with blood products or complex ventilator management. The study distinguished those patients only if they underwent a priority life-saving procedure in the operating room beforehand. Differentiation between a patient whose pelvic fixation was delayed due to the requirement of non-operative life-saving management compared to a patient whose operation was delayed due to operating room availability, surgeon scheduling conflicts, or surgeon preference is important. Undocumented delays to the OR due to limited availability could have been a confounding factor and was difficult to identify retrospectively.

In addition, this study did not include documented indication for pelvic fracture fixation in data collection such as bleeding, pelvic ring instability, wound contamination, or concomitant bladder injury, which is valuable for protocol development. Future multi-institutional prospective studies are needed to address the inherent limitations of this study.

Conclusions

This study investigated the impact of time to pelvic fixation on patient outcomes. The significant reduction in LOS without an increase in complications with earlier fixation of pelvic fractures merits further investigation through a multi-center prospective, randomized study.