Pelvic injury prognosis is more closely related to vascular injury severity than anatomical fracture complexity: the WSES classification for pelvic trauma makes sense

BACKGROUND: The most common cause of death in cases of pelvic trauma is exsanguination caused by associated injuries, not the pelvic injury itself. For patients with relatively isolated pelvic trauma, the impact of vascular injury severity on outcome remains unclear. We hypothesized that the severity of the pelvic vascular injury plays a more decisive role in outcome than fracture pattern complexity. METHODS: Medical records of patients with pelvic fracture at a single center between January 2016 and December 2017 were retrospectively reviewed. Those with an abbreviated injury scale (AIS) score ≥ 3 in areas other than the pelvis were excluded. Lateral compression (LC) type 1 fractures and anteroposterior compression (APC) type 1 fractures according to the Young-Burgess classification and ischial fractures were defined as simple pelvic fractures, while other fracture types were considered complicated pelvic fractures. Based on CT, vascular injury severity was defined as minor (fracture with or without hematoma) or severe (hematoma with contrast pooling/extravasation). Patient demographics, clinical parameters, and outcome measures were compared between the groups. RESULTS: Severe vascular injuries occurred in 26 of the 155 patients and were associated with poorer hemodynamics, a higher injury severity score (ISS), more blood transfusions, and a longer ICU stay (3.81 vs. 0.86 days, p = 0.000) and total hospital stay (20.7 vs. 10.1 days, p = 0.002) compared with minor vascular injuries. By contrast, those with complicated pelvic fractures (LC II/III, APC II/III, vertical shear, and combined type fracture) required a similar number of transfusions and had a similar length of ICU stay as those with simple pelvic fractures (LC I, APC I, and ischium fracture) but had a longer total hospital stay (13.6 vs. 10.3 days, p = 0.034). These findings were similar even if only patients with ISS ≥ 16 were considered. CONCLUSIONS: Our results indicate that even in patients with relatively isolated pelvic injuries, vascular injury severity is more closely correlated to the outcome than the type of anatomical fracture. Therefore, a more balanced classification of pelvic injury that takes both the fracture pattern and hemodynamic status into consideration, such as the WSES classification, seems to have better utility for clinical practice.