Review Question - QID 219203

The patient presents with hemodynamic instability in the setting of an unstable vertical shear pelvic ring injury. External tamponade measures are primarily aimed at the prevention of retroperitoneal hematoma expansion, most commonly from venous bleeding.

Initial treatment strategies for unstable vertical shear pelvic ring injuries include skeletal traction and pelvic binder or circumferential sheet application to stabilize the pelvis and control blood loss. Venous plexus injury and disrupted cancellous bone are among the most common sources of hemorrhage leading to potentially life-threatening extravasation into the retroperitoneal space, which can be lessened with early external compressive and stabilizing measures.

Stahel et al. reviewed hemodynamic instability associated with unstable pelvic ring injuries, underscoring the high historic mortality rates associated with retroperitoneal hemorrhage among these patients. Hemorrhage is largely attributed to presacral and paravesical venous plexus injury and fractured cancellous bone within the retroperitoneal space. They cited that less than 10% of traumatic hemorrhage arises from arterial sources amenable to embolization. Included protocolized approaches to unstable pelvic fracture management highlighted the role of initial pelvic binder application and the consideration of early retroperitoneal pelvic packing and external fixation to tamponade venous bleeding, with delayed angioembolization considered in cases of ongoing hemodynamic instability.

In a 2013 review, Langford et al. also discussed the initial management and resuscitation of pelvic injured patients, noting the importance of early external pelvic compression and the placement of skeletal traction when vertical instability is present to limit retroperitoneal hematoma expansion and improve hemodynamics. They further assessed the role of retroperitoneal pelvic packing in patients who remain hemodynamically unstable after initial binder or external fixator placement to control venous and bony bleeding, and potentially avoid unnecessary angiography, with only 10-15% of patients reported to have bleeding from an arterial source. They concluded that early external pelvic compression helps with hemorrhagic control by reducing retroperitoneal pelvic volume, stabilizing clot formation, and limiting ongoing soft tissue damage.

Figure A is an AP pelvis radiograph consistent with a vertical shear pelvic ring injury. There is a pubic symphysis diastasis and disruption of the left sacroiliac joint, with resultant cranial displacement of the left hemipelvis.

Incorrect Answers:
Answers 1&2: Venous plexus injury is reported to account for up to 90% of bleeding associated with pelvic ring injuries. Arterial bleeding is less common.
Answers 4&5: The retroperitoneal space is the most common location of hemorrhage addressed through external pelvic stabilization and compression in the setting of unstable fractures. Retroperitoneal hematoma is a potentially life-threatening sequela of venous bleeding associated with these injuries, as the retroperitoneal space can hold up to 4L of blood.