Review Question - QID 8922

The patient is a high-energy trauma patient with hemodynamic instability. Pelvic binders have demonstrated risk of masking pelvic ring injuries on computed tomography. The best and safest adjunctive evaluation is a fluoroscopic stress examination under anesthesia.

The patient presents with hemodynamic instability suggestive of shock and an obvious femoral shaft fracture. While femoral shaft fractures can create substantial blood loss into the thigh, the degree of hypotension suggests additional blood losses elsewhere. The CT scan demonstrating retroperitoneal hematoma without pelvic ring injury should raise suspicion for an occult pelvic ring injury as the application of a pelvic binder or shock-sheeting can mask pelvic fractures. The emergency medicine literature suggests removal of the binder and subsequent radiography to assess for injury to the pelvic ring. This may be a risky proposition if the patient truly does have an unstable injury and bleeding. Alternatively, fluoroscopic stress examination under anesthesia may be a safer and reliable option.

Swartz et. al. evaluated the sensitivity of CT for detecting pelvic ring injuries after the application of a pelvic binder. For patients with anteroposterior compression (APC) or vertical shear (VS) type fractures, CT was diagnostic for both anterior and posterior ring injuries in only 50% of cases. Lateral compression injuries were not statistically assessed in the study. The authors reported that fluoroscopic stress examination under anesthesia was an essential adjunct in evaluation of the pelvic ring when a patient presented to the hospital in a pelvic binder.

Clements et. al. report two cases of polytrauma patients who presented with hemodynamic instability, and arrived in the emergency room with a pelvic binder in place. Both patients underwent CT in the pelvic binder, and pelvic ring injuries were missed in both cases due to reduction performed by the binder. The authors recommended binder removal with subsequent radiography to assess the pelvic ring.

Illustrations A and B are taken directly from the Clements et al. study. Illustration A demonstrates two pelvic CT images from a polytrauma patient who presented to the trauma bay in a pelvic binder that was placed in the field. There is no evidence of pelvic ring injury. Illustration B is the pelvic radiograph obtained after removal of the binder and the resultant displacement of an unstable pelvic ring injury.

Incorrect Answers:
Answer 1: Removing the binder and obtaining adjunctive pelvic plain radiographs is an option, though in a hemodynamically unstable patient it may be unsafe to do so, and is therefore not the best option in this case.
Answer 3: Pelvic stress examination should be performed under anesthesia and in the operating room where surgical intervention can be performed if necessary.
Answer 4: As discussed, the CT may be a false negative in the setting of pelvic binder application.
Answer 5: While adjunctive pelvic radiographs may be useful, they may still demonstrate false negative results.