The Lateral Stress Radiograph Identifies Occult Instability of Lateral Compression Pelvic Ring Injuries Without Sedation.

OBJECTIVES

To determine if pelvic ring displacement on the lateral stress radiograph (LSR) correlated with displacement on examination under anesthesia (EUA).

DESIGN

Retrospective cohort study.

SETTING

Urban Level I trauma center.

PATIENTS/PARTICIPANTS: Twenty consecutive patients with unilateral minimally displaced LC1 injuries with complete sacral fractures.

INTERVENTION

An anteroposterior pelvis radiograph taken in the lateral decubitus position (LSR) was performed on awake patients before EUA in the operating room.

MAIN OUTCOME MEASUREMENTS

Correlation between ≥1 cm of pelvic ring displacement on the LSR and EUA.

RESULTS

The LSR demonstrated ≥1 cm of displacement in 11 of the 20 patients (55%). All of these patients had ≥1 cm of displacement on EUA and underwent surgical fixation. The remaining 9 patients with <1 cm of displacement on the LSR also had <1 cm of displacement on EUA and were managed nonoperatively.

CONCLUSIONS

The LSR reliably identified occult instability in LC1 pelvic ring injuries and demonstrated 100% correlation with EUA. In contrast to EUA, the LSR does not require sedation and normalizes the amount of force applied to determine instability.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.