The Lateral Stress Radiograph Identifies Occult Instability of Lateral Compression Pelvic Ring Injuries Without Sedation
Joshua A. Parry, Motasem Salameh, Michael Maher, Stephen Stacey, Cyril Mauffrey
Abstract
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.