Negative Stress Examination Under Anesthesia Reliably Predicts Pelvic Ring Union Without Displacement.

Objectives: To identify the negative predictive value of examination under anesthesia (EUA) for determining pelvic ring stability and union without further displacement.
Design: Retrospective cohort study.
Setting: Two academic Level 1 trauma centers.
Patients/participants: Thirty-four adult patients with closed pelvic ring injuries treated over a 5-year period.
Interventions: Pelvic stress EUA.
Main Outcome Measures: Pelvic ring union and pelvic ring displacement at final follow-up.
Results: Thirty-four patients with closed pelvic ring injuries who underwent pelvic EUA during the study period and had a negative examination (indicating a stable pelvis) were identified. Mean age was 38 years (range 16-76), and 19 patients (55.9%) were male. Twenty-two patients (64.7%) had Young-Burgess lateral compression (LC)-1 injuries with complete sacral fractures, 4 patients (11.8%) had LC-2 injuries, and 8 patients (23.5%) had anteroposterior compression (APC)-1 injuries. Eight patients (23.5%) had associated injuries requiring restricted weight-bearing on one or both lower extremities and were excluded from the analysis. Immediate weight-bearing as tolerated was permitted bilaterally in the remaining 26 patients. Mean pelvic ring displacement at the time of injury was 3.8 mm (range 1-15 mm) for LC injuries and 9.1 mm (range 2-20 mm) for APC injuries. Patients were followed for a mean of 8 months (range 3-34 months). At final follow-up, mean displacement was 3.7 mm (range 0-17 mm) for LC injuries and 7.1 mm (range 2-19 mm) for APC injuries. Mean change in displacement from injury to union was -0.1 mm for LC injuries and -2.0 mm for APC injuries, indicating decreased pelvic ring displacement at union. All patients were able to tolerate full weight-bearing bilaterally with no pain, and there were no instances of delayed operative fixation after negative EUA.
Conclusions: Negative pelvic EUA after closed pelvic ring injury accurately predicts pelvic stability and union without displacement after nonoperative treatment with full weight-bearing bilaterally. Unless otherwise dictated by associated injuries, immediate weight-bearing as tolerated seems safe in patients with pelvic ring injuries who have had a negative EUA.
Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.