Geriatric Patients Presenting With Isolated Pubic Rami Fractures and Inability to Mobilize May Have Occult Lateral Compression Pelvic Ring Injuries With Dynamic Instability

Abstract

Objectives: To determine the incidence of patients with isolated pubic rami fractures on computed tomography scans who have dynamic instability secondary to occult lateral compression pelvic ring injuries. Design: Retrospective comparison study. Setting: Urban level 1 trauma center. Patients/Participants: This study included geriatric patients with isolated pubic rami fractures and inability to mobilize secondary to pain. Intervention: Lateral stress radiographs of pelvis to evaluate for ≥1 cm dynamic instability. Main Outcome Measurements: Physical therapy clearance, hospital length of stay, and discharge location. Results: A total of 19 patients were identified over 12 months. Patients were predominantly geriatric (median age: 75 years, interquartile range: 67 to 90), woman (11/19), with unilateral (17/19) comminuted distal rami fractures (12/19) sustained in ground-level falls (12/19). Dynamic instability was identified in 42% of patients (8/19). Magnetic resonance imaging, obtained in 6 of these patients, demonstrated occult posterior ring fractures in all cases. Patients with dynamic instability were more likely to have comminuted distal rami fractures (Nakatani type 1b) and a longer hospital length of stay. There was also a trend for these patients to be unable to clear physical therapy by discharge (63% (5/8) versus 36% (4/11)). The 90-day mortality rate of the cohort was 16% (3/19). Conclusions: Patients presenting with seemingly isolated pubic rami fractures on radiographs and computed tomography scans who are unable to mobilize may have occult lateral compression injuries with dynamic instability. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.