Geriatric patients presenting with isolated pubic rami fractures and inability to mobilize may have occult lateral compression pelvic ring injuries with dynamic instability.

Abstract

To determine the incidence of patients with isolated pubic rami fractures (PRFs) on computed tomography (CT) scans that have dynamic instability secondary to occult lateral compression (LC) pelvic ring injuries. Retrospective comparison study. Urban level one trauma centerPatients/Participants: Geriatric patients with isolated PRFs and inability to mobilize secondary to pain. Lateral stress radiographs (LSR) of pelvis to evaluate for ≥1 cm dynamic instability. Physical therapy (PT) clearance, hospital length of stay (LOS), discharge location. 19 patients were identified over 12 months. Patients were predominantly geriatric (median age: 75 years, interquartile range: 67 to 90), female (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% (8/19). Magnetic resonance imaging (MRI), 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 LOS. There was also trend for these patients to be unable to clear PT by discharge (63% (5/8) vs. 36% (4/11). The 90-day mortality rate of the cohort was 16% (3/19). Patients presenting with seemingly isolated PRFs on radiographs and CT scans that are unable to mobilize may have occult LC injuries with dynamic instability.