The objectives of this study were to provide computed tomography (CT)-based description of the anatomic specifics of lateral compression (LC)-1 pelvic ring disruptions and to describe injury severity to other body systems and their correlation with fracture anatomy.
Retrospective radiographic assessment and review of records
A level 1 trauma and tertiary referral center.
We identified a consecutive series of 100 patients with Young and Burgess LC-1 pelvic ring disruptions from the trauma registry database at a level 1 trauma center and evaluated their radiographs, CT scans, and injury and admission information.
Main Outcome Measurements:
Presentation films were used to confirm injury type. The CT scan of the bony pelvis was reviewed for each patient by independent reviewers, with disagreement being resolved by the senior author. Sixteen categories were reviewed for each patient (rami fractures, segmental/comminuted rami fractures, Nakatani classification of rami fractures, anterior and posterior sacral fractures, and Denis classification). Sacral fractures were graded based on severity (0, no fracture; 1, buckle fracture; 2, simple fracture line; 3, comminuted fracture line). The age, Injury Severity Score (ISS), and 6 categories of Abbreviated Injury Scale (AIS) were recorded for each patient. A statistical analysis was performed to test the associations between fracture characteristics and injury severity.
Our group had 54 women and 46 men. The mean age was 37.84 ± 1.95. All patients but 3 had 1 or more rami fractures, and all but 2 had a sacral fracture. Of the 116 superior rami fractures, Nakatani 3 was the most common type (60/116, 51.7%). Of the 217 rami fractures, 47 (21.7%) were segmental or comminuted. Of the 98 anterior sacral injuries, there were 9 (9.2%) buckle fractures, 39 (39.8%) simple fractures, and 50 (51.0%) comminuted fractures. Of these 98 anterior sacral injuries, 47 (48.0%) were complete, passing through the sacrum and exiting the posterior cortex. Increasing severity of anterior sacrum fracture was associated with the presence of a complete sacral fracture (P < 0.0001). Of the 98 sacral fractures, 50 (50.0%) were Denis type 1, 41 (41.8%) Denis type II, and 7 (7.1%) Denis type III. Higher Denis types had higher likelihood of complete fractures of the sacrum (P < 0.0001). There was a significant association between the presence of a comminuted rami fracture and a complete sacrum injury (P = 0.003) and a trend to higher rates in Nakatani 2 superior rami fractures (P = 0.169). There were 4 deaths due to trauma in this group, and the mean ISS score was 17.16 ± 1.3. The highest mean system AIS score in these patients was extremity (2.42 ± 0.06) followed by chest (1.28 ± 0.17) and abdomen (1.03 ± 1.30). There was a trend to higher mean ISS scores (P = 0.2287) and significantly higher abdominal AIS scores (P = 0.0014) in those with a complete sacral fracture. Those with comminuted and complete sacral fractures were more likely to be symptomatic and require posterior ring stabilization (P = 0.003 and 0.043, respectively)
LC-1 fractures of the pelvic ring represent a spectrum of injuries, with a large proportion having complete disruption of the sacrum. This complete injury of the sacrum is predicted by Denis type, severity of anterior ring disruption, abdominal AIS, and potentially location of rami fracture and ISS. CT scanning best defines these injuries.