title: What are the patterns of injury and displacement seen in lateral compression pelvic fractures?
abstract: BACKGROUND
  Lateral compression (LC)-type pelvic fractures encompass a wide spectrum of injuries. Current classification systems are poorly suited to help guide treatment and do not adequately describe the wide range of injuries seen in clinical practice.
  
  
  OBJECTIVE
  We therefore (1) defined the spectrum of injuries that compose LC fractures with respect to both anterior and posterior ring injuries, with particular focus on the morphology of sacral fractures, and (2) identified fracture patterns associated with displacement at presentation.
  
  
  METHODS
  We retrospectively reviewed 318 LC pelvic fractures. Displacement of the anterior pelvic ring was identified and measured on plain radiographs and posterior displacement was identified by CT.
  
  
  RESULTS
  All 318 patients had an anterior injury and all but 13 (4%) had a posterior injury; 263 of the 318 fractures (87%) included a sacral fracture, with 162 of 318 (51%) having an anterior incomplete sacral fracture, 53 (17%) a complete simple fracture, and 48 (15%) a complete comminuted fracture. Forty-two of 318 (13%) had a crescent fracture. One hundred six of 318 (33%) were displaced at presentation. There was a higher incidence of initial displacement observed in fractures including bilateral rami fractures, a comminuted sacral fracture, or a crescent fracture.
  
  
  CONCLUSIONS
  LC pelvic fractures represent a heterogeneous group of injuries with a wide range of associated fracture patterns. In particular, there is a wide range of fracture types represented by injuries classified as LC1 (involving any sacral fracture). Fractures with more complex sacral fractures, crescent fractures, or bilateral pubic rami fractures tend to have higher degrees of initial displacement.
  
  
  METHODS
  Level IV, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Weaver
authors.forename: Wendy
authors.initials: W
authors.lastname: Bruinsma
authors.forename: Eugene
authors.initials: E
authors.lastname: Toney
authors.forename: Erica
authors.initials: E
authors.lastname: Dafford
authors.forename: Mark S
authors.initials: MS
authors.lastname: Vrahas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D018460:Fractures, Comminuted / Q000000981:diagnostic imaging / Q000473:pathology; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000473:pathology*; D006617:Hip Dislocation / Q000473:pathology*; D006620:Hip Fractures / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010384:Pelvic Bones / Q000293:injuries*; D011859:Radiography; D012189:Retrospective Studies; D012447:Sacrum / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D055815:Young Adult