System used to describe pelvic fractures. Type 1A, avulsion fractures of anterior spine or ischial tuberosity; type 2A, fracture of 2 ipsilateral rami; type 2B, fracture/subluxation of symphysis pubis; type 2C, fracture/subluxation of sacroiliac joint; type 3A, 2 vertical fractures of pelvic ring or straddle dislocation of pubis; type 3B, 2 vertical fractures of pelvic ring or Malgaigne ring dislocation; type 3C, multiple ring fractures; type 4A, acetabular fracture with nondisplaced pelvic fracture; type 4C, linear acetabular fracture with instability; type 4D, central acetabular fracture/dislocation.