TY - CHAP M1 - Book, Section TI - Skeletal Trauma: Lower Extremity A1 - Wenokor, Cornelia A1 - Blacksin, Marcia F. A2 - Tehranzadeh, Jamshid Y1 - 2021 N1 - T2 - Basic Musculoskeletal Imaging, 2e AB - The pelvis is formed by the ischium, the pubic bones, and ilium, which through the sacroiliac joints (SI joints) connect to the sacrum. This forms a ring structure. The pubic bones are joined anteriorly by the pubic symphysis and form the anterior ring. The posterior ring is formed by the sacrum, the SI joints, and iliac bones. To disrupt this ring usually requires significant force, which can occur in motor vehicle accidents or similar high-energy trauma. A ring structure usually breaks in more than one place, so it is important to carefully examine the entire ring for a second injury once a fracture is encountered. The second injury does not need to be a fracture; it can be disruption of the SI joints or pubic symphysis (Figure 3-1). SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1181068902 ER -