Ortho Oracle - orthopaedic operative atlas
Home » Bones » Pelvic » APC II


- Discussion:
    - involves tearing of both anterior SI ligaments of floor of pelvis (sacrotuberous and sacrospinous);
    - involves a widened anterior SI joint  & injury to anterior ring (usually a symphysis diastasis) best seen on the Inlet view;
    - may be bilateral or unilateral;
    - this is a true open book injuries w/ splaying of anterior pelvis:
           - anterior constraint (anterior bony ring & sacrospinous, sacrotuberous, & anterior SI ligaments) are torn, leaving intact only the posterior SI ligaments (which serve as the binding of the book);

- Assessment of Stability:

    - isolated division of symphysis pubis allows approx 2.5 cm of diastasis of symphysis pubis;
    - further division of anterior sacroiliac, sacrospinous, & sacrotuberous ligaments causes further instability (APC II), but complete instability does not occur until all of sacroiliac ligaments are disrupted (Type III);

- Sequelae:

    - this type of injury leaves the pelvis unstable to external rotation;
    - may produce significant neural and arterial complications;

- Management:

    - External Fixation:
            - consider anterior external frame;
            - pins should remain in place for approx 6-8 weeks;
    - Plate Fixation