- w/ application of severe AP force, hemipelvis rotates externally until posterior iliac wing contacts posteior sacrum;
- continued force rips posterior SI ligaments, completely dissconecting hemipelvis from the sacrum;
- APC III have highest rate of assoc injury, including retroperitoneal bleeding;
- by definition then, an APC III injury shows destruction of all the ligamentous constraints connecting the involved side of the
hemipelvis to the axial skeleton and the opposite hemipelvis;
- these types of fractures are associated with vascular injury;
- 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);
- Radiology:
- Push-Pull Views:
- used to evaluate dynamic displacement of the pelvis;
- these views are obtained as in Outlet view w/ examiner pushing on the femur for one view and pulling on it for other;
- references: Radiological analysis, operative management and functional outcome of open book pelvic lesions: a 13-year cohort study.
- Anterior Fixation Methods:
- anterior fixation alone is indicated for type II fractures, where as type III require anterior fixation along with posterior fixation;
- treatment options:
- Orthomed pelvic reduction clamps (temporary for reduction of pelvic volume)
- External Fixation:
- indicated for SI diastasis or pubic ramus frx which cannot be treated by open reduction or screw fixation;
- such as may occur w/ suprapubic cystostomy tube or open frx;
- Open Reduction and Plate Fixation:
- types of anterior plates
- indicated for pubic diastasis greater than 2.5 cm;
- Retrograde Medullary Superior Ramus Screw:
- indicated for superior ramus fractures which occur along w/ an ustable posterior injury
Pelvic fracture in multiple trauma: classification by mechanism is key to pattern of organ injury, resuscitative requirements, and outcome.