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Wheeless' Textbook of Orthopaedics

Classification of Anterior Posterior Compression Injuries


- Seee: Anterior Pelvic Injuries

- Discussion:
    - symphyseal diastasis and/or longitudinal rami fractures;
    - these injuries result from relatively anterior or posterior forces applied to the anterior or posterior superior iliac spine areas;
    - this gives rise to forces that tend to disrupt anterior pelvis, either by fracturing pubic rami or by rupturing ligaments of symphysis pubis;
    - classification:
         - APC-I
                - slight widening of pubic symphysis and/or anterior SI joint
                - stretched but intact anterior SI, sacrotuberous, & sacrospinous ligaments,intact posterior SI ligaments;
         - APC II
                - widened anterior SI joint; disrupted anterior SI, sacrotuberous, and sacrospinous ligaments, intact posterior SI ligaments;
                - continued AP forces tend to cause splaying of anterior pelvis, w/ external rotation of iliac wings swinging open at posterior aspect of SI joints resulting in a type II frx;
         - APC III
                - complete SI joint disruption with lateral displacement;
                - disrupted anterior SI , sacrotuberous, and sacrospinous lig and disrupted posterior SI ligaments;
                - injuries seen w/ the APC type III fracture is associated with the greatest 24-hour fluid requirements
         - AO type b1 (open book injury - external rotation);
                - injury is caused by an external rotational force which disrupts the symphysis pubis and causes the pelvis to open like a book;
                - hemipelvis is unstable in external rotation, the end point is reached when posterior superior iliac spine abuts against sacrum;
                - in this particular injury, posterior ligamentous structures remain intact so no vertical instability is possible;
                - lesion may be unilateral or bilateral;
                - if symphysis pubis is open < 2.5 cm, only symphysis is disrupted but not sacrospinous or anterior sacroiliac ligaments;
                - if the symphysis is open more than 2.5 cm there is disruption of the sacrospinous and anterior sacroiliac ligaments;
    - stability:
         - depends on integrity of various ligaments involved;
         - division of symphysis allows approx 2.5 cm of diastasis of symphysis;
         - additional division of anterior sacroiliac, sacrospinous, & sacrotuberous ligaments allows further diastasis (causing type II)
         - complete instability is not achieved until all of sacroiliac ligaments are disrupted (type III);

- Other Considerations:
    - diastases: (45%) (may be associated w/ SI ligaments or Malgaigne frx);
             - three types of diastases:
                     - open-book type;
                     - vertical-displacement type;
                     - posterior-displacement type;
    - straddle fractures;
             - straddle frxs (free-floating symphyses) accounted for 20 % of frx;
             - > 50% pts had bladder or urethra injury;
             - nondisplaced frx require only symptomatic care;
             - displaced frx, esp w/ urinary tract injury, require stabilization;
             - w/ free-floating symphysis, contraction of abdominals such as that which occurs with coughing produces pain, frx displacement, and soft tissue injury;
             - presence of straddle frx should alert for possibility of intr-abdominal or urethral injury;
                      - 33% of pts w/ straddle fractures required laparotomy;
    - intraarticular fractures: (5%)
             - mechanism of frx was same in these injuries, consisting of lateral compressive force against pelvis w/ hyperextension or hyper-abduction of the thigh;
             - intraarticular frx present no problem in terms of management and usually healed with synostosis of the symphysis;
             - overlapping pubic bones are assoc w/ urethral injuries, & residual disability accompanies failure of reduction;
             - overlapping dislocations;
             - combination fracture-dislocations;



- Management:
    - this injury is stabilized by reducing anterior symphyseal diastasis;
    - external pelvic fixator:
           - this maneuver uses intact posterior SI ligaments as tension band and is best accomplished w/ external pelvic fixator;
    - hemmorhage:
           - hemmorhage is directly linked to close proximity of internal iliac vessels & anterior SI ligaments,  which are disrupted in open book injuries;http://www.wheelessonline.com/edit_page.php?page=37521
           - angiographic embolization is indicated only if pt is hemodynamically unstable after pelvic reduction;
           - closed techniques:
                   - pelvic sling is applied around the greater trochanters and the symphysis pubis
                   - tensioned to 180 N;
                   - references:
                         - Noninvasive reduction of open-book pelvic fractures by circumferential compression.
                         - Emergent Management of Pelvic Ring Fractures with Use of Circumferential Compression.
                         - Unstable pelvic ring disruptions in unstable patients.
                         - A rational approach to pelvic trauma. Resuscitation and early definitive stabilization.
                         - Prehospital stabilization of pelvic dislocations: a new strap belt to provide temporary hemodynamic stabilization.
                         - Stabilization of pelvic ring disruptions with a circumferential sheet.
                         - The antishock pelvic clamp.
                         - Pressure-volume characteristics of the intact and disrupted pelvic retroperitoneum.



The long-term results of nonoperatively treated major pelvic disruptions.

[Our results of surgical management of unstable pelvic ring injuries]



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, September 6, 2012 1:01 pm