INTRODUCTION	Section 2 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Background: Pelvic fracture is a disruption of the bony structure of the pelvis. In elderly persons, the most common cause is a fall from a standing position. However, the most significant fractures involve significant forces such as a motor vehicle crash or fall from a significant height.

Pathophysiology: Pelvis consists of the ilium (ie, iliac wings), ischium, and pubis, which form an anatomic ring with the sacrum. Disruption of this ring requires significant energy. Because of the forces involved, pelvic fractures frequently involve injury to organs contained within the bony pelvis. In addition, as the pelvis is supplied with a rich venous plexus as well as major arteries, fractures may produce significant bleeding.

The Young classification system incorporates anatomic mechanism of injury and identifies 4 types of ring disruption. Acetabular fractures, with or without ring disruption, also may occur. Falls in elderly persons may involve fracture (usually of the pubic rami) without disruption of the ring.

Lateral compression (LC) fractures involve transverse fractures of the pubic rami, either ipsilateral or contralateral to a posterior injury.

• Grade I - Associated sacral compression on side of impact

• Grade II - Associated crescent (iliac wing) fracture on side of impact

• Grade III - Associated contralateral "open book" injury

Anterior-posterior compression (APC) fractures involve symphyseal diastasis or longitudinal rami fractures.

• Grade I - Associated widening (slight) of pubic symphysis or of the anterior sacroiliac (SI) joint, while sacrotuberous, sacrospinous, and posterior SI ligaments remain intact

• Grade II - Associated widening of the anterior SI joint caused by disruption of the anterior SI, sacrotuberous, and sacrospinous ligaments, while posterior SI ligaments remain intact

• Grade III (open book) - Complete SI joint disruption with lateral displacement and disrupted anterior SI, sacrotuberous, sacrospinous, and posterior SI ligaments

Vertical shear (VS) involves symphyseal diastasis or vertical displacement anteriorly and posteriorly, which is usually through the SI joint, though occasionally through the iliac wing or sacrum.

Combined mechanical (CM) fractures involve a combination of these injury patterns, with LC/VS the most common.

Acetabular fractures most commonly involve disruption of the acetabular socket when the hip is driven backward in a motor vehicle accident. Occasionally, they will occur in a pedestrian struck by a vehicle moving at a significant rate of speed.

Frequency:

• In the US: Pelvic fractures represent 3% of all skeletal fractures, with single pubic rami and avulsion fractures the most common.

Mortality/Morbidity: Over half of all pelvic fractures occur as a result of minimal-to-moderate trauma, such as a fall from a standing position. Of these, 95% are minor. On the other hand, the more severe pelvic fractures involve significant trauma. Most of this discussion relates to the more severe pelvic fractures.

• The complication rate is significant and is related to injury of underlying organs and bleeding. Because of the tremendous force necessary to cause most unstable pelvic fractures, concomitant severe injuries are common and are associated with high morbidity and mortality rates. In addition, pelvic fractures increase the incidence of pulmonary emboli.

• Overall mortality rate is approximately 10% in adults and 5% in children. Pelvic hemorrhage is the direct cause of death in fewer than half of patients with pelvic fractures who die. Retroperitoneal hemorrhage and secondary infection are the main causes of death in children and adults with pelvic fractures.

• If hypotension is present on arrival to the emergency department, the mortality rate approaches 50%. If the fracture is open, the mortality rate reaches 30%.

Sex:

• Associated genitourinary (GU) injuries vary greatly between men and women and are discussed in other articles. For many years, it was felt that women did not suffer urethral injuries. It is now well known that, while women suffer urethral injuries at a much lower incidence than men, injuries do occur. Women suffer partial lacerations and partial disruption with complete disruption being rare.

Age:

• Age distribution largely matches that of motor vehicle crashes, with car-car injuries more prevalent in adults, especially younger adults, and car-pedestrian injuries more likely to cause injury in children. The other group is the elderly who tend to suffer pubic rami fractures without internal injuries in standing falls.

• Urethral injuries vary widely by age with injuries to the prostatic urethra and bladder neck limited to children. Direct lacerations to the urethra occur only in boys (small prostate) and women.

• The incidence of urethral injuries also varies by the type of pelvic fracture. Straddle fractures associated with sacroiliac diastasis have the highest incidence (odds ratio of 24). Without diastasis, the odd ratio dropped to 3.85. Urethral injuries were essentially nonexistent for fractures not involving the ischiopubic rami.

	CLINICAL	Section 3 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

History:

• Basic mechanism of significant blunt trauma should prompt consideration of a pelvic fracture.

Physical:

• Tenderness over the pelvis that can be appreciated with pelvic springing indicates fracture. Pelvic springing involves applying alternating gentle compression and distortion over the iliac wings.

• Palpable instability of the pelvis on bimanual compression or distraction of the iliac wings also indicates fracture. Be very gentle when pelvic tenderness is appreciated. Do not rock or apply great force until radiographs exclude skeletally unstable pelvic fractures, since an overly aggressive examination can increase hemorrhage unnecessarily. Likewise, examination should be limited to one examiner. Remember that, in the later stages of pregnancy, the pelvic ligaments become stretched and may mimic instability.

• Instability on hip adduction and pain on hip motion suggests an acetabular fracture (in addition to possible hip fracture).

• Signs of urethral injury in males include a high-riding or boggy prostate on rectal exam, scrotal hematoma, or blood at the urethral meatus.

• Vaginal bleeding or palpable fracture line on careful bimanual exam suggests pelvic fracture in females.

• Other signs of pelvic fracture include the following:

• Hematuria

• Rectal bleeding or Earle sign, the appreciation of a large hematoma or palpable fracture line on careful rectal exam

• Destot sign, a hematoma above the inguinal ligament, on the proximal thigh, or over the perineum

• Grey Turner sign, a flank ecchymosis associated with retroperitoneal bleeding

• Roux sign, a bilateral asymmetry in the distances between the greater trochanter and the pubic spine on each side (indicating an overriding fracture of the anterior pelvic ring)

• Neurovascular deficits of the lower extremities

Causes:

• Adults with significant pelvic fracture

• Motor vehicle crash (50-60%)

• Motorcycle crash (10-20%)

• Pedestrian versus car (10-20%)

• Falls (8-10%)

• Crush (3-6%)

• Children

• Pedestrian versus car (60-80%)

• Motor vehicle crash (20-30%)