History
Basic mechanism of significant blunt trauma should prompt consideration of a pelvic fracture. Helpful historical features include inability to ambulate at the scene, bowel or bladder incontinence, and objective numbness or weakness of lower extremities.
Pelvic apophyseal avulsion fractures generally occur in young athletes, and are commonly associated with sports involving rapid acceleration and deceleration, such as soccer, football, gymnastics, basketball, and baseball. [21]
Physical
In patients who are awake and alert, the presence of pelvic pain or tenderness to palpation has high sensitivity and specificity for the diagnosis of pelvic fracture: 74% and 97%, respectively. However, in patients who are not awake and alert to express pain and tenderness, physical exam is less useful. Palpation of a pelvic deformity has a sensitivity of 30% for pelvic fractures and 55% for unstable pelvic fractures. Palpating an unstable pelvic ring has a sensitivity of only 8%, but specificity of 99%. Thus, physical exam should not be used to rule out a pelvic fracture in unconscious patients, but it can nearly definitively rule it in. [10] The clinical exam is useful in patients who are awake and alert, even with elevated ethanol levels, as long as their GCS is 14 or higher. [11] Finally, extensive manipulation of a fractured pelvis can increase the patient's discomfort and potentially increase bleeding.
Other signs that may suggest a pelvic fracture include hematuria; a hematoma over the ipsilateral flank, inguinal ligament, proximal thigh, or in the perineum; neurovascular deficits in the lower extremities; or rectal bleeding. Digital rectal examination has a very low sensitivity for diagnosing pelvic fractures. In fact, in one study assessing the utility of routine digital rectal examinations to diagnose injury in 1401 trauma patients, the rectal examination missed 100% of the 67 pelvic fractures. [37]
Vaginal bleeding or palpable fracture line on careful bimanual examination suggests pelvic fracture in females.
Instability on hip adduction and pain on hip motion suggests an acetabular fracture, with or without an associated hip fracture.
The overall incidence of genitourinary injury associated with pelvic fracture is around 4.6% and is overall more common in men. Men with pelvic fractures are 10 times more likely to sustain urethral injuries. [25] Signs of urethral injury in males may include a scrotal hematoma and blood at the urethral meatus. Assessment for a high-riding or boggy prostate on digital rectal examination has been shown to be unreliable. [38]
Pelvic apophyseal avulsion fractures generally present with acute onset of localized pain that is exacerbated by passive or active stretching of the involved muscle. Patients will attempt to assume a position that incurs the least tension on the affected muscle. [21]
Causes
Adults with significant pelvic fracture:
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Motor vehicle crash (50-60%)
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Motorcycle crash (10-20%)
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Pedestrian versus car (10-20%)
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Falls (8-10%)
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Crush (3-6%)
Children:
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Pedestrian versus car (60-80%)
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Motor vehicle crash (20-30%)
Complications
Complications of pelvic fracture include the following:
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The incidence of deep venous thrombosis is increased.
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Continued bleeding from fracture or injury to pelvic vasculature may occur.
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GU problems from bladder, urethral, prostate, or vaginal injuries: The incidence of urethral injuries varies by the type of pelvic fracture. Sexual dysfunction may develop.
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Infections from disruption of bowel or urinary system may develop.
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Chronic pelvic pain, more so if the sacroiliac joints are involved, may occur. [39]
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Anterior-posterior (AP) compression pelvic fracture.
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Vertical shear (VS) fracture pattern.
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Anteroposterior (AP) compression injury as seen on an AP radiograph of the pelvis. Characteristic features of an AP compression injury include symphyseal and sacroiliac joint diastasis. In this patient, the pubic symphysis and right sacroiliac joint are widened.
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Windswept pelvis (lateral compression injury) as seen on a pelvic CT scan. The patient sustained a left lateral compression injury with internal rotation of the left hemipelvis and a characteristic sacral buckle fracture. Note the concomitant left sacroiliac joint diastasis. The lateral force vector continued across the pelvis to produce external rotation of the right hemipelvis and diastasis of the right sacroiliac joint. The combination of injuries resulted in a windswept pelvis.
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Pelvic apophyseal avulsion fracture of the ischial tuberosity due to contraction of the hamstring muscles. Courtesy of Wikipedia (https://de.wikipedia.org/wiki/Apophyse).
Tables
| Type A | Sacroiliac complex is intact. Stable fractures of the pelvic ring that can be managed nonoperatively. |
| Type B | Rotationally unstable, vertically stable. Caused by external or internal rotation forces causing partial disruption of the posterior sacroiliac complex. |
| Type C | Rotationally and vertically unstable. Complete disruption of the posterior sacroiliac complex. |
| Lateral Compression | |
|---|---|
| Grade I | Sacral compression fracture on side of impact. |
| Grade II | Sacral compression fracture with associated posterior iliac fracture on side of impact. |
| Grade III | Type I or II plus associated contralateral sacroiliac joint injury. |
| Anterior-Posterior Compression | |
| Grade I | Mild widening of the pubic symphysis with intact posterior pelvic ring ligaments and sacroiliac ligaments. |
| Grade II | Diastasis of pubic symphysis with associated anterior sacroiliac joint widening with intact posterior sacroiliac joint ligaments. |
| Grade III | Diastasis of pubic symphysis with complete disruption of sacroiliac joint and posterior pelvic ring ligaments. |
| Vertical Shear | Displacement of the hemipelvis superiorly or posteriorly involving diastasis of the pubic symphysis, rami fractures, displacement of the sacroiliac joint, and/or fractures of the iliac wing or sacrum. |
| Combined Mechanism | Because of the high-energy nature of these injuries, the mechanisms are often combined and difficult to determine and categorize. |
