1 Introduction—epidemiology

Injuries to the pelvic ring should always be expected in those suffering high-energy trauma. In traffic-related injuries, pelvic fractures occur in up to 42% of individuals and patients presenting with a pelvic fracture and hemodynamic instability have an in-hospital mortality of up to 34%. Thus, a pelvic injury is an indicator of major trauma and associated injuries must be actively excluded.

Due to the close proximity of osteoligamentous structures to pelvic organs, neurovascular, hollow-visceral, and urogenital structures may lead to a wide range of severe complications and late sequelae if not diagnosed and treated early.

Urethral injuries are seen at a rate of 1 per million population and require expert management in specialized centers. The psychosexual impact of pelvic injuries is poorly addressed.

Pelvic injuries form about 3% of all fractures with 19–37 injuries per 100,000 population per year. They have a bimodal distribution, with peaks occurring in people aged 15–30 years and 50–70 years. In the younger population, most pelvic fractures occur in men with high-energy trauma, while women suffer more pelvic injuries with increasing age from simple falls.

The mechanism of injury reflects the diverse population groups, with the younger population more likely to sustain high-energy, unstable injuries from motor vehicle injuries and falls from height. Patients with osteoporosis more commonly sustain stable fractures from low-energy falls from standing. But experience in the UK highlights an increasing group of active elderly patients sustaining severe, high-energy injuries. Death from hemorrhage can still occur from what appears to be a simple pubic ramus fracture.

Pelvic fractures are often complex injuries and early computed tomographic (CT) evaluation should be the goal. The initial assessment and resuscitation of such patients should follow advanced trauma and life support (ATLS) guidelines including a search for any sources of bleeding and hemodynamic stabilization. Ideally such patients will have been triaged to a major trauma center by the first responder. If presenting to a leve II or level III trauma center, the patient should be stabilized in the emergency department (ED) and plans to transfer safely but rapidly to a major trauma center should be made—ideally straight from ED to ED.

The pelvis should be protected, just as the cervical spine is collared. A pelvic binder should be applied to splint the pelvis, reducing movement and pain. If possible, it is applied prehospital and it must be placed correctly, over the greater trochanters with internal rotation of both knees. Clinical examination of the pelvis with bimanual compression of the iliac wings has poor sensitivity and may disrupt the initial clot formed at the fracture site and reactivate hemorrhage. This examination is no longer recommended.

Most signs of pelvic injuries can be identified by inspection of the patient. One of the lower limbs may be held in an abnormal position. Bruising around the flanks may be a sign of a retroperitoneal hematoma, and bruising may also be seen around the scrotum or thigh (Destot sign), perineum, or gluteal folds. Blood seen at the urethral meatus or hematuria may be indicative of a pelvic fracture with combined urethral injury, a severe injury requiring expert management. On palpation of the abdomen, tenderness in the suprapubic region may indicate disruption of the pubic symphysis or pubic rami. Other examination findings suggestive of a pelvic fracture are hip pain and tenderness over the sacrum. Associated soft-tissue injuries in the rectum and vagina must also be identified.

Emergency decisions can be based on an AP pelvis x-ray, whereas the detailed classification is assigned after additional oblique projections (45° inlet and outlet views, Fig 6.4-1 ) and/or a CT examination. In all situations which are unclear or where a lesion within the posterior pelvic ring is suspected or diagnosed, CT examination is the diagnostic gold standard. Additional diagnostic techniques, such as ultrasound or cystourethrogram, must be included if a specific lesion is suspected.

2 Anatomy

2.1 Osteoligamentous structure

The pelvis has a stiff osteoligamentous ring structure with the pelvic joints (sacroiliac joints and pubic symphysis) allowing limited movement under load. It is a true ring structure; hence if the ring is broken and displaced in one area, there must be an injury in another part of the ring. By far the greatest proportion of load goes through the posterior ring structures, giving them the key role when pelvic stability is assessed. The pelvic bones themselves have no inherent stability and therefore the integrity of the ligamentous structures is crucial to the preservation or loss of stability ( Fig 6.4-2 ).

3 Classification

The two most common classification systems used for pelvic ring fractures are (1) the Tile and AO/OTA Fracture and Dislocation Classification, and (2) the Young-Burgess classification [1–5].

The basis of the Young-Burgess system is an understanding of the direction of force causing the resulting injury. The three main causative vectors are lateral compression (LC), anterior-posterior compression (APC), and vertical shear (VS) ( Table 6.4-1 ). Once the direction of the causative force vector is understood, the relevant bony and soft-tissue anatomy disruption can be predicted, as well as likely associated injuries to other body systems and sources of bleeding.

The key to understanding the Young-Burgess classification is that the LC category represents anatomically different areas. As one works through the classification: 1 = sacrum, 2 = wing, and 3 = bilateral posterior injuries. Each category has a wide spectrum of injury from benign to devastating. The AP category is the same injury but sequentially worse in severity through the three types.

The Young-Burgess classification has the advantage over the Tile classification of being useful in the ED. In general, a patient who appears to be bleeding with an AP injury will most likely be bleeding from the pelvis causing hemodynamic instability. A patient with an LC injury that is unstable will most likely be bleeding from associated head, chest, or abdominal injuries but not as much from LC injury. Understanding this allows early appropriate focus.

A patient suffering an impact from the side can be predicted to have an LC injury where the force compresses the sacrum and pubic rami resulting in a compressive sacral fracture and pubic rami fractures (LC1). With higher force, the sacrum acts as a pivot around which the hemipelvis rotates inward, resulting in a fracture of the iliac wing (LC2). With even greater force, the compressive force becomes a distracting force on the contralateral hemipelvis, externally rotating that side resulting in an opening of the contralateral sacroiliac (SI) joint and symphyseal disruption (LC3).

An APC of the pelvis results in external rotatory forces being applied, disrupting the pubic symphysis. A low force will diastase the symphysis but leaves the sacroiliac ligaments intact (APC1). A continued force will open the pelvis to such an extent that the anterior sacroiliac ligaments rupture (AP2), followed by complete rupture of the posterior sacroiliac ligaments (AP3). The APC3 injuries are usually considered to be both vertically and rotationally unstable.

A significant vertically directed force will result in rupture of all ligamentous structures of the sacroiliac complex, pelvic floor, and pubic symphysis resulting in a vertical shear injury. The hemipelvis will be displaced vertically, with dislocation of the sacroiliac joint or a vertical sacral fracture, combined with pubic symphysis disruptions or fractures to the pubic rami. A final category, combined mechanism of injury, represents patients who have received more than one vector—a pedestrian stuck by a car, and then receiving a second force when landing, for example. The category is not intended for ring injuries that are initially difficult to classify.

The Tile classification of pelvic injuries is based on the AO/OTA Fracture and Dislocation Classification ( Fig 6.4-3 , Table 6.4-2 ) and comes from the evaluation of the mechanism of injury and the resulting stability/instability of the pelvic ring. By extending the three basic fracture types A, B, and C by groups, subgroups, and specific modifiers, every injury and combination of injuries can be classified (see chapter 1.4).

The classification represents three categories of increasing severity. It classifies injuries by the pelvic ring′s ability to withstand vertical or rotational physiological forces as a result of the fracture: its “stability”. In this classification, the posterior pelvis is located posterior to the acetabulum and the anterior arch anterior to it. Type A fractures, of which there is not an equivalent in the Young-Burgess classification, are stable; hence, the pelvic ring cannot be displaced by a physiological force. Type B fractures are rotationally unstable but vertically stable, while type C fractures are vertically and rotationally unstable.

Both of these classification systems have been found to predict the severity of associated injuries (such as head, chest, or abdominal injuries), and mortality in patients with pelvic fractures but only if divided into stable (type A and LC1) and unstable (all others) injuries. With regard to blood transfusion requirements, LC3, APC2, and APC3 fractures have higher transfusion requirements than LC1, APC1, and VS fractures.

4 Primary evaluation and decision making

The primary goals in the assessment of pelvic injuries are:

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  Accurate placement of a pelvic binder

  
  
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  Establishing whether the pelvis is the primary source of hemorrhage in a hemodynamically unstable patient

  
  
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  Diagnosing associated open wounds, urogenital or organ injuries

A patient with a pelvic fracture will ideally be managed in a trauma center by a team led by an experienced trauma team surgeon [6]. Recent evidence indicates a clear survival benefit of trauma center management. The primary management is the same for any polytrauma patient as described in chapter 4.1 and will include permissive hypotension, the administration of tranexamic acid and blood products as part of a massive transfusion protocol (possibly guided by point-of-care coagulation tests), and evaluation of the response, including acidosis and blood lactate.

Pelvic fractures are associated with significant mortality, with hemorrhage the major cause of death from unstable pelvic fractures. In the acute stage, simple emergency measures, such as internally rotating the hips and strapping the ankles together, are beneficial. Increasingly, pelvic binders are applied prehospital.

4.1 Placement of a pelvic binder

A pelvic binder is a noninvasive piece of material applied circumferentially around a patient′s greater trochanters and manually tightened ( Fig 6.4-4a ). Pelvic binders function to splint the pelvic ring, decrease overall pelvic volume, and reduce bleeding from fractures. In addition, splinting of the pelvic ring tamponades bleeding bone and protects the initial clot from disruption. The initial clot is the most effective clot. For the most effective stabilization, binders should be placed at the level of the greater trochanters with internal rotation of lower limb and tensioned according to manufacturer guidance (which differ according to each brand) to compress and splint the pelvis. A simple sheet is as effective initially but is more likely to become loose ( Fig 6.4-4b ). Binders and sheets are quick and simple to apply and with good nursing can remain in place for 24 hours without the development of pressure effects on the skin.

Cadaveric and in vivo studies have shown the successful reduction of APC pelvic fractures using binders. Pelvic binders have been shown to reduce transfusion requirements compared with external fixation, improve hemodynamics in trauma patients, while not compromising mechanical stability. The use of a pelvic binder for an LC fracture is open to question, with little evidence as to the potential benefits or risks. The binder may stabilize the pelvis, but risks displacing the LC injury. It is good practice to apply a binder in any suspected pelvic fracture, and loosen it once an LC1 or LC2 fracture is diagnosed, leaving it around the patient as a reminder of the presence of a fracture while awaiting surgery.

External fixation is not as commonly used now but can effectively close an open-book pelvis, provided the posterior complex is intact, and gives good anterior stability. Anterior pins can be placed along the superior iliac crest above the anterior superior iliac spine (ASIS) or between the ASIS and the anterior inferior iliac spine.

In theory, external fixators have the advantage of providing temporary or definitive stabilization of pelvic fractures and allow abdominal surgery when necessary. However, the pelvic binder in the correct position on the trochanters does not impede laparotomy.

The use of pelvic binders has effectively removed the need for external fixators in the emergent period. If the application of a correctly positioned and tensioned binder fails to improve the hemodynamic status of a patient, it is unlikely an external fixator will improve matters. It must not be forgotten that there may be a vertical component to the pelvic injury and vertical traction through application of skin traction or a skeletal pin may be necessary to attain a reduced pelvic injury along with use of the binder. At this point, further interventions are required to control hemorrhage.

It is essential that early pelvic imaging is obtained to “clear the pelvis”. A single AP image has a high sensitivity and specificity for clinically significant pelvic fracture. When resuscitating a patient with multiple injuries, a pelvic x-ray should be obtained at the same time as or immediately after that of the chest, if immediate CT scanning is not available. Clinical examination of the pelvis should concentrate on looking for bruising and wounds, especially of the perineum. Clinical tests of mechanical stability should not be performed in the ED. It is a test that has poor sensitivity, can be painful for the patient, and may disrupt stable blood clots that have already formed. Examination of the pelvis in this way should be restricted to examination under anesthetic in the operating room as part of further evaluation of the injury by an expert [7, 8].

If a normal AP pelvic x-ray or CT imaging has been obtained in a binder, and there is any clinical suspicion of pelvic injury, a subsequent AP x-ray should be obtained with the binder released to rule out an AP compression injury that had been perfectly reduced by the binder.

“Log rolling” of the patient should not be performed until after imaging of the pelvis has been reviewed. Rolling a patient with an unstable pelvic fracture will result in considerable movement of the fracture and risks causing further bleeding. This secondary hemorrhage can be difficult to control, as the patient may have developed a coagulopathy by this stage.

Blast injuries may result in pelvic fractures combined with penetrating shrapnel wounds to the back.

Related posts:

6.1.1 Scapula 6.2.1 Humerus, proximal 6.3.3 Distal radius and wrist 6.8.2 Tibia, shaft 6.6.3 Femur, distal Section 6 Specific fractures

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