Introduction

Pelvic fractures are encountered in approximately 10% of patients who experience blunt trauma. These are most often young patients with high overall injury severity scores. Life-threatening bleeding occurs in 1% to 4% of all pelvic trauma cases, while present mortality rates are as high as 60%. Bleeding from a pelvic injury occurs from several sources, including fractured bone ends, arteries, veins, and pelvic viscera. These fractures are often compounded by the loss of the natural tamponade effect within the pelvis as a result of pelvic ring instability and disruption of the pelvic floor. One of the key strategies employed in the early management of pelvic fractures is the application of a pelvic circumferential compression device, more commonly referred to as a pelvic binder. This device recreates the tamponade effect by reducing pelvic volume and increasing intrapelvic pressure to facilitate clot formation. When used early in managing pelvic fractures, pelvic binders have been demonstrated to reduce transfusion requirements.[1][2][3][4]

The use of pelvic binders has been incorporated into teaching prehospital and emergency room management of trauma and is integral to Advanced Trauma Life Support (ATLS). The rate of detection of pelvic fractures by clinical examination is often poor. Therefore, the ATLS guidelines adopt a low threshold for their use where potential pelvic injury may be encountered.[5] Educating practitioners about the correct application of pelvic binders is challenging because evidence from major trauma centers frequently demonstrates improper application.[6][7]

Anatomy and Physiology

Up to 85% of bleeding following pelvic trauma is venous in origin and may be catastrophic as the pelvic cavity can accommodate the entire circulating volume. Bleeding most commonly follows injury to the presacral plexus and prevesical veins. Arterial bleeding occurs in only 15% to 20% of pelvic trauma, most commonly from branches of the internal iliac artery. A third non-vascular source of bleeding is the fractured bone ends following their disruption.[2]

The pelvic ring consists of the sacrum and two innominate bones. Each innominate bone is divided into the ischium, ilium, and pubis. The two innominate bones are joined anteriorly at the pubic symphysis and posteriorly to the sacrum via the sacroiliac joints. The stability of the pelvic ring is predominantly provided by the posterior pelvic ring, specifically the anterior, posterior, and intraosseous sacroiliac ligaments. Additional ligaments contributing to the stability of the pelvic ring include the sacrotuberous ligaments, sacrospinous ligaments, iliolumbar ligaments, and lateral lumbosacral ligaments.[8][9]

The internal iliac artery is a division of the common iliac artery. It enters the true pelvis at the pelvic brim and divides into its anterior and posterior divisions. The ureter lies anterior to the internal iliac artery and posterior to the internal iliac vein. Direct injury to the internal iliac artery is uncommon but fatal.[10]

Branches of the posterior division of the iliac artery are at high risk due to their proximity to the posterior pelvic ring. The superior gluteal artery courses across the anterior part of the sacroiliac joint before passing through the greater sciatic notch. This is a common site for fracture displacement, particularly in lateral compression-type injuries. Injury to the superior gluteal artery is a common cause of arterial bleeding. The lateral sacral artery descends lateral to the sacral foramina on the ventral surface of the sacrum, and the iliolumbar artery ascends in a similar plane. Both of these structures are at risk of bleeding with displaced fractures of the sacrum.

The anterior division of the iliac artery provides blood supply to the viscera of the pelvis. The internal pudendal and inferior gluteal arteries pass anterior to the sacral venous plexus, exiting the pelvis through the greater sciatic notch close to the ischial spine. A displaced fracture may tear both. The obturator artery runs along the side wall of the pelvis, exiting through the superolateral obturator foramen. In 80% of cases, a connection exists between the obturator artery and the external iliac artery, known as the corona mortis. Both these vessels are at risk of displaced fractures of the superior pubic pubic ramus.[11]

The pelvic viscera sit upon a plexus of veins that drain into veins named similarly to their arterial counterparts. These veins drain into the internal and external iliac veins. The presacral plexus is an anastomosis between the median and lateral sacral veins and is situated within the fascia on the anterior aspect of the sacrum. This position makes it vulnerable to injury with displaced fractures of the posterior pelvic ring.[12]

Indications

Prehospital diagnosis of a pelvic fracture can be difficult. Often, an absence of external signs of pelvic injury exists, and patients frequently have sustained distracting injuries. Even when assessment is performed by a specialist trained in advanced helicopter emergency medical service (HEMS), an unstable pelvic ring injury is correctly identified in only 47% of cases. A pelvic binder should be placed in all trauma patients presenting with hemodynamic instability and pelvic pain or trauma cases with a mechanism that is suspicious for significant pelvic injury. Historical techniques to assess pelvic stability, such as "springing the pelvis," are discouraged because they have low sensitivity and could potentially disrupt early clot formation.[13][14][15]

Contraindications

The application of pelvic binders in the prehospital setting without the use of diagnostic imaging has generated criticism. There is a lack of research into whether they are overused. The application of pelvic compression devices is contraindicated for injuries other than the pelvic ring (eg, femur or hip fractures). Assessment of a pelvic ring injury or an isolated hip fracture in the prehospital setting is unreliable. A pelvic binder should be applied to all patients with pelvic injury concerns.[16]

Some studies suggest that pelvic binders do more harm than good when used in lateral compression fractures due to the pattern of fracture and their unstable nature. However, as these injuries cannot be identified easily without imaging, trauma protocols have continued to recommend the use of pelvic binders.[17][18]

Another important consideration is the risk of soft tissue compromise from prolonged compression or over-tightening of the pelvic binder. Skin necrosis and ulceration can occur within 3 hours of application. Binders should be removed within 24 hours of application.[1] Some studies have also proposed that polytrauma patients have a higher risk of soft tissue breakdown due to the release of systemic factors following injury.[19][20]

Technique or Treatment

Commercial pelvic compression devices are easy to use, can be applied quickly, and require minimal training. The most well-recognized brands include the SAM Sling, the T-POD splint, the Prometheus pelvic splint, and the field expedient pelvic splint. Prehospital trauma teams commonly carry these devices. Should these be unavailable, circumferential sheets or wraps can be utilized to try and obtain a similar effect. A recent assessment of proprietary and nonproprietary pelvic binders demonstrated that the T-POD sling and the SAM pelvic sling were the highest-performing of the available splints and maintained the highest tension. Clinical studies showing a significant benefit of one device compared to another have not been published.[21]

Pelvic binders must be positioned correctly to achieve adequate stability and hemorrhage control. The binder should be centered over the greater trochanters of the femur. Several biomechanical studies illustrate that this position allows near-anatomical reduction of an unstable fracture under less tension.[22][23] Cephalad positioning over the iliac crests can lead to overtightening during efforts to control bleeding and increases the risk of soft tissue compromise.[6]

The method of application may explain why pelvic binders are frequently malpositioned. Studies suggest that placing the device under the lumbar spine before sliding caudally results in too cephalad a position, often resting over the iliac crests. Instead, the binder should be placed under the knees without significant movement of the legs. Clothing over the hip and thigh regions should be removed if possible, as these can contribute to accelerated pressure damage. The knees should be brought together, and the limbs internally rotated before the binder is placed at the level of the greater trochanters and tightened according to the manufacturer's instruction.[22] The patient's knees and ankles may also be bound together to assist internal rotation at the hips.[24] Where a coexisting femoral fracture results in the shortening of the limb, a figure-of-eight bandage can be tied around the foot and ankle to splint the pelvis and the femur. 

Clinical Significance

Computerized tomography (CT) scans are helpful in the detection of pelvic fractures where a plain radiograph is insufficient.[25] Following stabilization in the emergency department, trauma patients routinely undergo CT imaging as part of their workup. Imaging is usually conducted with the pelvic binder placed to avoid disrupting a potential blood clot that could lead to further bleeding.[26] Practitioners must be aware that the use of pelvic binders can reduce a pelvic fracture but can also mask signs of a fracture. The incidence of missed injuries on initial presentation has been reported as high as 47%.[27] Further examination or imaging (AP radiograph of the pelvis) should be performed with the binder removed to rule out a hidden pelvic fracture.

When utilized early in patients with suspected pelvic trauma, pelvic binders have demonstrated improved morbidity, reduced requirements for blood transfusion, and shorter ICU and hospital stays.[28][29] The supportive effect of pelvic compression devices is largely believed to be provided by the stasis of venous bleeding as they cannot provide adequate compression to tamponade an arterial hemorrhage.[29] Intravenous contrast extravasation (ICE) on CT is a valuable indicator for an active arterial bleed with a sensitivity of up to 84% and a positive predictive value of 80%.[30] Angiography and embolization are effective management options for these patients.[29]

While a hemodynamically unstable patient presenting with a pelvic fracture is not suitable for angiography, the patient will often be a candidate for pelvic packing. The binder is often exchanged for an anterior-based external fixator to pack against.[31] In this situation, there is concern that an anterior external fixator will inadequately control the posterior pelvic ring unless combined with a C-clamp or posterior pelvic fixation. Recent literature suggests that the pelvic binder can be maintained, and pelvic packing performed with the binder continuing to apply circumferential compression, with no differences in transfusion requirement or mortality compared to an external fixator.[32] In another study, a pelvic binder outperformed the use of a C-clamp, resulting in faster hemostasis with reduced mortality.[33]

Pelvic binders provide hemodynamic and mechanical stability to the patient with pelvic injury. They are cost-effective, easy to use, noninvasive, and an essential life-saving tool in trauma management to bridge patient support until the patient can be transferred to a facility that can definitively manage these injuries. Trauma and emergency care practitioners should ensure they are familiar with the accurate application and considerations of using pelvic binders.

Enhancing Healthcare Team Outcomes

Interprofessional teamwork is crucial in trauma management. Prehospital and emergency care practitioners should ensure they are familiar with the accurate application and considerations of using pelvic binders when a pelvic injury is suspected, as the early application of this device can significantly improve outcomes. Trauma and orthopedic specialists should manage the patient once fractures are diagnosed and before the removal of the device can be safely considered. In a persistently unstable patient, the intensivists, interventional radiologists, and the general surgical team provide invaluable input and are essential components of the trauma team.