Pelvic binders are external devices commonly used to stabilize the pelvic ring in patients with suspected unstable pelvic fracture.
Radiographic features
Most binders have a single metallic buckle, which allows the approximate assessment of their position on pelvic radiographs too. The plastic parts are only visible on CT. Both on plain film and CT the buckle should be positioned approximately at the level of the greater trochanters 1.
Practical points
Pelvic binders prevent further dislocation of fractured bone fragment, thus reducing the risk of further soft tissue trauma (e.g. vessel laceration). By stabilizing the pelvis, these devices facilitate clot formation 2. The binder is typically applied in the pre-hospital setting. It has been shown that a high position above the greater trochanters is the most common form of binder malposition, and it has a negative effect on clinical outcome 1.
Radiologists should be aware of the normal position of pelvic binder, and its presence should be factored into the assessment of bony trauma. These binders can render traumatic symphyseolysis (e.g. open book fractures) or sacroiliac joint injury rather subtle on initial imaging, and their removal can be followed by a rapid increase of the diastasis 2. If discrete signs of injury (small avulsed fragments, hematoma) are present around these structures, it is prudent to perform a focused repeat scan or at least obtain an AP radiograph of the pelvis after removal of the pelvic binder 3.