Injury to the pelvis occurs in approximately 8-9% percent of what is termed blunt trauma: falls, motor vehicle crashes (cars and motorcycles), bicycle wrecks, and pedestrians being struck by moving vehicles. 

The pelvis has many parts.  Fortunately, a majority of pelvis fractures are minor, and while painful, do not require any surgery.  The anatomy of the pelvis is diagrammed below: 

The pelvis is like a pretzel, it is impossible to break the pelvis in one location without suffering a break (fracture) in a second location.  Knowing this, when one fracture is seen, careful inspection is undertaken to look for a second fracture.  The pelvis is divided into several sections, and the need for surgery depends upon which section is injured. Also, certain types of pelvis injury are life-threatening and need urgent attention.

Superior and Inferior Pubic Rami:

This is the bottom-most portion of the pelvis and comprises the bones we sit on.  The two sets of rami are essentially two rings attached in the middle at the pubis symphysis.  Fractures in these locations, while painful, generally do not require surgery.  Usually, within 24-48 hours, patients are encouraged to be up and walking.  Often, a walker is used for stability, until pain has diminished. 

Acetabulum:

Acetabulum fractures, or fracture of the “socket” of the hip are more problematic.  The integrity of this socket is what keeps the ball of the femur in place.  Breaks in this area, depending upon location and severity, may require surgery to stabilize the joint.  Dislocations can also occur.  Manipulation in the emergency department or the operating room allows for “relocation” of the joint.  If there are no associated fractures, further surgery is usually not warranted.  Of importance, the blood supply to the “ball joint” of the femur is in this location, so early “relocation” is important. 

Iliac Wing:

Fractures of the iliac wing, while painful, generally do not require surgery.

Sacrum:

The iliac wings of the pelvis attach to the sacrum, the lowest portion of the spine.  Fractures through the sacrum, or injury that produces a widening where the iliac wings attach may result in an “unstable” pelvis – that is, surgical intervention may be required to allow for appropriate healing.  Surgery in this area, in part, depends on the status of the remainder of the pelvis bones. 

Life-Threatening Injuries:

These injuries are considered life-threatening due to the potential for damage to surrounding blood vessels and nerves.  These are described below. 

Open-book pelvis injury:  In this instance, the front of the pelvis opens like a book.  This injury results in tears of the strong pelvic ligaments that hold the pelvis bones together.  Large arteries pass near these ligaments and can get torn resulting in massive blood loss.  Also, pelvis veins can bleed in this location. This requires an emergency intervention to stop the blood loss.

Vertical shear pelvis injury:  This is when one half of the pelvis shifts upwards.  Like an open book, tears in the pelvic ligaments, as well as in the sacral ligaments can result in massive blood loss. 

Lateral crush injury:  Like the other two fractures, half of the pelvis is crushed either inward or outward, again, resulting in damage to surrounding vessels and structures. 

Hip Fractures

Hip fractures occur to the top portion of the femur and per se, are not considered a pelvis fracture, thus are not included in this discussion.

J Dunn

April 30, 2012