Despite a relatively mild
winter, most people in central
and southern Illinois will
look forward to the upcoming
warm weather. Unfortunately,
the coming of spring brings
increased incidence of injury
from motorcycle and motor
vehicle crashes, falls and
construction mishaps.
There are two types of
injuries that are commonly
being referred to the Trauma
Center – fracture of the
pelvic ring and fracture of
the acetabulum.
The pelvic ring is made up
of paired innominate, pubic
and ischial bones and the
sacrum. It is joined
posteriorly by the sacroiliac
joints and ligaments and
anteriorly by the pubic
symphysis. On the lateral
surface of the innominate bone
is the acetabulum to which the
ilium, ischium and pubis all
contribute. The cavity
enclosed by the bony pelvis is
divided into two
subcategories. The true (or
lesser) pelvis below the brim
houses the pelvic viscera and
the false greater pelvis above
the brim forms part of the
abdominal cavity. The pelvis
allows transfer of weight from
the vertebral column to the
acetabulum when standing or to
the ischial tuberosity when
sitting.
Pelvic fractures are
divided into two major types
based on the amount of energy
involved – low-energy
fractures, generally resulting
in isolated fractures of
individual bones, and
high-energy fractures,
producing pelvic ring
disruption. Accurate
assessment of the injury
depends not only on the
medical history, physical
exam, diagnostic X-rays and CT
scans, but also on the
knowledge gained from
description of the accident.
Details including the type,
direction and magnitude of
force involved and whether or
not the injury occurred during
a motor vehicle crash,
motorcycle crash, or a fall
are helpful in understanding
the biomechanics of the
injury. These details are
obtained from various sources,
including the patient,
pre-hospital personnel,
witnesses, and deductive
analysis of the clinical
picture. In impact injuries,
it is important to know the
direction of the force
involved (frontal, oblique and
lateral), or whether a
motorcyclist was thrown over
the handlebars and experienced
sudden de-acceleration forces,
or whether the victim landed
in a vertical or lateral
position.
Crush injury is another
mechanism that can occur when
the victim is trapped between
the injurious force in an
unyielding environment, such
as the ground or pavement.
The magnitude, velocity and
duration of the crushing
forces are valuable
information to the orthopaedic
surgeon and the trauma team.
These are important factors
directly affecting the
prognosis.
