Pelvic Fractures: External Fixation and C-Clamp

In the field or emergency room setting, emergency care
workers and paramedics trained in advanced trauma life support (ATLS)
often play a critical role. In patients with hemodynamic instability
and a potentially unstable pelvic-ring injury, a single attempt at
reduction should be considered. The responder applies traction to the
unbroken lower extremity on the shortened or deformed side of the
pelvis with manual lateral compression on the iliac wings or greater
trochanters. The knees and ankles should be slightly flexed and
internally rotated and taped together before a noninvasive external
fixation device (wrapped sheet or pelvic binder) is applied (Fig. 37.1).
When done at the scene of an accident, emergent transfer to an
institution capable of treating pelvic trauma may be life saving (7,8).

Hemodynamically unstable patients with pelvic ring
injuries require prompt evaluation and simultaneous aggressive
resuscitation. Initial measures include airway control and aggressive
fluid resuscitation through two 14- to 16-gauge intravenous catheters
in the upper extremities. Physical examination should be directed for
signs of possible mechanical instability of the pelvis. Tell-tale signs
include a history of high-energy trauma from motor vehicle or
motorcycle collisions, falls from a height, or rollover motor-vehicle
collisions. On clinical examination, a shortened and malrotated
extremity, asymmetric iliac spines, swelling or blood on genitals and
perineum, contusion or ecchymosis in the lower abdomen or pelvis
suggest pelvic instability. Gentle, manual, iliac-wing compression from
lateral toward the midline may reveal a mobile hemipelvis and
mechanical instability. A careful neurological examination to assess
for leg sensation and motor function is critical. Vaginal and rectal
digital exams with guaiac test for occult blood and with speculums
(time permitting) help rule out an occult open fracture. If overlooked
and not treated, a fracture hematoma that comes in contact with a
contaminated environment may cause a life-threatening pelvic infection.

The care of a hemodynamically unstable patient with a
displaced pelvic fracture is the responsibility of a multidisciplinary
trauma team that includes a general surgeon, anesthesiologist,
orthopedic surgeon, and invasive radiologist. Trauma protocols are
helpful in evaluating and treating critically ill patients,
establishing priorities, and guiding treatment. Using the algorithm (Fig. 37.2), Ertel et al (9)
were able to save 15 of 20 patients (75%) who presented with multiple
injuries that included unstable pelvic injuries with an average Injury
Severity Score (ISS) of 41.2 ± 15.3. Fifteen patients had massive
hemorrhage (14 were in extremis), and five were in hemorrhagic shock.
Two of them required subdiaphragmatic clamping of the aorta to
stabilize a disastrous hemodynamic situation.

As part of the primary survey, a focused abdominal
sonogram for trauma (FAST) or computed tomography (CT) scan can be used
to determine the presence of free fluid in intraperitoneal,

retroperitoneal,
or pericardial cavities. Arterial blood gas with blood lactate levels
and/or base deficit analyses are good indicators of the hemorrhagic
state and tissue oxygenation (9,10,11).

A chest x-ray is an important part of the trauma work-up
because it can be used to rule out a pneumothorax, hemopneumothorax,
tension pneumothorax, or flail chest. A single

anteroposterior
(AP) radiograph of the pelvis can be used to diagnose a pelvic fracture
correctly in approximately 90% of cases. X-ray signs of instability are
(a) >5-mm displacement of the sacroiliac (SI) joint in any plane
(inlet and outlet views will improve accuracy if circumstances allow),
(b) posterior fracture gap, and (c) avulsions of the transverse process
of fifth lumbar vertebra or avulsion fractures of the sacrospinous
ligament. By definition, a stable pelvic injury can withstand normal
physiologic forces without abnormal deformation. The surgeon should not
routinely manual test for pelvic ring stability because he/she could
dislodge blood clots in a hemodynamically unstable patient. One-time
manual testing, to exclude a situation in which the pelvis had been
unstable but has since been reduced, may be permissible by an
experienced surgeon in cases where the x-rays do not clearly
demonstrate an unstable injury (12,13).

Numerous studies have shown that in patients with
multiple injuries, exsanguination and closed head injury are the main
causes of mortality within the first 24 hours after injury. Damage
control surgeries, for hemorrhage control, decompression of body
cavities such as in the chest and head, and contamination control of
abdominal perforations, as well as devitalized tissue debridement in
the extremities, improve survival. Determination of the patient’s
hemodynamic status and initial response to resuscitation measures allow
placement of the patient in one of three protocol categories that
dictate treatment (see Fig. 37.2).

A subset of multiply injured patients presents in
extremis (i.e., without measurable vital signs). Most of these patients
need a crash laparotomy, thoracotomy, and/or pelvic/abdominal packing
(with or without temporary aortic cross-clamping) to survive (Fig. 37.3).
While awaiting the response of the patient to aggressive resuscitation
therapy, a C-clamp or an anterior, pelvic, external fixator should be
applied. Subsequent, repeated, pelvic/abdominal packing against a firm
stabilized pelvis will be much more effective in tamponading the
bleeding.

If the patient is in a persistent shock category despite
adequate fluid replacement, blood transfusions, and medications over 2
hours, an external fixator or C-clamp should replace a pelvic sheet or
binder. Numerous studies have shown that in patients with unstable
pelvic injuries in which ligaments and fascial planes that support the
pelvic floor have been disrupted, self-tamponade rarely occurs (14). Huittinen and Slätis (15)
have estimated that 80% to 90 % of bleeding following fracture and/or
dislocation comes from disruption of the lumbosacral venous plexus and
fracture bone surfaces and that only 10% have an arterial origin. The
most common technique for stopping the diffuse bleeding (venous or
arterial small vessels) is by tamponade. In patients who require
abdominal exploration, laparotomy

will make the pelvis more unstable because the muscle forces pulling on the iliac wings are diminished (16).
A correctly applied pelvic frame will improve pelvic stability yet not
impede the surgeon’s ability to perform either a supraumbilical
laparotomy (from xiphoid process to symphysis for positive
intra-abdominal fluid) (Fig. 37.4) or
infraumbilical (absent intraperitoneal injury). If a patient with an
unstable pelvic fracture requires a laparotomy for intraperitoneal
injuries, exploration and packing to control retroperitoneal bleeding
may be accomplished as well. Disruption of the soft tissues in the
pelvic floor allows easy, direct access to both sides of sacrum and
bladder for packing (17). Major arteries and
veins (external iliac and femoral) that are damaged also require direct
access and surgical hemostasis. In massive retroperitoneal bleeding
caused by blunt trauma, Ertel et al (9)
recommended that the hematoma in the central zone be explored. This
method also allows assessment of the posterior reduction by direct
manual palpation from inside the pelvis. Bleeding is better controlled
when the bone surfaces or joint are directly opposed (interdigitating)
and compressed. If significant displacement exists, loosening and
adjusting the external fixator, previously applied to improve the
fracture reduction, can be performed. To achieve firm local compression
against the reduced posterior pelvis, the surgeon may need to repeat
the tamponade and look quickly again for any major bleeding sources. If
hemodynamic instability persists despite all measures (including
partially closed distal-abdominal fascia for better support of
packing), then the patient should be transferred for a
contrast-enhanced CT of the abdomen. The study is fast and highly
accurate in determining the presence or absence of ongoing pelvic
hemorrhage (18). Patients with visualized
contrast extravasation, as shown on CT scans, are candidates for
angiography and embolization. Following a similar protocol, the
Hannover Trauma Center was able to reduce mortality rate from 46% to
25% (8,10,15,17,19).

In most North American trauma centers, if evidence of
intra-abdominal free fluid is not found on ultrasound exam or
diagnostic peritoneal lavage (DPL) after noninvasive pelvis
stabilization, angiography and embolization of identifiable bleeding
arteries is usually the next step. Angiography does not address venous
bleeding, is time consuming (which is particularly problematic for a
patient in hemorrhagic shock), and may cause gluteal muscle necrosis.
In addition, only 3% to 5% of patients with unstable pelvis receive
major benefit from the procedure, which requires specialized personnel
and equipment (13,20,21,22).

In a very small subgroup of patients, hemipelvectomy may be life saving (20,23).
High-energy pelvic injuries that are concomitant with a major vessel
injury (e.g., to the common external iliac or femoral artery), which
are characterized by lack of blood flow to the extremity, and a
profound neurologic deficit (and/or intraoperative finding of stretched
and ruptured nerves) cause such persistent hemodynamic instability that
reconstruction attempts are futile.

Open fractures with wounds in the rectal or vaginal vicinity require irrigation and debridement,

a diverting colostomy placed as far as possible from subsequent
surgical approaches to the pelvis, and immediate distal-colon washout.
In addition, a broad spectrum of prophylactic antibiotics should be
given (2,3,4,5,6).

Every male patient with an unstable pelvic injury (with
or without blood on ureteral meatus) requires a retrograde urethrogram
before bladder catheterization. In our experience, a rectal exam cannot
reliably predict the position of the prostate and possible urethral
injury. A urethral injury in this setting is usually treated with a
suprapubic catheter inserted percutaneously or openly during
laparotomy. Patients with hematuria and intact urethra must undergo a
contrast study to rule out a bladder rupture. If no explanation for
hematuria is identified, an abdominal CT and intravenous pyeolography
is used to investigate the upper urogenital tract. In a polytrauma
patient, routine CT scans without contrast will show a ruptured kidney
perirenal hematoma; contrast may be contraindicated with kidney damage
or poor function. If an emergent invasive radiology procedure is
contemplated, contrast studies (urological and gastrointestinal) should
be done after angiography (13,20).

Critically ill patients with unstable pelvic injuries
require early pelvic stabilization to improve fracture stability,
provide a tamponade effect, improve clotting, and reduce pain. In
patients with multiple injuries, including life-threatening conditions,
the speed and safety of pelvic stabilization is more important than the
initial accuracy of reduction or sophistication of frame constructs.

A bed sheet wrapped and secured with towel clamps or a
hand-tied knot placed around the pelvis and greater trochanter, with
the hips slightly flexed and internally rotated, can often provide
short-term tamponade and stabilization (2 to 3 hours) (Fig. 37.5).
This stabilization method is most effective when applied after a simple
reduction maneuver using traction and pressure over the iliac wings.
Unnecessary transfers should be avoided, and the patient should only be
turned once for a spinal exam.

Commercially available pelvic binders are easy to apply and readjust as needed (Fig. 37.6).
However, these devices limit access to the abdomen and groin. Vacuum
splints and beanbag positioners, while bulky, can be helpful and allow
better abdominal and inguinal access while providing pelvic
immobilization (Fig. 37.7). It is unfortunate that they are not always available and do not work well in large patients.

Riemer at al (24) reported a
decrease in the mortality rate from 26% to 6% when external fixation
was introduced as a part of resuscitation protocol at their
institution. External fixation provides better bony stabilization than
noninvasive methods, and the technique is minimally invasive and
relatively easy and safe to apply. External fixation also helps control
pain and patient mobilization. However, an anterior frame does not
adequately stabilize translational, Tile C fracture patterns. Unlike
the posterior C-clamp, the frame may limit access to the abdomen. With
attempts to compress and immobilize the anterior pelvic ring, the
fracture gap posteriorly may be increased, which may lead to greater
instability and bleeding. Transfemoral skeletal traction of 25 to 30
lb, with the hip flexed, can improve the posterior fracture reduction.

In most trauma centers, external fixation is used
primarily as a temporary resuscitation frame until the patient’s
general condition has improved and elective internal fixation can be
employed. When anterior frames were used as a definitive fixation
method for Tile C fractures, failure rates as high as 70% were
reported. While the optimal time to convert from external to internal
fixation is unknown, we prefer to wait at least 7 days to avoid “the
second hit” phenomena. Earlier fixation may be feasible in patients in
which percutaneously placed ilio-sacral screws can produce adequate
reductions in the supine position (see Fig. 37.33).
Combined posterior–internal fixation and anterior–external fixation
(when anterior internal fixation is not applicable) can provide
adequate stability for patient mobilization. However, discomfort, pin
tract problems, and loosening limit long-term application (13,25,26,27,28,29,30).
The stability of external fixation is determined by the (a) host (type
of pelvis mechanical instability, patient size, and quality of bone);
(b) frame characteristics (design and location, number and size of
pins), and (c) application (quality of reduction and pin placement).

The bone above the acetabulum is thick and strong and
holds pins well. Biomechanical studies have been shown that pins and
frames in this “low route” provide better SI joint stability than
“upper route” (iliac crest) frames (31,32). Some authors (20)
feel that this route is ideal for emergent anterior-pelvic fixation
because of the ease of palpating this thick bone, quickly putting one
pin at each side, reducing the pelvis, and connecting the frame with a
single anterior-transverse bar. We and others (10,33)
feel that for those with limited experience with this technique, the
risk of penetrating the hip joint or damaging the neurovascular
structures in the greater sciatic notch, especially in the absence of
the c-arm, is high.

The set-up for the low route is the same as for the iliac crest procedure. We recommend c-arm control of the surgical steps.

The use of devices similar to the C-clamp were published
in the German literature in 1964 and 1972, but the modern era reemerged
with the reports of Ganz et al in 1991 and

Buckle et al in 1995 (20,35,36).
Biomechanical testing has shown that the C-clamp provides better
fixation than any other type of pelvic external fixation in posterior,
unstable, pelvic injuries (26). It improves the
conditions for effective hemostasis by compressing fracture surfaces,
eliminating motion and dislodgement of formed clots, decreasing pelvic
volume. It also may enhance self-tamponade and provides firm support
for pelvic packing when needed. Many patients show an immediate
improvement of vital signs after frame application.

The C-clamp produces direct posterior compression and stabilization, yet leaves unobstructed access to the abdomen (see Fig. 37.29) and perineum (see Fig. 37.31).
It is indicated only for a posteriorly unstable pelvic injury in a
hemodynamically unstable patient. Contraindications are hemodynamically
stable patients and those with posterior iliac-wing fractures.

The C-clamp set has a rectangular frame (Ganz) or two
semicircular tubes connected by a central ratcheting gear (Browner’s
pelvic stabilizer). Both have large pins with sharp tips, and outside
threads allow for connection with the frame and for additional dialed
compression. Sets should be sterilely packed and available in emergency
and operating rooms.

Figure 37.23 illustrates the
position of the pin insertion at the intersection of a line along the
long axis of the femur and with a vertical line angled down from the
ASIS. If landmarks are missing because of deformity and swelling, the
C-arm makes for a much safer procedure. The pin tip should be placed on
the outside surface of the ilium at the level of the reduced,
posterior, SI joint, where the bone is the thickest. The transition of
the oblique and vertical portion of the iliac wings’ lateral surfaces
is presented in Figure 37.23. With the patient
supine, the surgeon can palpate the bony landmark with a hemostat
through a 2- to 3-cm longitudinal incision on the side of injury (Figs. 37.24 and 37.25).
Compression pins are screwed into the threaded compression bolts and
attached to the arms connected with the central ratcheted gear. The
central gear is then released so the arms can be spread to accommodate
patient size, and the compression pin attached to the fixator arm is
“walked” on the lateral iliac wing until the vertical portion is felt (Fig. 37.26). The sharp tip is pushed into the bone and held there until the same procedure is done with other pin on opposite side.

When both pins are firmly anchored into the bone, the
fracture is reduced, the arms are compressed, and central gear is
tightened. Additional incremental compression is possible by screwing
the pins centrally through the compression bolts (Figs. 37.27, 37.28, 37.29, 37.30, 37.31, 37.32 and 37.33).
Overtightening should be avoided if in cases of transforaminal sacral
fracture, which can cause additional sacral-nerve damage. If the
patient’s condition does not improve despite aggressive resuscitation
efforts and pelvic stabilization, then the patient should be taken to
the operating room for laparotomy and pelvic packing (see Fig. 37.2).
Otherwise, the pins are sterilely covered, the frame supported by
towels, and pin care is assumed in day or two. Pelvic x-rays are
obtained when possible.