Pelvic / Pelvis Trauma | Emergency Department Critical Care

The stability of the pelvis can be divided into anterior and posterior stability. The anterior stability contributes 40% of the strength of the pelvis, while 60% of the pelvis' strength is derived from the posterior stabilizing structures. (9-11) It is interesting to note that the pelvis will remain stable if completely disrupted anteriorly as long as the posterior support is not disturbed.

The structures comprising the anterior support of the pelvis are the symphysis pubis and the pubic rami. The symphysis pubis is a cartilaginous joint between the two pubic bones. The articular surfaces are covered by a layer of hyaline cartilage and are connected together by a fibrocartilaginous disc. The disc has a small cavity in the midline. The joint is surrounded by the anterior and posterior symphyseal ligaments, which extend from one pubic bone to another. Almost no movement is possible at this joint.

Destot's sign is the presence of a hematoma above the inguinal ligament or over the scrotum.

Earle's sign (the presence of a bony prominence, palpable hematoma, or tender fracture line) on rectal exam. Diminished rectal tone could signify the presence of a pelvic fracture with resultant lumbosacral plexus injury. Rectal bleeding can signify a hidden open fracture of the pelvis. A high-riding or boggy prostate is significant for urologic injury with the possibility of an associated injury to the pelvis.

Most fractures of the pelvis can be seen on plain radiographs if the clinician has a knowledge of the basic bony structures of the pelvis. Familiarity with standardized radiographs will enable the physician to interpret subtle fractures that will need further evaluation and urgent orthopedic referral. (See Figure 5.) These lines are the iliopectineal (arcuate) line, the ilioischial line, the roentgenographic U or teardrop, the anterior lip/rim, and the posterior lip/rim.

The iliopectineal line is the most medial border of the pelvic rim. Disruption of this line indicates fracture of the anterior column of the acetabulum. The ilioischial line begins at the sacroiliac joint posteriorly, runs along the medial border of the ischium to the ischial tuberosity, then down to the distal juncture of the ischium with the pubic ramus. This line delineates the posterior column of the acetabulum, and disruption indicates fracture. The roentgenographic U, or teardrop, is located just medial to the femoral head. It is formed by the roof of the acetabulum and the ilioischial line. The roentgenographic U defines the quadrangular plate, the most medial aspect of the acetabulum, and disruption means penetration into the pelvic cavity. Finally, the anterior and posterior lips/rims define the lateral borders of the acetabulum. The anterior lip always is more medial, with disruption again indicating fracture. (20)

The clinical utility of the Young system stems from the fact that the different injury types (and associated complications and mortality) can be predicted from history alone. However, the mechanism of injury, and thus the Young classification, can be derived radiographically. The first clue on radiograph is the alignment of the pubic rami. Horizontal fractures suggest LC injury, while APC injury typically results in a vertical fracture. Second, the clinician should determine the direction of a hip dislocation, if present. LC injury will produce a central hip dislocation, while posterior hip dislocations are seen in APC injuries. Third, if there is crush injury to the sacrum with associated sacroiliac joint diastasis, then the injury was due to LC. Finally, VS injuries produce vertical displacement of fracture fragments. By combining these hints with a working knowledge of the fracture patterns in the Young system as presented in Table 2, the astute clinician, working with radiograph alone, can determine the Young classification for a patient with a pelvic fracture and, thus, predict the associated complication and mortality rates.

The treatment of a patient with a pelvic fracture should be in the context of a multi-system approach as prescribed by ATLS guidelines. Aggressive resuscitation is indicated in all patients suspected of incurring a fracture of the pelvis. The Young classification also suggests the typical definitive treatment required for a fracture of the pelvis. LC-I and APC-I injuries usually require a few days of bed rest followed by protected weight-bearing. LC-II fractures usually require open reduction and internal fixation (ORIF) with early mobilization; however, these fractures alternatively may be managed with 3-6 weeks of bed rest followed by progressive weight-bearing. LC-III, APC-II and III, and VS require ORIF within 5-14 days of injury. (29) It is clear, however, that early ORIF with subsequent mobilization of the patient reduces morbidity and mortality. (8) All open fractures, either due to rectal or vaginal tear, should be treated with cefazolin and gentamicin.

Fractures of the Acetabulum

Fractures of the acetabulum make up 20% of all fractures of the pelvis. Up to 13% will have an associated sciatic nerve injury. (12,13) The mechanism of injury is most commonly an MVA; however, motorcycle accidents also cause a significant number of injuries to the acetabulum. There are four types of acetabular fractures: posterior rim, transverse, iliopubic column, and ilioischial column.

Posterior rim fractures are the most commonly seen acetabular fractures. This injury pattern is seen when a posterior force is directed through the femur when the knee and hip are in a flexed position. This is seen very commonly in MVAs when the knee meets the dashboard in a head-on collision. A posterior dislocation of the hip often is seen with this injury to the acetabulum. If the patient has a dislocation, the lower extremity on the affected side will be shortened and internally rotated. On radiograph, the posterior line of the acetabulum will be disrupted. Therapy consists of analgesia, a CT scan, and orthopedic consult and admission. If a dislocation of the hip is present, it must be reduced within six hours to reduce the incidence of avascular necrosis of the femoral head. A careful neurovascular exam of the affected lower extremity must be documented before and after any attempt at reduction, as neurovascular structures can become entrapped in the joint after reduction, which would be an indication for emergent surgical intervention. After adequate analgesia and sedation, the Allis maneuver or Stimson maneuver may be used for reduction.

The Allis maneuver, the most widely performed method, involves having an assistant bilaterally stabilize the anterior superior iliac spines while the patient is supine. First, the knee is flexed, then the hip is flexed with traction placed below the knee pulling upward. The leg is internally and externally rotated until the femoral head is rearticulated with the acetabulum. The Stimson maneuver has the patient in the prone position and is the least traumatic of the closed reductions. An assistant provides pressure on the lower back for stability while the injured leg is allowed to hang from the side of the bed with the knee and hip fully flexed. Traction is applied along with the force of gravity behind the knee, while internal and external rotation is applied to pop the femoral head back into place. This technique is contraindicated in the setting of thoracoabdominal trauma or a difficult airway. (39) Post-reduction radiographs should be obtained.

Transverse fractures of the acetabulum occur when a flexed hip receives a force directed lateral to medial on the greater trochanter. This injury often is seen when the patient is involved in a "T-bone" MVA on the patient's side of the car. Central hip dislocation can be seen in these fractures. The roentgenographic U often is disrupted on plain radiograph. Treatment consists of adequate analgesia, and the patient should undergo CT scan to further define the fracture. Orthopedic consultation and admission is warranted.

Iliopubic column fractures of the acetabulum are due to a lateral to medial force directed on the greater trochanter when the hip is flexed and externally rotated. This is seen most frequently in motorcycle injuries. The iliopectineal line and anterior rim on plain radiograph are disrupted, and the roentgengraphic U is displaced medially. Central or anterior dislocation of the hip is possible in this injury. The patient should receive adequate analgesia and undergo CT scan if possible. Again orthopedic consultation and admission is necessary.

Ilioischial column fractures occur when a posteriorly directed force is applied to the knee with the thigh abducted and flexed. This is the most common acetabular fracture to have an associated sciatic nerve injury, which occurs in 25-30% of cases. (13) On plain radiograph, the ilioischial line is disrupted, and the femoral head may be displaced medially. Therapy again is directed toward adequate analgesia. The patient should have a CT scan if possible, and orthopedic consultation and admission is warranted.

Pelvis

Any displaced fx of the pelvis requires a 2^nd fracture or dislocation somewhere else in the ring

Decision point on unstable patients is blood in the peritoneal cavity. If yes, go to laparotomy. If no, go to angio suite. If the pelvic ring is open, stabilize it in the ED before angio or lap.

Acetabular Fractures

Destot’s sign is the presence of a hematoma above the inguinal ligament or over the scrotum. A Grey-Turner sign (flank ecchymosis secondary to retroperitoneal hemorrhage) also may be found.

Earle’s sign (the presence of a bony prominence, palpable hematoma, or tender fracture line) on rectal exam.

The Allis maneuver, the most widely performed method, involves having an assistant bilaterally stabilize the anterior superior iliac spines while the patient is supine. First, the knee is flexed, then the hip is flexed with traction placed below the knee pulling upward. The leg is internally and externally rotated until the femoral head is rearticulated with the acetabulum. The Stimson maneuver has the patient in the prone position and is the least traumatic of the closed reductions. An assistant provides pressure on the lower back for stability while the injured leg is allowed to hang from the side of the bed with the knee and hip fully flexed. Traction is applied along with the force of gravity behind the knee, while internal and external rotation is applied to pop the femoral head back into place. This technique is contraindicated in the setting of thoracoabdominal trauma or a difficult airway.³⁹ Post-reduction radiographs should be obtained.

Transverse fractures of the acetabulum occur when a flexed hip receives a force directed lateral to medial on the greater trochanter. This injury often is seen when the patient is involved in a “T-bone” MVA on the patient’s side of the car. Central hip dislocation can be seen in these fractures. The roentgenographic U often is disrupted on plain radiograph. Treatment consists of adequate analgesia, and the patient should undergo CT scan to further define the fracture. Orthopedic consultation and admission is warranted.

Binders

Injury
Volume 38, Issue 1 , January 2007, Pages 125-128
Immediate application of improvised pelvic binder as first step in extended resuscitation from life-threatening hypovolaemic shock in conscious patients with unstable pelvic injuries
Technique
When the need to apply a pelvic binder is recognized, a cotton draw sheet (not a bed sheet) is folded lengthwise to make a strip approximately 15 cm across. A pillow is rolled up into a bolster and secured with sticky tape. Two assistants gently lift the patient's legs and place the bolster behind the patient's knees. A 15-cm crepe bandage is applied to bind the lower thighs together and a second bandage is applied (with padding) at the ankles. This internally rotates both lower limbs, which act as levers on the displaced pelvis. The draw sheet is eased beneath the patient at the level of the greater trochanters and is gently secured anteriorly by crossing the ends and loosely applying two cable ties. The assistants then stand on either side of the patient, level with the greater trochanters, and lean towards one another with one hand on the nearest greater trochanter. A push-pull is performed, with the assistant's free hand pulling on the nearest end of the draw sheet. Thus the pelvis is sequentially reduced and the binder tightened. The doctor leading the procedure then secures the draw sheet using cable ties (Fig. 1). The improvised pelvic binder requires equipment that can be commonly found in any resuscitation room, and has been successfully applied to patients in extremis with hypovolaemic shock, but still conscious at the time of binder application.

Angio

Even unstable patients should be transported to the suite. (AJR Am J Roentgenol 1991;157(5):1005-1014.)

Overall 7-11% of pelvic fractures will require embolization. Only 2% of lateral compression fractures have demonstrable arterial haemorrhage, compared to 20% of anteroposterior compression, vertical shear or combined mechanism injuries. (Pelvic Ring Disruptions: Effective Classification System and Treatment Protocols. J Trauma 30(7);848-856:1990)

'We conclude that patients with anterior-posterior compression type 2 and 3, lateral compression type 2 and 3, or vertical shear injuries, who are hemodynamically unstable as a result of their pelvic fracture, should undergo immediate ANGIO if laparotomy is not indicated.' Non-randomised, small study. However no patient undergoing emergent angiography required a second intervention to control bleeding, compared to 50% of the external fixation group, who went on to angiography. Also massive thigh/buttock/flank haematomas seen in the ex-fix group. (A protocol for the initial management of unstable pelvic fractures. Am Surg 1998 64(9): 862-7)

'embolization in conjunction with binding the thighs or skeletal traction may facilitate the resuscitation process and preclude emergent frame application.' (Hemodynamicaly Unstable Pelvic Fractures: Retrospective Review of Early Embolization. OTA Annual Meeting 2000)

'Posterior arterial bleeding (internal iliac or its posterior branches) was statistically more common in patients with unstable posterior pelvic fractures, and anterior arterial bleeding (pudendal or obturator) was more common in patients with lateral compression injuries.'
Abstract: Pelvic fractures are high energy injuries indicative of significant trauma. Hypotension and significant blood loss is common in skeletally unstable pelvic fractures. Potential sites of intrapelvic bleeding include fractured bone edges, venous injuries and/or arterial vascular injuries. In an attempt to define the relationship of fracture pattern to arterial injury, a specific subset of 39 patients with pelvic fractures who underwent angiography for hemodynamic instability or ongoing blood loss were reviewed retrospectively. In 35 patients with definable arterial injuries, 20 (57%) had multiple bleeding sites. Posterior arterial bleeding (internal iliac or its posterior branches) was statistically more common in patients with unstable posterior pelvic fractures, and anterior arterial bleeding (pudendal or obturator) was more common in patients with lateral compression injuries. The pudendal artery was the most commonly injured vessel in this series. The superior gluteal artery was the most commonly injured vessel associated with posterior pelvic fractures. There was no correlation between fracture pattern and survival. The injury severity score however, did indirectly correlate to survival. In addition, the presence of hypotension (systolic blood pressure < or = 90) at the time of arrival to the trauma center was found to significantly increase mortality. (Angiographic findings in pelvic fractures. Clin Orthop 1996 Aug(329):60-7)

Report on one centers use of early embo and vasopressors (J Trauma 2005;58:978)

STC Protocol

Stable

Unstable

Best Review (Crit Care 2007;11:204)

Unstable pelvic fracture with ongoing bleeding
stabilize the fracture
externally with a sheet (works fine).

Rule out abdominal bleeding by DPL or
FAST. If abdomen negative and if successfully resuscitated, but signs of
ongoing bleeding the patient is taken to angiography (available 24/7/365 on
30 minutes notice) However, time to successfully embolized will always be
longer... worst case the patient has to be kept reasonably stable for 1,5 to
2 hours before the procedure is completed.

If refractory to ongoing resuscitation and no abdominal bleeding, the pelvis
is packed extraperitoneally (we have full OR equipment in the ED). Incision
midline from symphysis to umbilicus, through skin and fascia. Palpate the
symphysis anteriorly. Follow the pelvic brim (linea terminalis)
laterally/posteriorly to the ileosacral joints. Following this plane
distally open the pelvic cavity (blunt finger dissection)on both sides of
the bladder down to the pelvic floor (it is the plane dissected by the
hematoma). Tightly pack both sides starting from the pelvic floor(tight
means 3 large abdominal swabs on each side distal to the linea terminalis in
a normal adult pelvis)The packing is held in place by the peritoneum
cranially, and does not cause ACS. The technique is supplemented by
angiography when needed.

Detailed description of extra-peritoneal packing approach (J Trauma 2005;59:1510)

journal of trauma Volume 62(4), April 2007, pp 843-852
Volume 62(4), April 2007, pp 834-842
another extra-p packing

The patient is positioned supine. In cases in which mechanical stabilization is judged to be advantageous, a C-clamp or external fixator is placed using standardized techniques.10 An 8-cm midline incision is made extending caudally from the symphysis pubis in a cephalad direction (Fig. 3). Skin and subcutaneous tissue are sharply incised and the fascia anterior to the rectus abdominis is exposed. The fascia is divided in the midline, over the length of the incision. Care is taken to protect the bladder during incision because in some cases of symphyseal disruption, the bladder may be pressed against the posterior aspect of the abdominal wall. The bladder is gently retracted to one side with a malleable retractor (Fig. 4) and the pelvic brim is gently palpated from the symphysis in a posterior direction toward the sacroiliac joint. In most cases, the fascial connections of the overlying tissue will have been dissected free by the force of the injury. Care should be taken to palpate for any aberrant vascular connections between the obturator and iliac systems to avoid avulsing these vessels (the Corona Mortis).11 The pelvic brim is not visualized through the approach. After the brim has been palpated as posterior as the surgeon can reach, three laparotomy sponges are placed sequentially deep to the brim. The first is placed on a sponge stick posterior just below the sacroiliac joint. The second is placed anterior to the first sponge at a point corresponding to the middle of the pelvic brim. The third sponge is placed in the retropubic space just deep and lateral to the bladder. The bladder is then retracted to the opposite side and the sequence is repeated until both sides of the pelvis are symmetrically packed with three sponges each. The packs should all be below the pelvic brim in the true pelvis (Fig. 5). At this point, any bleeding evident upon opening of the retroperitoneum will have stopped. If bright red bleeding indicative of arterial bleeding was noted initially, consideration should be given to subsequent pelvic angiography either via a laparotomy by the trauma surgeon or percutaneously by the interventional radiologist upon leaving the operative room. The outer fascia is closed with a single layer running suture to seal the compartment and the skin incision is stapled. The total time for the packing procedure should be under 20 minutes. If laparotomy is required, it should follow the closure of the retroperitoneal fascia to preserve the anatomic integrity of the compartments and to allow for tamponade in the retroperitoneum. Laparotomy before pelvic packing may result in a difficult approach into the retroperitoneum and prolong the overall procedure time. As in the abdomen, the pelvic packing should be removed or exchanged at 24 to 48 hours. Packing should be removed carefully with saline added to moisten the packs and lessen blood clot disruption. In most cases, the temporizing fixation can be converted to definitive fixation at the time of packing removal.

Review of outcomes retrospective (Injury Volume 40, Issue 1, January 2009, Pages 54-60 )

In summary, we describe a simple clinical prediction rule that can be used to predict the risk of pelvic arterial bleeding based on pulse of 130 or greater, hematocrit of 30 or less, diastasis of the pubic symphysis of 1 cm or more, and obturator ring fracture displaced 1 cm or more. A combination of these four factors can be used to identify subjects at high (>60%) and very low (<2%) probability of major arterial pelvic hemorrhage. (J Trauma 2006;61(2):346)

Brown CVR, Kasotakis G, Wilcox A, et al. Does pelvic hematoma on

admission computed tomography predict active bleeding at angiography

for pelvic fracture? Am Surg 2005;71:759-762.

This is an important article for all of us who deal with pelvic fractures.

The authors reviewed the records of all 37 of their patients, seen over a

3-year period, who had a pelvis CT and then went to angiography. They

found that neither the size of the pelvic hematoma seen on CT nor the

absence of an arterial blush on CT had any correlation with whether there

was active bleeding found at angiography. Yes, large hematomas and

contrast blush did most often—but not always—portend active bleeding,

but even patients with no hematoma and no contrast blush often had active,

embolizable, bleeding. So, what then are good indications for angiography?

They are hemodynamic instability (this is one of the few instances in which

angiography is the place to go with a hemodynamically unstable patient);

need for transfusion; significant fracture pattern, such as sacroiliac

disruption, diastasis of the symphysis pubis greater than 2.5 cm, and

bilateral superior and inferior pubic rami fractures; and finally, a large

pelvic hematoma and/or contrast blush seen on pelvic CT.

Ziran BH, Chamberlin E, Shuler FD, et al. Delays and difficulties in the

diagnosis of lower urologic injuries in the context of pelvic fractures.

J Trauma 2005;58:533-537.

The association of lower urinary tract (bladder and urethra) injury with

fracture of the bony pelvis ranges from 7% to 25%. Conversely, 80% of

bladder ruptures are associated with pelvic fracture. Bladder ruptures may

be intraperitoneal or extraperitoneal. Complications of missed bladder

rupture include entrapment of the muscular bladder wall within the pelvic

fracture, persistent urinary leakage, pelvic abscess, peritonitis, respiratory

difficulties, and sepsis from contaminated urine. Urethral injuries occur, by

far, primarily in males, and most often are located at bulbomembranous

junction. Complications of unrecognized urethral injuries include incontinence,

impotence, and stricture formation. This study was initiated to

identify missed lower urinary tract injury in patients with pelvic fractures

and the clinical implications of such injuries. The records of 635 patients

with pelvic fractures were reviewed. Forty-three of these had lower urinary

tract injuries. All patients with urologic injury had some type of significant

anterior pelvic ring injury. The mechanism of injury included MVCs,

industrial accidents, falls, and pedestrian injury. Fifteen intraperitoneal and

14 extraperitoneal bladder ruptures were identified. Thirteen patients had

complete urethral tears, and 1 patient had both a urethral tear and

extraperitoneal bladder rupture. In 10 patients, urologic injury was missed

on initial evaluation, including 4 intraperitoneal and 3 extraperitoneal

bladder ruptures and 3 urethral tears. All 4 of the patients with a missed

intraperitoneal bladder rupture had gross blood in the Foley catheter;

cystography was falsely negative in 1 patient, 1 cystogram was read

incorrectly as an extraperitoneal rupture, and the remaining 2 cystograms

were read as inconclusive. Extraperitoneal ruptures were not diagnosed

initially in 3 patients; all of these patients had gross blood with Foley

catheter insertion also. In these 3 patients, cystogram was misread as an

intraperitoneal rupture in 1, inconclusive in 1, and falsely negative in 1; the

last patient developed urinary retention 17 days after injury and cystoscopy

revealed an extraperitoneal rupture. Urethral injuries were missed in 3

patients, all of whom had 4 pubic rami fractures in addition to a sacral ala

fracture. Urethral tears in 2 patients were diagnosed at the time of urgent

exploratory laparotomy; neither of these 2 patients had blood at the urethral

meatus or abnormal prostate, but there was gross hematuria upon Foley

catheter placement. One patient with a urethral tear had a straddle fracture

associated with a sacral ala fracture; this patient similarly had no blood at

the meatus or abnormal prostate, but there was gross blood at the placement

of the Foley. The authors concluded that in patients with multiple injuries,

signs of urologic injury may not be obvious. Gross blood with Foley

catheter placement is present in 95% of the patients with bladder rupture.

Uroradiographic studies are indicated in any patient with gross hematuria

and must be carefully performed and carefully read. The authors emphasize

the importance of performing a cystogram which fully distends the bladder

and then performing a postevacuation pelvic film to demonstrate any

obscured extravasation. As to urethral injuries, approximately half of the

patients will not manifest any of the classic signs of blood at the meatus,

scrotal or perineal hematoma, or high-riding or boggy prostate. The authors

emphasize the importance of evaluating the pattern of pelvic fracture, which

might suggest urethral disruption: patients with Malgaigne's fractures have

a 3 1/2–fold increase in urethral injuries, and patients with straddle injury

associated with ipsilateral sacroiliac involvement have a 24-fold increase.

Shapiro M, McDonald AA, Knight B, et al. The role of repeat angiography

in the management of pelvic fractures. J Trauma 2005;58:227-232.

Hemorrhage from a pelvic fracture can be a difficult, potentially lethal,

problem. Most often, approximately 80% of the time, bleeding from pelvic

fractures is from small veins and venous plexus(es), and only 1 in 5 patients

will actually have an arterial source. In the 1970s, before the advent of

interventional radiology and angiographic embolization, trauma surgeons

tried operative ligation of both internal iliac arteries in an attempt to stop

ongoing hemorrhage from pelvic fractures, with quite poor results. The

reasons for failure were many but include both the fact that most of the

538 The Literature of Emergency Medicine

bleeding is indeed venous, as well as the rich collateral blood flow to the

pelvic bones and ligaments from arteries other than the internal iliacs.

Angiographic embolization, on the other hand, coupled with restoration of

the pelvic bones to normal apposition with some method of external

compression and fixation, has been very effective in staunching pelvic

bleeding. This article asks the question, what do you do if a patient with a

bad pelvic fracture continues to bleed even after angiography? The authors'

retrospective review found 678 patients with pelvic fracture in a 2 1/2–year

period, 31 of whom went to angiography for bleeding. Arterial hemorrhage

was diagnosed and embolized initially in 16 patients; 3 of these required

repeat angiography and embolization due to ongoing pelvic hemorrhage.

Fifteen patients initially had negative arteriography; 5 of these were

returned to angiography for ongoing bleeding, and 4 of the 5 had had

arterial bleeders that were successfully embolized. The authors quite rightly

emphasize that other sources of ongoing bleeding must be ruled out. But if

they are, and if after angiography the patient continues to bleed, as manifest

by continued or recurrent hypotension and persistent base deficit greater

than 10 for more than 6 hours, return to the angiography suite is the right

thing to do.

This patient sustained a Morel-Lavalle lesion. The Morel-Lavalle lesion is a closed internal degloving injury that is recognized clinically as significant soft-tissue ecchymosis, typically in the region of the greater trochanter. It is seen in association with pelvic trauma and is frequently associated with acetabular fractures. A cavity of hematoma and liquefied fat is produced from a shear injury in which the subcutaneous tissue is torn away from the underlying fascia. These injuries have been reported to result in serious infection in over 45% of patients (1).

The clinical significance of this injury may not be initially apparent: its clinical appearance may not convey the serious soft tissue injury that is indicated by the lesion and it may be overlooked as attention is focused on bony injuries.

As noted, there is a high incidence of bacterial colonization in closed degloving injuries associated with severe pelvic trauma. The Morel-Lavalle lesion should be treated by thorough debridement prior to or at the time of the pelvic or acetabular surgery.

Burgess A, Eastridge BJ, Young JWR, Ellison TS, Ellison PS, Poka A, Bathon GH, Brumback RJ (1990). 'Pelvic Ring Disruptions: Effective Classification System and Treatment Protocols.' J Trauma 30(7): 848-856.

There is little utility in detailed classification or further delineation of fracture pattern at this stage with regard to the immediate management of the pelvic injury. However certain injury combinations are associated with different pelvic fracture patterns:

Dalal SA, Burgess AR, Siegel JH, Young JW, et al. (1989). 'Pelvic fracture in multiple trauma: classification by mechanism is key to pattern of organ injury, resuscitative requirements, and outcome.' J Trauma 29(7): 981-1000;

%	Thorax	Liver	Spleen	PV	RPH	Shock	Mort
TYPE
LC1	27	6	13	0	5	31	14
LC2	36	5	9	9	14	32	14
LC3	0	0	0	20	60	40	0
APC1	24	6	9	6	27	30	15
APC2	39	11	17	17	36	33	22
APC3	19	7	19	22	52	67	37
VS	24	6	24	12	47	65	24
CMI	25	5	18	8	20	45	18

LC: Lateral Compression, APC: Anteroposterior Compression,
VS: Vertical Shear, CM: Combined Mechanism
PV: Peripheral Vascular; RPH: Retroperitoneal Hematoma.

The magnitude of base deficit on admission best reflects volume status and predicts the survival. The LD 50 is at a base deficit of -11.8 mmol/l. on admission. Brain injury, ARDS, shock are simultaneously significant in predicting death with LC injuries. Only ARDS and circulatory shock are simultaneously significant in predicting death with APC injuries.

Ochsner MG Jr; Hoffman AP; DiPasquale D et al. 'Associated aortic rupture-pelvic fracture: an alert for orthopedic and general surgeons.' J Trauma 1992 Sep;33(3):429-34

Abstract: Blunt trauma patients with pelvic fractures have been shown to have a two-fold to five-fold increased risk of aortic rupture compared with the overall blunt trauma population. A retrospective review was performed to determine whether the relationship between aortic rupture and pelvic fracture could be further delineated using a pelvic fracture classification based on mechanism of injury. Of 4,157 consecutive blunt trauma patients, 371 (8.9%) had pelvic fractures, 34 (0.8%) had ruptured thoracic aortas and 12 had both injuries. When pelvic fractures were classified according to vector of force, 10 of 12 (83%) aortic ruptures occurred in patients with an anterior-posterior compression fracture pattern, an incidence of aortic rupture eight times greater than that of the overall blunt trauma population. There was no increased incidence of aortic rupture among patients with any other pelvic fracture pattern. We conclude that the previously reported association between aortic rupture and pelvic fracture can be further specified to include, predominantly, those patients with an anterior-posterior compression fracture pattern.

Mechanism and Type	Characteristics	Hemipelvis Displacement	Stability
AP compression, type I	Pubic diastasis <2.5 cm	External rotation	Stable
AP compression, type II	Pubic diastasis >2.5 cm, anterior SI joint disruption	External rotation	Rotationally unstable, vertically stable
AP compression, type III	Type II plus posterior SI joint disruption	External rotation	Rotationally unstable, vertically unstable
Lateral compression, type I	Ipsilateral sacral buckle fractures, ipsilateral horizontal pubic rami fractures (or disruption of symphysis with overlapping pubic bones)	Internal rotation	Stable
Lateral compression, type II	Type I plus ipsilateral iliac wing fracture or posterior SI joint disruption	Internal rotation	Rotationally unstable, vertically stable
Vertical shear	Vertical pubic rami fractures, SI joint disruption +/- adjacent fractures	Vertical (cranial)	Rotationally unstable, vertically unstable

Pelvic Trauma