Unstable Pelvic Fractures Treatment & Management

Updated: Oct 01, 2020
  • Author: Kenneth W Graf, Jr, MD; Chief Editor: William L Jaffe, MD  more...
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Approach Considerations

The treatment goals for unstable pelvic fractures are the same as those for fractures of other bones—namely, a healed fracture with the prevention of nonunion, malunion, and other defined complications. The initial priority in a hemodynamically unstable patient is aggressive resuscitation and prevention of further hemorrhage. External fixation is indicated as the immediate treatment in a hemodynamically unstable patient with an unstable pelvic fracture.

Open reduction with internal fixation (ORIF) is preferred for definitive management and has been demonstrated to provide superior results. Operative indications include the following:

  • Diastases of pubic symphysis greater than 2.5 cm
  • Sacroiliac (SI) joint dislocations
  • Displaced sacral fractures
  • Crescent fractures
  • Posterior or vertical displacement of the hemipelvis greater than 1 cm
  • Rotationally unstable pelvic ring injuries
  • Sacral fractures in patients with unstable pelvic ring injuries that require mobilization
  • Displaced sacral fractures with neurologic injury

ORIF is contraindicated in patients who are unstable and critically ill or who have severe open fractures with inadequate wound debridement, crushing injuries, and placement of a suprapubic tube in the operative field. Additionally, a Morel-Lavalle lesion can be considered a contraindication to ORIF. This lesion is identified on the basis of a fluctuance under the skin of the involved area.

Contusions and abrasions are often associated with the Morel-Lavalle lesion. It represents a large area of hematoma and fat necrosis under degloved skin. The lesion results from shearing of the subcutaneous tissue from the underlying fascia. Although the Morel-Lavalle lesion is a closed injury, it is associated with high rates of bacterial contamination and thus must be treated with debridement and drainage before operative intervention is considered.

Specific contraindications for percutaneous fixation include a dysmorphic upper sacrum, obesity, skin compromise, and poor fluoroscopic images.

The World Society of Emergency Surgery (WSES) has published guidelines for the management of pelvic trauma. [35] [See Guidelines.]


Medical Therapy

The initial evaluation and treatment of a patient with multiple trauma occur in the emergency department (ED). The Advanced Trauma Life Support (ATLS) recommendations for airway stabilization followed by breathing and circulation (ie, the ABCs) are followed. A multidisciplinary approach is employed that should include the following, as needed: emergency medicine, general surgery, neurosurgery, and orthopedic surgery. [36]

Patients with high-energy pelvic fractures often have abdominal, head, and thoracic injuries. Between 60% and 80% of patients have musculoskeletal injuries, 12% have urogenital injuries, and 8% have lumbosacral injuries.

Aggressive fluid resuscitation is critical in the patient who is hemodynamically unstable. The severity of blood loss can be determined by assessing the pulse, blood pressure, and capillary refill. These indicators can be used to evaluate a patient's response to the resuscitative effort. Two large-bore (16-gauge) intravenous catheters should be placed.

Replacement volume is estimated by using the formula of 3 mm of crystalloid for each 1 mm of blood loss. A minimum of 2 L of crystalloid solution is given over 2 minutes, or more rapidly if the patient is in shock. If an adequate blood pressure measurement is obtained, crystalloid is administered until type-specific blood or non-cross-matched universal donor (O-negative) is prepared.

Displaced pelvic fractures can be stabilized temporarily by simple means during the initial evaluation and transportation. These methods rely on immobilization and partial reduction of displacement. A sheet can be tied around the pelvis, or the legs can be tied together in an internally rotated position to approximate an anterior pelvic diastasis.

Military antishock trousers (MAST) have proved to be effective in the prehospital treatment of patients who are hypotensive and have pelvic fractures. Their use in the hospital is not common, because they limit access to injured areas of the body, decrease expansion of the lungs, and may contribute to the development of compartment syndrome in patients who are hypoperfused.

Most incidents of blood loss from a pelvic injury arise from cancellous bone at the fracture site or from a retroperitoneal lumbar plexus venous injury. [37] Only 20% of deaths from pelvic hemorrhage are attributed to a major arterial injury. Posterior arterial bleeding is more common in patients with unstable posterior pelvic fractures, and anterior arterial bleeding (pudendal or obturator) is more common in patients with lateral compression (LC) injuries. [38] The arterial vessel most frequently injured with a posterior fracture is the superior gluteal artery.

The Eastern Association for the Surgery of Trauma (EAST) has published guidelines for managing hemorrhage in pelvic fracture. [39]  Guidelines on management of hemodynamically unstable pelvic trauma have also been developed by the First Italian Consensus Conference on Pelvic Trauma. [40] (See Guidelines.)

Hemorrhage from a pelvic fracture is seldom the only source of bleeding. Poole described a large series of multiply injured patients with pelvic fractures in whom nonpelvic sites were the major source of bleeding. [41] The abdomen and bladder are frequently injured and should be evaluated as sources of hemorrhage. As mentioned, supraumbilical diagnostic peritoneal lavage (DPL) can be used as a quick and accurate diagnostic tool.

If DPL results are negative and the patient remains hemodynamically unstable, external fixation (see Surgical Therapy) may have a role in the patient's immediate treatment. [42] Riemer documented an overall decrease in mortality, from 26% to 6%, after initiating a protocol that included external fixation and early mobilization for pelvic fractures. [17] The mortality for hypotensive patients decreased from 41% to 21%.

Continued unexplained blood loss despite fracture stabilization and aggressive resuscitation mandates angiographic exploration to look for continued arterial bleeding. [43, 44] The techniques for arteriography and embolization were developed in the 1970s. Embolization provides the most direct and beneficial means of controlling arterial hemorrhage. It avoids the retroperitoneal contamination associated with operative ligation of bleeding vessels while preserving the tamponade effect in the retroperitoneal space.

The timing of arteriography and embolization is controversial. Most authors recommend arteriography after the initial stabilization, laparotomy, or both. A skilled radiologist is critically important. Aggressive fluid resuscitation must be continued during angiography. Hypothermia may develop during a prolonged radiographic procedure if the patient is not adequately warmed and resuscitated.

Extraperitoneal pelvic packing (EPP) appears to be a safe and quick means of enhancing hemodynamic stabilization and reducing acute hemorrhage-related mortality in hemodynamically unstable pelvic fracture patients, in combination with optimal transfusion. [45] It may be useful as a bridge to angioembolization or other time-consuming procedures. The packing should be removed early to reduce the risk of infectious complications. [46]

In a network meta-analysis of 13 clinical trials (N = 24,396), Tang et al attempted to identify an optimal sequence of surgical procedures for hemodynamically unstable patients with pelvic fracture. [47] They concluded that the initial application of an external fixator was strongly supported and that for patients who remained hemodynamically unstable after application of an external fixator, EPP should be the next procedure to consider. They found angioembolization to be the complementary, but not alternative, subsequent method of choice.


Surgical Therapy

The goals of treatment are the same for pelvic fractures as for fractures of other bones—a healed fracture with the prevention of nonunion, malunion, or other complications.

External fixation also has been used in rotationally unstable pelvic fractures. [48, 49, 50] Benefits of external fixation include immobilization of fractures limiting the clot disruption that may occur during patient movement and transfer. Studies have shown that reduction of an open-book pelvis leads to an increase in retroperitoneal pressure, which may aid in the tamponade of venous bleeding.

The use of external fixation has been controversial. For example, Gruen et al reported that in 36 trauma patients who were hemodynamically unstable, pelvic fractures were not immediately stabilized by external fixation. [51] These patients received both volume resuscitation and treatment of associated injuries. About 39% of the fractures were rotationally unstable, and 61% were both rotationally and vertically unstable. Overall mortality was 11%. All of the deaths were attributed to associated injuries or comorbidities.

However, Baron et al, in a study of unstable APC pelvic ring injuries treated with surgery and followed for a minimum of 3 years, compared internal fixation with external fixation of the anterior pelvic ring (supplemented with posterior iliosacral screw fixation, depending on the injury) and suggested that long-term results with the two approaches may not differ significantly in these patients. [52]

In most cases, ORIF is preferred for definitive management and has been demonstrated to give superior results. Operative indications include the following:

  • Diastasis of the pubic symphysis greater than 2.5 cm
  • SI joint dislocations
  • Displaced sacral fractures
  • Crescent fractures
  • Posterior or vertical displacement of the hemipelvis greater than 1 cm
  • Rotationally unstable pelvic ring injuries
  • Sacral fractures in patients with unstable pelvic ring injuries that require mobilization
  • Displaced sacral fractures with neurologic injury

Minimally invasive approaches to fixation have been described that may yield results comparable to those of conventional fixation in patients with unstable pelvic fractures. [53, 54, 55, 56, 57]

Preparation for surgery

The mechanism of injury, soft-tissue condition, and patient positioning should be reviewed. Repeating a rectal and gynecologic examination before beginning the open procedure is also important to ensure that the fracture is not open.

Plain radiographs, including anteroposterior (AP) pelvis, inlet views, and outlet views, should be obtained and reviewed. Computed tomography (CT) is helpful in evaluating the sacrum and the SI joint for injury. [32]  It is also worthwhile to review a catalogue of injuries before proceeding to the operating room.

If percutaneous fixation is deemed acceptable for treatment, good fluoroscopic images should be obtained before the patient is prepared and draped. The need for skeletal traction must also be determined before definitive fixation. If a femoral traction pin is to be used, it should be placed before internal fixation.

Definitive internal fixation typically is not performed immediately after the injury. Instead, it is usually performed 2-3 days after stabilization of the patient. However, if a laparotomy is performed and an unstable anterior lesion is present, internal fixation of the symphysis may be performed.

Operative details

External fixation

External fixation is indicated for patients with pelvic fractures who are hemodynamically unstable. It should be avoided in patients who are hemodynamically stable except in those select cases where it will serve as definitive stabilization. [58] Infected or contaminated pin sites may compromise future approaches to the anterior SI joint and the iliac wing.

The surgeon must be familiar with the external fixation equipment so that it can be used quickly and effectively in patients who are hemodynamically unstable. Pins may be placed either along the iliac crest or in the supra-acetabular region.

Placement in the iliac crest is simple and direct; this location is most appropriate for rapid pin placement in a patient who is hemodynamically unstable (see the image below). The thickest bone for pin insertion is the anterior pillar of the iliac wing. Anatomically, the iliac crest overhangs laterally. A pin placed in the center of the crest will miss the iliac wing. The optimal starting point is in the medial one third of the anterior pillar.

External fixation of anterior-posterior compressio External fixation of anterior-posterior compression (APC) pelvic fracture.

Supra-acetabular pins are placed at the level of the anterior inferior iliac spine in a direction perpendicular to the floor. This pin is near the hip joint and must be inserted with great care. The skin incisions should be placed in line with the direction of the planned reduction. This avoids the need for additional relaxing incisions.

A spinal needle or Kirschner wire (K-wire) can be placed along the inner table of the pelvis to help determine the orientation of the hemipelvis. Frame constructs are varied. The frame should be far enough away from the abdomen to allow for distention, future surgical approaches, and upright positioning.

Iliosacral screws

Iliosacral screws can be used in the treatment of crescent fractures, sacral fractures, and SI dislocations. They can be placed through either open or percutaneous techniques. [8, 59]  If percutaneous techniques are chosen, an anatomic reduction is required because sacral displacement narrows the safe window for screw placement.

The procedure can be performed with the patient in either the supine or the prone position. The technique is technically demanding and requires good C-arm visualization. A thorough understanding of the radiographic anatomy is critical in performing this procedure. The pelvic inlet, outlet, and lateral sacral views must be obtained to define the safe corridor for screw placement. Three-dimensional (3D) CT of the pelvis has also been used to guide iliosacral screw placement. [60]

The ideal pelvic inlet view superimposes the upper sacral vertebral bodies as concentric circles. If the anterior cortex of S1 overlies the coccyx, the concavity of the sacrum may not be appreciated. This may result in a screw penetrating the S1 body. The ideal pelvic outlet view is obtained when the symphysis is superimposed on the second sacral vertebral body; this view allows visualization of the S2 foramina. A lateral sacral view is obtained by superimposing the greater sciatic notch images.

The iliac cortical density denotes the anterior extent for safe placement of the iliosacral screw insertion. The angle of screw placement may vary between SI dislocation and a sacral fracture. The screw placement for a sacral fracture must be in a transverse position to allow the screw to achieve fixation in the sacral body.

Sacral fractures are treated with fully threaded cancellous screws to avoid overcompression of the sacral foramina. SI dislocations are compressed with cancellous lag screws. If an open approach is necessary for reduction of the SI dislocation, either an anterior or a posterior approach may be taken.

For the posterior approach, a vertical incision is made 2 cm lateral to the posterior superior iliac spine (PSIS). The gluteal muscle is elevated from the posterior iliac crest, and the gluteus maximus origin is reflected from the sacrum. The greater sciatic notch must be exposed for assessment of reduction.

For sacral fractures, the multifidus is elevated to provide visualization of the sacral foramina. A Matta angled jaw clamp can be used to obtain reduction by placing one tip on the sacrum through the sciatic notch and the other along the outer table of the ilium. Fixation is performed with iliosacral screws.

For an anterior approach, the incision is from the anterior superior iliac spine (ASIS) to the iliac tubercle. The iliacus is sharply dissected subperiosteally off the iliac wing. The L5 nerve root lies 2 cm medial to the SIJ and must be protected during dissection. Fixation is usually limited to a pair of two-hole plates placed at 90° to each other. In a study of 27 patients with SI dislocations treated via an anterior approach, three (11%) had incomplete L5 nerve injuries postoperatively, with full improvement occurring in two of them. [61]

Crescent fractures can be approached via an anterior or posterior approach. [13]  The posterior approach provides an easier dissection, without requiring special care for the L5 nerve root. The iliac wing fragment can be reduced to the intact PSIS and fixed in place with one or two cortical lag screws (3.5 mm) placed between the pelvic tables from posterior to anterior. A 3.5-mm reconstruction plate can be placed along the outer table to help neutralize the rotational and shear forces across the fracture site.

If the intact PSIS fragment is small, iliosacral screws may be required to stabilize the iliac wing.


Postoperative Care

Postoperative weightbearing status depends on the fracture pattern and associated injuries. Most unstable fractures require nonweightbearing restrictions for 3 months. Early weightbearing may be allowed in individuals with rotationally unstable but vertically stable fractures. All patients should be out of bed or upright in bed on postoperative day 1 to help pulmonary function. [62]



Complication rates for unstable pelvic injuries are high. An awareness of the complications and adequate preoperative planning can reduce these rates.

The Morel-Lavalle lesion is a significant soft-tissue injury associated with pelvic trauma. The subcutaneous tissue is torn away from the underlying fascia, creating a cavity filled with hematoma and liquefied fat. The diagnosis is based on physical examination findings, including a soft fluctuant area that commonly occurs over the greater trochanter but may also occur in the flank and lumbodorsal region. Management is important because the presence of necrotic tissue and hematoma in the subcutaneous tissue increases the risk of infection.

Open debridement is the preferred treatment. The incision should be placed close to the middle of the degloved area to decrease the risk of flap necrosis. The hematoma should be evacuated, and the necrotic fatty and connective tissue should be sharply debrided. The wounds should be packed with gauze, and dressings soaked with isotonic sodium chloride solution should be changed regularly. Prophylactic antibiotics should particularly cover gram-positive organisms.

If the overlying skin is intact, debridement can be performed at the time of fracture fixation. The deep fascia should be closed tightly, and the distal portion of the wound should be left open for dressing changes.

The incidence of deep venous thrombosis (DVT) in patients with pelvic trauma has been reported to be 35-60%. Geerts et al performed venography on 100 patients with pelvic fractures and found a 61% incidence of DVT and a 29% incidence of proximal DVT. [63] The incidence of symptomatic pulmonary embolism (PE) in pelvic trauma is 2-10%. Fatal PE occurs in 0.5-2% of patients with pelvic trauma.

The risk factors most consistently observed with a trauma population are increasing age, spinal cord injury, fractures of the lower extremity and pelvis, and duration of immobilization. The typical clinical findings of DVT include leg tenderness, swelling, and increased temperature. The sensitivity of detecting DVT in a patient with trauma is unreliable because lower-extremity fracture, edema, and soft tissue injury are often present. Duplex ultrasonography (US) is the most widely used screening test for the evaluation of DVT in trauma patients.

Given the high incidence of DVT in the pelvic trauma population, routine prophylaxis is recommended. Common forms of prophylaxis include low-dose heparin (LDH), low-molecular-weight heparin (LMWH), mechanical devices, and vena caval filters. Knudson et al performed a randomized trial of LDH with no prophylaxis in 154 trauma patients. [64, 65] Serial duplex Doppler US was performed every 3-5 days. Patients treated with LDH received no additional protection, as compared with controls.

Intermittent pneumatic compression has been demonstrated by itself to be ineffective prophylaxis for trauma patients. Fisher et al performed a randomized study of intermittent pneumatic compression in patients with pelvic fractures. [66] They found no significant difference in DVT rates. LMWH is more efficacious than LDH in preventing DVT (19% vs 12%). The use of LMWH has been associated with an increased risk of wound hematoma formation. The authors prefer warfarin prophylaxis for postoperative patients.

Treatment of DVT in persons with pelvic trauma depends on whether the patient requires surgical reconstruction. DVT can be identified both preoperatively and postoperatively. In patients who will be treated nonoperatively or with immediate reconstruction, LMWH or LDH and mechanical prophylaxis can be used. By 36 hours after injury, most patients are no longer actively bleeding, and it is usually safe to administer LMWH or LDH for prophylaxis. LMWH or LDH should be administered at midnight before surgical intervention is performed.

Postoperative prophylaxis is started with warfarin (international normalized ratio [INR] goal, 2.0-3.0). Because of the risk of intraoperative embolization, all patients with pelvic fractures receiving delayed surgical reconstruction (>4 days) should undergo bilateral lower-extremity venous US or venography.

If DVT is found, the patient should receive a vena caval filter. If no DVT is found, routine postoperative prophylaxis is performed. For patients with contraindications to anticoagulation, such as intracranial bleeding, prophylactic vena caval filter placement and screening US or magnetic resonance venography (MRV) should be considered.

The incidence of sciatic or lumbosacral nerve injury in pelvic trauma is reported to be 10-15%. A higher incidence has been noted in persons with fracture dislocations with posterior pelvic instability. Anatomically, this incidence can be explained by the close relationship of the lumbar and sacral nerve roots to the sacrum and the SI joint.

In 1966, Huittinen and Slatis reviewed the nonoperative treatment of 1476 patients with unstable pelvic fractures and found a 46% rate of persistent nerve injury. [67]

Helfet et al evaluated 28 patients with 30 vertically unstable fractures of the hemipelvis and found preoperative ipsilateral neurologic injury to the sciatic lumbosacral plexus in 50% of the patients. [68] Posterior approaches and reduction led to significant unilateral changes in the somatosensory-evoked potentials (SSEPs) concurrent with manipulation of the hemipelvis for reduction. Routine careful identification and retraction of the L5 nerve root intraoperatively did not result in SSEP monitoring changes during anterior approaches.

Nonunions and malunions occur as a result of inadequate initial treatment of displaced pelvic fractures. Pain is the most common subjective symptom and is usually related to the posterior pelvic injury. Deformity is also a common symptom. Cranial displacement of the hemipelvis results in shortening of the ipsilateral extremity, which can cause the sacrum and coccyx to become more prominent and thus can be troublesome with sitting or lying down.

Matta and Saucedo reported on operative correction of 37 nonunions and malunions. [7] The procedure is technically demanding, with a complication rate of 19%. Average operating time was 7 hours, and average blood loss was 2000 mL.

A three-stage reconstruction is often required. The first stage involves an anterior approach to mobilize structures and to perform osteotomies. The patient is then repositioned, and a posterior approach is used to complete the mobilization or osteotomy. ORIF of the posterior pelvis is performed. The third stage involves a repeat anterior approach for ORIF of the anterior pelvis.


Long-Term Monitoring

Patients should undergo radiographic evaluation at 2, 6, and 12 weeks after surgery. Wounds should be evaluated at these office visits. Sutures are generally removed at 2-3 weeks. Patients with significant mobility problems should receive anticoagulation treatment with warfarin for at least 2 weeks if such treatment is not contraindicated. This should continue until patients are able to maneuver with crutches or a walker.