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Pelvic fractures—A guide to classification and management
European Journal of Radiology 74 (2010) 16–23
Contents lists available at ScienceDirect
European Journal of Radiology journal homepage: www.elsevier.com/locate/ejrad
Review
Pelvic fractures—A guide to classification and management S.J. Slater a,b,∗ , D.A. Barron a,c,1 a
Department of Radiology, Leeds Teaching Hospitals, Leeds, UK Radiology Academy, Leeds General Infirmary, Jubilee Wing, Great George St., Leeds LS1 3EX, UK c Musculoskeletal Radiology Dept, Leeds General Infirmary, Jubilee Wing, Great George St, Leeds LS1 3EX, UK b
a r t i c l e
i n f o
Article history: Received 25 January 2010 Accepted 27 January 2010 Keywords: Pelvic fracture Pelvic haemorrhage Polytrauma CT Urological injury
a b s t r a c t Pelvic fractures are common in polytrauma and continue to pose a difficult management dilemma for even the most experienced clinicians. Due to the high energy mechanisms involved, there are often multiple other injuries and many specialists may be involved. Deriving an effective management strategy relies on early diagnosis and prioritisation of the most immediately life-threatening injuries. Contrary to ATLS advice, CT can be used to facilitate this even in the haemodynamically unstable patient. This article defines the role of CT in pelvic fractures and provides an overview of fracture classification. © 2010 Elsevier Ireland Ltd. All rights reserved.
1. Introduction
2. Mechanism and resuscitation
Pelvic fractures are common in polytrauma and continue to pose difficult management dilemmas for even the most experienced clinician. Patients often sustain multiple other injuries due to the high energy mechanisms involved and management requires a multidisciplinary team. Many patients require immediate resuscitation and the standard ATLS pathway, with an ‘ABC’ approach, should be adopted. Most articles on pelvic fractures place great emphasis on fracture classification and only mention the complications in passing. In reality, the order of priority should be:
Pelvic fractures usually result from high energy trauma, although occasionally there may be a trivial mechanism of injury. In such cases, clinicians should be alert to possible underlying bone pathology. However, for the majority, the high energy mechanism results in a high rate of associated injuries. ATLS advice is thus to concentrate on the ABC (airway, breathing, circulation) method of resuscitation [1]. It is vital to look for other potentially lifethreatening injuries rather than simply concentrating on the pelvic injury.
1. Recognition of life-threatening injuries; 2. Recognition of acute injuries; 3. Fracture classification which aids in directing surgical management whilst also arousing suspicion for undetected associated injuries.
3. ATLS guidance
This review offers guidance on effective use of early imaging to identify the most pertinent injuries and provide a sound platform for which to plan management. In particular, the acute complications of pelvic fractures will be discussed with subsequent reference to specific fracture patterns. An algorithm for management is proposed incorporating the use of early CT and thereby challenging current advice from the ATLS.
∗ Corresponding author at: Radiology Academy, Leeds General Infirmary, Jubilee Wing, Great George St., Leeds LS1 3EX, UK. Tel.: +44 7718996718; fax: +44 1133922276. E-mail addresses: [email protected] (S.J. Slater), [email protected] (D.A. Barron). 1 Tel.: +44 1133923768; fax: +44 11328241. 0720-048X/$ – see front matter © 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2010.01.025
Airway; Breathing; Circulation; Disability; Exposure; Trauma radiographs (CXR, pelvis XR). 4. Acute imaging The most recent ATLS protocol (2009) advises a series of trauma radiographs (chest and pelvis) for polytrauma patients as adjuncts to the primary survey, though there is mounting opinion that they add little in the stable patient where CT will be performed anyway [2,3]. The rationale for the pelvic radiograph is because of the high risk of bleeding from pelvic fractures. Pelvic radiographs increase radiation exposure, can cause delays and have been shown to lack sensitivity in detection of fractures with figures quoted to be around 67–68% [2,3]. The role of the pelvic
S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
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Fig. 1. (a–c) A man involved in a high speed road traffic collision who was haemodynamically unstable on arrival in the emergency department. Plain radiographs showed multiple fractures through the pubic rami, sacrum and right femur (a). There was presumed bleeding secondary to this. CT revealed left extradural haemorrhage and skull fracture with intracranial air (b, arrow). There was also an unsuspected complex liver injury with active contrast extravasation (c, arrow). There was no active pelvic bleeding.
radiograph is certainly diminishing and, provided there is access to prompt CT, there is an argument to omit them from the initial management plan completely. Integrating a trauma CT (head, spine, chest, abdomen and pelvis) into the resuscitation algorithm enables a fast, early diagnosis and facilitates further management (Fig. 1a–c). This allows full evaluation of the patient, in addition to giving detailed images of the bony pelvis and any associated complications. Many patients with pelvic injuries are haemodynamically unstable. Current ATLS advice that CT is contraindicated in these patients can be challenged. At present ATLS recommends FAST scanning (focussed assessment sonography in trauma) or DPL (diagnostic peritoneal lavage) and a pelvic radiograph for such patients [1]. Neither ultrasound or DPL will demonstrate the source of the bleeding, nor can they assess the retroperitoneum or pelvic musculature and the radiograph will demonstrate only the bony anatomy. CT, by contrast, assesses all of these areas very well and very quickly. Huber-Wagner et al. showed an association between increased survival and early full body CT in polytrauma when compared to targeted body CT [6]. No adverse effects were attributable to
CT, though obviously radiation dose and intravenous contrast are potential concerns. There were several limitations to the study however, and the authors admit their findings show associations rather than causalities. Average time to CT from admission was between 35 and 46 min with the emphasis placed on an easily accessible CT scanner near the trauma room. This is vital if CT is to be used in management algorithms for unstable patients. It is proposed that CT is elevated to the ‘third tier’ alongside circulation in the ATLS algorithm for management of haemodynamically unstable patients. This holds numerous advantages: - Locating the primary source of bleeding quickly; - Allowing earlier angiography and embolisation for arterial haemorrhage; - Guiding the vascular radiologist to the likely bleeding vessel, thereby allowing selected angiography and improving sensitivity for detection of haemorrhage when compared to angiography from a larger proximal vessel. This also reduces unnecessary ‘runs’, minimising the use of contrast and radiation exposure; - Reducing the number of transfused units thereby lowering the risk of DIC and other transfusion related complications;
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S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
- Identifying other organ injuries early; - Reducing the number of unnecessary laparotomies.
5. Vascular injuries In pelvic fractures, the most common life-threatening complication is bleeding. Where there is haemodynamic instability, pelvic fractures are reported to have a high mortality rate of up to 60% [4] (Fig. 2a–c). CT can quickly and accurately reveal the presence or absence of haemorrhage with an accuracy quoted in the region of 90% [7]. Three sources of bleeding are recognised in pelvic fractures, arterial, venous and bleeding from cancellous bone. Management of these different sources varies greatly. It is generally accepted that venous and cancellous bleeding is managed by initial stabilisation of the fracture to facilitate tamponade. In such cases, close monitoring is advised as young patients in particular can appear stable or metastable despite ongoing arterial haemorrhage. Arterial bleeds are commonly from the superior gluteal and the internal pudendal arteries. The greater sciatic foramen is a common exit pathway for many pelvic vessels and any fracture involving this area incurs a higher risk of bleeding. The superior gluteal artery is at risk of laceration from the sharp fascia of the piriformis muscle as it enters the greater sciatic foramen. The internal pudendal artery also exits the pelvis here but re-enters through the lesser sciatic foramen. It is injured in anterior–posterior compression fractures where there are inferior pubic rami fractures or fractures involving the lesser sciatic foramen. Therefore the fracture location can be used to predict which artery has been injured. Artery injured
Fracture site
Superior gluteal
Greater sciatic foramen, ischial spine or tuberosity AP compression fracture involving lesser sciatic foramen, inferior pubic ramus Superior obturator foramen, superior pubic ramus, pubic acetabulum Acetabulum, injured posterior to inguinal canal Sacral foramina or posterior trans-sacral fracture Posterior fracture involving ilium or anterior SIJ’s
Internal pudendal
Obturator Femoral Lateral sacral Iliolumbar
Fig. 2. (a–c) Unstable pelvic fracture (a, arrows) with contrast extravasation on CT (b, arrow). Extensive haemorrhage was seen at angiography (c, arrow) and the vessel was subsequently embolised.
Debate has raged over the management of arterial haemorrhage for many years. Some advocate external fixation and pelvic packing for arterial and venous haemorrhage and reserve angiography only for more stable patients where ongoing bleeding is suspected [8]. Others propose external fixation followed by angiography if the patient remains unstable [9]. Some argue that external fixation provides no additional advantage over pelvic wrapping [10]. Equally, angiography has been said to be time-consuming and inhibits concurrent treatment of associated injuries [11], unlike pelvic packing in theatre [8]. One group expressed concerns over complications associated with angiography, in particular sepsis when subsequently proceeding to operative fixation of the fracture [12]. However, angiography has been utilised to good effect, with a reported success rate of 85–100% in bleeding cessation [13–16]. Despite this, several of these studies have shown a high mortality rate associated with angiography. This is partly due to the group of patients treated. Those recruited for embolisation have arterial bleeding and are also likely to have significant concurrent injuries. The success of angiographic embolisation is also highly dependant on early intervention and patients who undergo prompt embolisation have improved mortality rates [4,15]. Where there are no other life-threatening injuries there is a strong case to argue that angiography should be the intervention of choice [10,16,17].
S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
This then gives the clinician the problem of working out as soon as possible which type of bleeding the patient has got. Clearly early recognition of arterial bleeding is desirable as in these cases angiography and embolisation should precede all other interventions. Integrating CT into the resuscitation protocol therefore will not only serve to identify all of the patient’s injuries but can potentially differentiate the different types of pelvic bleed [18]. To achieve this both arterial and portal venous phase imaging should be employed where pelvic bleeding is suspected. Contrast extravasation identified on both phases is likely to be arterial whereas extravasation seen only on the portal venous phase is consistent with venous bleeding. Therefore if the patient has multiple other injuries then the operating room may well be the preferred treatment option. The same applies to venous and cancellous pelvic bleeds. If however there are isolated arterial bleeds then clearly angiography, where available, if preferable. A new management algorithm is proposed for pelvic fractures incorporating early CT (Table 1).
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6. Urological injury This is a well recognised complication particularly where there is separation of the pubic symphysis or a fractured pubic ramus. Injuries to the bladder range from contusions to bladder rupture. Most bladder ruptures are extraperitoneal with intraperitoneal ruptures resulting from blunt trauma to a distended bladder or iatrogenic causes. Occasionally, bladder injury may be suspected on plain radiography when there is a ‘pear-shaped’ bladder, with a paralytic ileus and loss of obturator fat planes. However, the diagnosis is confirmed by a retrograde cystogram or preferably CT cystography. Typically, a retrograde cystogram will depict a ‘flame-shaped’ contrast extravasation into the perivesical fat and occasionally into the thigh or anterior abdominal wall. In intraperitoneal ruptures, contrast will extravasate into the paracolic gutters and will be seen outlining small bowel loops. On CT, it is important to distinguish urinary contrast extravasation from vascular extravasation. For this reason, cystography should be performed after intravenous
Table 1 A basic algorithm for management of pelvic fractures. Note that this strategy may be inappropriate if there are other life-threatening injuries also requiring urgent attention.
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ciated injuries. Many studies have attempted to predict the risk of haemorrhage according to fracture pattern [4,20]. However, whilst unstable pelvic fractures are more frequently associated with haemorrhage, fracture pattern cannot be used to absolutely predict haemorrhage [10]. 9. Pelvic ring fractures The pelvis is considered to be a ring structure comprised of three bones, the sacrum and two innominate bones. The posterior ring includes the sacrum, SI joints and iliac bones, whilst the anterior ring is comprised of the pubic bones and symphysis. The SI joints can be divided into anterior and posterior and are held together by the anterior and posterior sacroiliac ligaments. The posterior sacroiliac ligaments are the strongest in the body and are most important in maintaining pelvic stability. The sacrotuberous and sacrospinous ligaments provide additional support posteriorly. Conversely, the pubic symphysis anteriorly is weaker and more easily ruptured. Two accepted classification systems exist, the Young–Burgess and Tile systems [21,22]. The Young–Burgess system classifies injuries according to the mechanism and severity. The Tile system arranges fractures into three main groups, stable, partially unstable and completely unstable. For the purposes of this review, the Young–Burgess system will be considered. There are three main patterns of injury: • AP compression; • Lateral compression; • Vertical shear. 10. AP compression
Fig. 3. (a and b) Window cleaner who fell from a ladder. Unstable pelvic fracture with extraperitoneal contrast extravasation on retrograde cystogram indicating bladder rupture.
contrast CT or angiography to avoid obscuring any vascular extravasation (Fig. 3a and b). Urethral injuries are more common in men and typically occur in the membranous urethra in the region of the urogenital diaphragm. A retrograde urethrogram can be performed if there is clinical suspicion. Clearly, this should be performed before attempts at urinary catheterisation if there is any concern for urethral trauma. 7. Neurological injury Neurological injuries may be an early or late complication of pelvic fractures but are often overlooked in the busy trauma setting. Bladder, bowel and erectile dysfunction are some of the potentially devastating consequences, which are often permanent. The reported prevalence of neurological deficit following pelvic fracture is approximately 10% [19]. The fracture pattern obviously determines both the risk and nature of neurological injury. For example transverse sacral fractures can cause intraspinal and intraforaminal nerve root injury, as discussed later. Sciatic nerve injuries may occur if the fracture involves the greater sciatic notch or the posterior acetabulum. 8. Fracture classification Delineating the exact nature of the fracture is useful both for the orthopaedic surgeon and also in raising suspicion for asso-
AP compression fractures cause external rotation of one or both hemipelves, causing the iliac wings to move outwards. These injuries are characterised by pubic diastasis, either at the symphysis or through sagittal ramal fractures. Associated injuries may include sacroiliac joint diastasis and, less commonly, sacral fractures. AP compression injuries cause an increased pelvic volume with any resulting haemorrhage unlikely to tamponade spontaneously. Pelvic wrapping should therefore be a priority in early management. According to the Young–Burgess system, these injuries are classified as follows: AC 1: Pubic diastasis <2.5 cm, either at the symphysis or through sagittal ramal fractures; AC 2: Pubic diastasis >2.5 cm and anterior SIJ disruption; AC 3: Pubic diastasis >2.5 cm, anterior and posterior SIJ disruption. AC 1 injuries are stable. AC 2 injuries are vertically stable but rotationally unstable due to anterior SIJ disruption—this is the classic ‘open-book’ fracture, where the intact posterior ligaments act as the ‘binding’ (Fig. 4). AC 3 injuries involve disruption of the posterior ligaments causing both vertical and rotational instability. 11. Lateral compression This is the most common type of pelvic fracture [22]. Lateral forces cause internal rotation of the hemipelvis. This results in coronal ramal fractures, contralateral SIJ disruption and central acetabular fractures. Unlike AP compression fractures, lateral compression injuries have a high association with sacral fractures, reported to be in the region of 88% [22].
S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
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Fig. 4. AC type 2 fracture. Note pubic diastasis but intact posterior ligaments. This is an ‘open book’ fracture.
Pelvic volume tends to reduce in lateral compression fractures, with haemorrhage more likely to tamponade spontaneously. Young–Burgess classification is as follows: LC 1: Ipsilateral ‘buckle’ sacral and coronal pubic rami fractures; LC 2: Type 1 + ipsilateral iliac wing fracture or posterior SIJ disruption; LC 3: Type 2 + external rotation of the contralateral hemipelvis ± contralateral saggital ramal fractures. Type 1 fractures are stable, types 2 and 3 are rotationally unstable but vertically stable owing to the intact posterior sacroiliac ligaments (Fig. 5a and b). 12. Vertical shear Vertical shear injuries are vertically and rotationally unstable owing to disruption of the posterior ligaments. Often the vertical force is the femur, which causes vertically orientated ramal fractures anteriorly and ligamentous injury posteriorly. The hemipelvis is shifted cranially. A subtle sign of instability is a fracture of the tip of the transverse process of L5, caused by avulsion of the iliolumbar ligament. There is a high rate of associated injuries to the torso and spine and a high rate of haemodynamic instability (Fig. 6).
Fig. 5. (a and b) LC2 fracture. Note right sided pubic rami fractures and ipsilateral sacral buckle fracture. The sacral fracture is more easily identified on CT (b, arrow).
Zone 2: Involving the neuroforamina which can cause unilateral sacral anaesthesia. No involvement of the central sacral canal. Zone 3: Involving the body of sacrum. This injury has a high association with neurological compromise (approx. 56% [23]), and may result in cauda equina syndrome. Transverse fractures are less common, but can also result from high energy trauma. Transverse fractures above S4 have a high rate
13. Complex fractures Not uncommonly, pelvic fractures may display features of more than one pattern of injury but the same rules of stability apply. 14. Sacral fractures Commonly overlooked, sacral fractures should be considered as part of the pelvic ring. Notoriously difficult to visualise on plain radiography, these fractures have a high association of potentially devastating neurological injury and should not be missed. Depending on the exact site of fracture, the rate of complication differs greatly. A classification system has been devised to help predict the risk of neurological impairment [23]: Zone 1: Involving the sacral ala lateral to sacral foramina. This can cause L5 nerve root impingement, with approximately 6% sustaining neurological injury [23].
Fig. 6. Vertical shear fracture. Vertically orientated pubic rami fractures and cranial displacement of the right hemipelvis. This is vertically and rotationally unstable.
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Fig. 8. Coronal STIR sequence MRI. ‘Honda sign’ (arrows) demonstrating sacral insufficiency fractures in an elderly female. Note the typical vertical and horizontal high intensity in the sacral ala bilaterally.
of associated neurological injury, whereas the risk below this level is low. These fractures can cause intraspinal and intraforaminal nerve root compromise (Fig. 7a and b). Rarely, there may be a U-shaped sacral fracture. Highly unstable, this involves longitudinal fractures through the foramina bilaterally and a transverse fracture with subsequent spino-pelvic dissociation. As a result, there is a high rate of associated neurological injury. In the presence of low impact injury, there should be high suspicion for an insufficiency fracture. Modern multi-detector CT will identify most sacral fractures. However, some are more easily identified on MRI where one may see the classic ‘Honda sign’ (Fig. 8). 15. Conclusion Pelvic fractures result from high energy trauma and are often associated with multiple injuries. The key to management lies in early detection of life-threatening and acute injuries. A common mistake in polytrauma is to diagnose and manage an unstable pelvic fracture before imaging the whole body. Multislice CT provides a reliable and rapid diagnosis even in the haemodynamically unstable patient and should not be delayed for management of the fracture. CT also offers detailed imaging of the bony pelvis. Knowledge of pelvic fracture patterns is valuable for surgical planning and reminding radiologists to reassess for potential complications. References
Fig. 7. (a and b) Sacral fracture in an alcoholic man who sat down too hard! This low energy mechanism of injury raises concern for underlying osteopenia. These fractures can be difficult to detect on AP views, but this particular injury was more obvious on the lateral view (b, arrow).
[1] American College of Surgeons Committee on Trauma. ATLS student course manual. 8th ed. Chicago: American College of Surgeons Committee on Trauma; 2008. [2] Hilty MP, Behrendt I, Benneker LM, et al. Pelvic radiography in ATLS algorithms: adiminishing role? World J Emerg Surg 2008;3:11. [3] Guillamondegui OD, Pryor JP, Gracias VH, et al. Pelvic radiography in blunt trauma resuscitation: a diminishing role. J Trauma 2002;53(6):1043–7. [4] Eastridge BJ, Starr A, Minei JP, et al. The importance of fracture pattern in guiding therapeutic decision-making in patients with haemorrhagic shock and pelvic ring disruptions. J Trauma 2002;53(3):446–50. [6] Huber-Wagner S, Lefering R, Qvick LM, et al. Effect of whole body CT during trauma resuscitation on survival: a retrospective multicentre study. Lancet 2009;373(9673):1455–61. [7] Cerva Jr DS, Mirvis SE, Shanmuganathan K, et al. Detection of bleeding in patients with major pelvic fractures: value of contrast enhanced CT. Am J Roentgenol 1996;166:131–5. [8] Gansslen A, Giannoudis P, Pape HC. Hemorrhage in pelvic fracture: who needs angiography? Curr Opin Crit Care 2003;9:515–23.
S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23 [9] Cook RE, Keating JF, Gillespie I. The role of angiography in the management of haemorrhage from major fractures of the pelvis. J Bone Joint Surg (Br) 2002;84:178–82. [10] Dyer GSM, Vrahas MS. Review of the pathophysiology and acute management of haemorrhage in pelvic fracture. Injury 2006;37:602–13. [11] Blackmore CC, Cummings P, Jurkovich GJ, et al. Predicting major haemorrhage in patients with pelvic fracture. J Trauma 2006;61(2):346–52. [12] Perez JV, Hughes TM, Bowers K. Angiographic embolisation in pelvic fracture. Injury 1998;29:187–91. [13] Fangio P, Asehnoune K, Edouard A, et al. Early embolisation and vasopressor administration for management of life-threatening hemorrhage from pelvic fracture. J Trauma 2005;58(5):978–84. [14] Velmahos GC, Konstantinos KG, Vassiliu P, et al. A prospective study on the safety and efficacy of angiographic embolisation for pelvic and visceral injuries. J Trauma 2002;52(2):303–8. [15] Agolini SF, Shah K, Jaffe J, et al. Arterial embolization is a rapid and effective technique for controlling pelvic fracture haemorrhage. J Trauma 1997;43:395–9. [16] Panetta T, Sclafani SJ, Goldstein AS, et al. Percutaneous transcatheter embolization for massive bleeding from pelvic fractures. J Trauma 1985;25:1021–9.
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[17] Ben-Menachem Y, Coldwell DM, Young JW, Burgess AR. Hemorrhage associated with pelvic fractures: causes, diagnosis and emergent management. Am J Roentgenol 1991;157:1005–14. [18] Anderson SW, Soto JA, Lucey BC, et al. Blunt trauma: feasibility and clinical utility of pelvic CT angiography performed with 64 detector row CT. Radiology 2008;245(2):410–9. [19] Rai SK, Far RF, Ghovanlou B. Neurologic deficits associated with sacral wing fractures. Orthopedics 1990;13(12):1363–6. [20] Dalal SA, Burgess AR, Siegel JH, et al. Pelvic fracture pattern in multiple trauma; classification by mechanism is key to pattern of organ injury, resuscitation requirements and outcome. J Trauma 1989;29(7):981–1000. [21] Tile M. Pelvic ring fractures: should they be fixed? J Bone Joint Surg 1988;70B:1–12. [22] Young JW, Burgess AR, Brumback RJ, Poka A. Pelvic fractures: value of plain radiography in early assessment and management. Radiology 1986;160(2):445–51. [23] Denis F, Davis S, Comfort T. Sacral fractures: an important problem. Retrospective analysis of 236 cases. Clin Orthop Relat Res 1988;227:67–81.
Contents lists available at ScienceDirect
European Journal of Radiology journal homepage: www.elsevier.com/locate/ejrad
Review
Pelvic fractures—A guide to classification and management S.J. Slater a,b,∗ , D.A. Barron a,c,1 a
Department of Radiology, Leeds Teaching Hospitals, Leeds, UK Radiology Academy, Leeds General Infirmary, Jubilee Wing, Great George St., Leeds LS1 3EX, UK c Musculoskeletal Radiology Dept, Leeds General Infirmary, Jubilee Wing, Great George St, Leeds LS1 3EX, UK b
a r t i c l e
i n f o
Article history: Received 25 January 2010 Accepted 27 January 2010 Keywords: Pelvic fracture Pelvic haemorrhage Polytrauma CT Urological injury
a b s t r a c t Pelvic fractures are common in polytrauma and continue to pose a difficult management dilemma for even the most experienced clinicians. Due to the high energy mechanisms involved, there are often multiple other injuries and many specialists may be involved. Deriving an effective management strategy relies on early diagnosis and prioritisation of the most immediately life-threatening injuries. Contrary to ATLS advice, CT can be used to facilitate this even in the haemodynamically unstable patient. This article defines the role of CT in pelvic fractures and provides an overview of fracture classification. © 2010 Elsevier Ireland Ltd. All rights reserved.
1. Introduction
2. Mechanism and resuscitation
Pelvic fractures are common in polytrauma and continue to pose difficult management dilemmas for even the most experienced clinician. Patients often sustain multiple other injuries due to the high energy mechanisms involved and management requires a multidisciplinary team. Many patients require immediate resuscitation and the standard ATLS pathway, with an ‘ABC’ approach, should be adopted. Most articles on pelvic fractures place great emphasis on fracture classification and only mention the complications in passing. In reality, the order of priority should be:
Pelvic fractures usually result from high energy trauma, although occasionally there may be a trivial mechanism of injury. In such cases, clinicians should be alert to possible underlying bone pathology. However, for the majority, the high energy mechanism results in a high rate of associated injuries. ATLS advice is thus to concentrate on the ABC (airway, breathing, circulation) method of resuscitation [1]. It is vital to look for other potentially lifethreatening injuries rather than simply concentrating on the pelvic injury.
1. Recognition of life-threatening injuries; 2. Recognition of acute injuries; 3. Fracture classification which aids in directing surgical management whilst also arousing suspicion for undetected associated injuries.
3. ATLS guidance
This review offers guidance on effective use of early imaging to identify the most pertinent injuries and provide a sound platform for which to plan management. In particular, the acute complications of pelvic fractures will be discussed with subsequent reference to specific fracture patterns. An algorithm for management is proposed incorporating the use of early CT and thereby challenging current advice from the ATLS.
∗ Corresponding author at: Radiology Academy, Leeds General Infirmary, Jubilee Wing, Great George St., Leeds LS1 3EX, UK. Tel.: +44 7718996718; fax: +44 1133922276. E-mail addresses: [email protected] (S.J. Slater), [email protected] (D.A. Barron). 1 Tel.: +44 1133923768; fax: +44 11328241. 0720-048X/$ – see front matter © 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2010.01.025
Airway; Breathing; Circulation; Disability; Exposure; Trauma radiographs (CXR, pelvis XR). 4. Acute imaging The most recent ATLS protocol (2009) advises a series of trauma radiographs (chest and pelvis) for polytrauma patients as adjuncts to the primary survey, though there is mounting opinion that they add little in the stable patient where CT will be performed anyway [2,3]. The rationale for the pelvic radiograph is because of the high risk of bleeding from pelvic fractures. Pelvic radiographs increase radiation exposure, can cause delays and have been shown to lack sensitivity in detection of fractures with figures quoted to be around 67–68% [2,3]. The role of the pelvic
S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
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Fig. 1. (a–c) A man involved in a high speed road traffic collision who was haemodynamically unstable on arrival in the emergency department. Plain radiographs showed multiple fractures through the pubic rami, sacrum and right femur (a). There was presumed bleeding secondary to this. CT revealed left extradural haemorrhage and skull fracture with intracranial air (b, arrow). There was also an unsuspected complex liver injury with active contrast extravasation (c, arrow). There was no active pelvic bleeding.
radiograph is certainly diminishing and, provided there is access to prompt CT, there is an argument to omit them from the initial management plan completely. Integrating a trauma CT (head, spine, chest, abdomen and pelvis) into the resuscitation algorithm enables a fast, early diagnosis and facilitates further management (Fig. 1a–c). This allows full evaluation of the patient, in addition to giving detailed images of the bony pelvis and any associated complications. Many patients with pelvic injuries are haemodynamically unstable. Current ATLS advice that CT is contraindicated in these patients can be challenged. At present ATLS recommends FAST scanning (focussed assessment sonography in trauma) or DPL (diagnostic peritoneal lavage) and a pelvic radiograph for such patients [1]. Neither ultrasound or DPL will demonstrate the source of the bleeding, nor can they assess the retroperitoneum or pelvic musculature and the radiograph will demonstrate only the bony anatomy. CT, by contrast, assesses all of these areas very well and very quickly. Huber-Wagner et al. showed an association between increased survival and early full body CT in polytrauma when compared to targeted body CT [6]. No adverse effects were attributable to
CT, though obviously radiation dose and intravenous contrast are potential concerns. There were several limitations to the study however, and the authors admit their findings show associations rather than causalities. Average time to CT from admission was between 35 and 46 min with the emphasis placed on an easily accessible CT scanner near the trauma room. This is vital if CT is to be used in management algorithms for unstable patients. It is proposed that CT is elevated to the ‘third tier’ alongside circulation in the ATLS algorithm for management of haemodynamically unstable patients. This holds numerous advantages: - Locating the primary source of bleeding quickly; - Allowing earlier angiography and embolisation for arterial haemorrhage; - Guiding the vascular radiologist to the likely bleeding vessel, thereby allowing selected angiography and improving sensitivity for detection of haemorrhage when compared to angiography from a larger proximal vessel. This also reduces unnecessary ‘runs’, minimising the use of contrast and radiation exposure; - Reducing the number of transfused units thereby lowering the risk of DIC and other transfusion related complications;
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S.J. Slater, D.A. Barron / European Journal of Radiology 74 (2010) 16–23
- Identifying other organ injuries early; - Reducing the number of unnecessary laparotomies.
5. Vascular injuries In pelvic fractures, the most common life-threatening complication is bleeding. Where there is haemodynamic instability, pelvic fractures are reported to have a high mortality rate of up to 60% [4] (Fig. 2a–c). CT can quickly and accurately reveal the presence or absence of haemorrhage with an accuracy quoted in the region of 90% [7]. Three sources of bleeding are recognised in pelvic fractures, arterial, venous and bleeding from cancellous bone. Management of these different sources varies greatly. It is generally accepted that venous and cancellous bleeding is managed by initial stabilisation of the fracture to facilitate tamponade. In such cases, close monitoring is advised as young patients in particular can appear stable or metastable despite ongoing arterial haemorrhage. Arterial bleeds are commonly from the superior gluteal and the internal pudendal arteries. The greater sciatic foramen is a common exit pathway for many pelvic vessels and any fracture involving this area incurs a higher risk of bleeding. The superior gluteal artery is at risk of laceration from the sharp fascia of the piriformis muscle as it enters the greater sciatic foramen. The internal pudendal artery also exits the pelvis here but re-enters through the lesser sciatic foramen. It is injured in anterior–posterior compression fractures where there are inferior pubic rami fractures or fractures involving the lesser sciatic foramen. Therefore the fracture location can be used to predict which artery has been injured. Artery injured
Fracture site
Superior gluteal
Greater sciatic foramen, ischial spine or tuberosity AP compression fracture involving lesser sciatic foramen, inferior pubic ramus Superior obturator foramen, superior pubic ramus, pubic acetabulum Acetabulum, injured posterior to inguinal canal Sacral foramina or posterior trans-sacral fracture Posterior fracture involving ilium or anterior SIJ’s
Internal pudendal
Obturator Femoral Lateral sacral Iliolumbar
Fig. 2. (a–c) Unstable pelvic fracture (a, arrows) with contrast extravasation on CT (b, arrow). Extensive haemorrhage was seen at angiography (c, arrow) and the vessel was subsequently embolised.
Debate has raged over the management of arterial haemorrhage for many years. Some advocate external fixation and pelvic packing for arterial and venous haemorrhage and reserve angiography only for more stable patients where ongoing bleeding is suspected [8]. Others propose external fixation followed by angiography if the patient remains unstable [9]. Some argue that external fixation provides no additional advantage over pelvic wrapping [10]. Equally, angiography has been said to be time-consuming and inhibits concurrent treatment of associated injuries [11], unlike pelvic packing in theatre [8]. One group expressed concerns over complications associated with angiography, in particular sepsis when subsequently proceeding to operative fixation of the fracture [12]. However, angiography has been utilised to good effect, with a reported success rate of 85–100% in bleeding cessation [13–16]. Despite this, several of these studies have shown a high mortality rate associated with angiography. This is partly due to the group of patients treated. Those recruited for embolisation have arterial bleeding and are also likely to have significant concurrent injuries. The success of angiographic embolisation is also highly dependant on early intervention and patients who undergo prompt embolisation have improved mortality rates [4,15]. Where there are no other life-threatening injuries there is a strong case to argue that angiography should be the intervention of choice [10,16,17].
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This then gives the clinician the problem of working out as soon as possible which type of bleeding the patient has got. Clearly early recognition of arterial bleeding is desirable as in these cases angiography and embolisation should precede all other interventions. Integrating CT into the resuscitation protocol therefore will not only serve to identify all of the patient’s injuries but can potentially differentiate the different types of pelvic bleed [18]. To achieve this both arterial and portal venous phase imaging should be employed where pelvic bleeding is suspected. Contrast extravasation identified on both phases is likely to be arterial whereas extravasation seen only on the portal venous phase is consistent with venous bleeding. Therefore if the patient has multiple other injuries then the operating room may well be the preferred treatment option. The same applies to venous and cancellous pelvic bleeds. If however there are isolated arterial bleeds then clearly angiography, where available, if preferable. A new management algorithm is proposed for pelvic fractures incorporating early CT (Table 1).
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6. Urological injury This is a well recognised complication particularly where there is separation of the pubic symphysis or a fractured pubic ramus. Injuries to the bladder range from contusions to bladder rupture. Most bladder ruptures are extraperitoneal with intraperitoneal ruptures resulting from blunt trauma to a distended bladder or iatrogenic causes. Occasionally, bladder injury may be suspected on plain radiography when there is a ‘pear-shaped’ bladder, with a paralytic ileus and loss of obturator fat planes. However, the diagnosis is confirmed by a retrograde cystogram or preferably CT cystography. Typically, a retrograde cystogram will depict a ‘flame-shaped’ contrast extravasation into the perivesical fat and occasionally into the thigh or anterior abdominal wall. In intraperitoneal ruptures, contrast will extravasate into the paracolic gutters and will be seen outlining small bowel loops. On CT, it is important to distinguish urinary contrast extravasation from vascular extravasation. For this reason, cystography should be performed after intravenous
Table 1 A basic algorithm for management of pelvic fractures. Note that this strategy may be inappropriate if there are other life-threatening injuries also requiring urgent attention.
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ciated injuries. Many studies have attempted to predict the risk of haemorrhage according to fracture pattern [4,20]. However, whilst unstable pelvic fractures are more frequently associated with haemorrhage, fracture pattern cannot be used to absolutely predict haemorrhage [10]. 9. Pelvic ring fractures The pelvis is considered to be a ring structure comprised of three bones, the sacrum and two innominate bones. The posterior ring includes the sacrum, SI joints and iliac bones, whilst the anterior ring is comprised of the pubic bones and symphysis. The SI joints can be divided into anterior and posterior and are held together by the anterior and posterior sacroiliac ligaments. The posterior sacroiliac ligaments are the strongest in the body and are most important in maintaining pelvic stability. The sacrotuberous and sacrospinous ligaments provide additional support posteriorly. Conversely, the pubic symphysis anteriorly is weaker and more easily ruptured. Two accepted classification systems exist, the Young–Burgess and Tile systems [21,22]. The Young–Burgess system classifies injuries according to the mechanism and severity. The Tile system arranges fractures into three main groups, stable, partially unstable and completely unstable. For the purposes of this review, the Young–Burgess system will be considered. There are three main patterns of injury: • AP compression; • Lateral compression; • Vertical shear. 10. AP compression
Fig. 3. (a and b) Window cleaner who fell from a ladder. Unstable pelvic fracture with extraperitoneal contrast extravasation on retrograde cystogram indicating bladder rupture.
contrast CT or angiography to avoid obscuring any vascular extravasation (Fig. 3a and b). Urethral injuries are more common in men and typically occur in the membranous urethra in the region of the urogenital diaphragm. A retrograde urethrogram can be performed if there is clinical suspicion. Clearly, this should be performed before attempts at urinary catheterisation if there is any concern for urethral trauma. 7. Neurological injury Neurological injuries may be an early or late complication of pelvic fractures but are often overlooked in the busy trauma setting. Bladder, bowel and erectile dysfunction are some of the potentially devastating consequences, which are often permanent. The reported prevalence of neurological deficit following pelvic fracture is approximately 10% [19]. The fracture pattern obviously determines both the risk and nature of neurological injury. For example transverse sacral fractures can cause intraspinal and intraforaminal nerve root injury, as discussed later. Sciatic nerve injuries may occur if the fracture involves the greater sciatic notch or the posterior acetabulum. 8. Fracture classification Delineating the exact nature of the fracture is useful both for the orthopaedic surgeon and also in raising suspicion for asso-
AP compression fractures cause external rotation of one or both hemipelves, causing the iliac wings to move outwards. These injuries are characterised by pubic diastasis, either at the symphysis or through sagittal ramal fractures. Associated injuries may include sacroiliac joint diastasis and, less commonly, sacral fractures. AP compression injuries cause an increased pelvic volume with any resulting haemorrhage unlikely to tamponade spontaneously. Pelvic wrapping should therefore be a priority in early management. According to the Young–Burgess system, these injuries are classified as follows: AC 1: Pubic diastasis <2.5 cm, either at the symphysis or through sagittal ramal fractures; AC 2: Pubic diastasis >2.5 cm and anterior SIJ disruption; AC 3: Pubic diastasis >2.5 cm, anterior and posterior SIJ disruption. AC 1 injuries are stable. AC 2 injuries are vertically stable but rotationally unstable due to anterior SIJ disruption—this is the classic ‘open-book’ fracture, where the intact posterior ligaments act as the ‘binding’ (Fig. 4). AC 3 injuries involve disruption of the posterior ligaments causing both vertical and rotational instability. 11. Lateral compression This is the most common type of pelvic fracture [22]. Lateral forces cause internal rotation of the hemipelvis. This results in coronal ramal fractures, contralateral SIJ disruption and central acetabular fractures. Unlike AP compression fractures, lateral compression injuries have a high association with sacral fractures, reported to be in the region of 88% [22].
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Fig. 4. AC type 2 fracture. Note pubic diastasis but intact posterior ligaments. This is an ‘open book’ fracture.
Pelvic volume tends to reduce in lateral compression fractures, with haemorrhage more likely to tamponade spontaneously. Young–Burgess classification is as follows: LC 1: Ipsilateral ‘buckle’ sacral and coronal pubic rami fractures; LC 2: Type 1 + ipsilateral iliac wing fracture or posterior SIJ disruption; LC 3: Type 2 + external rotation of the contralateral hemipelvis ± contralateral saggital ramal fractures. Type 1 fractures are stable, types 2 and 3 are rotationally unstable but vertically stable owing to the intact posterior sacroiliac ligaments (Fig. 5a and b). 12. Vertical shear Vertical shear injuries are vertically and rotationally unstable owing to disruption of the posterior ligaments. Often the vertical force is the femur, which causes vertically orientated ramal fractures anteriorly and ligamentous injury posteriorly. The hemipelvis is shifted cranially. A subtle sign of instability is a fracture of the tip of the transverse process of L5, caused by avulsion of the iliolumbar ligament. There is a high rate of associated injuries to the torso and spine and a high rate of haemodynamic instability (Fig. 6).
Fig. 5. (a and b) LC2 fracture. Note right sided pubic rami fractures and ipsilateral sacral buckle fracture. The sacral fracture is more easily identified on CT (b, arrow).
Zone 2: Involving the neuroforamina which can cause unilateral sacral anaesthesia. No involvement of the central sacral canal. Zone 3: Involving the body of sacrum. This injury has a high association with neurological compromise (approx. 56% [23]), and may result in cauda equina syndrome. Transverse fractures are less common, but can also result from high energy trauma. Transverse fractures above S4 have a high rate
13. Complex fractures Not uncommonly, pelvic fractures may display features of more than one pattern of injury but the same rules of stability apply. 14. Sacral fractures Commonly overlooked, sacral fractures should be considered as part of the pelvic ring. Notoriously difficult to visualise on plain radiography, these fractures have a high association of potentially devastating neurological injury and should not be missed. Depending on the exact site of fracture, the rate of complication differs greatly. A classification system has been devised to help predict the risk of neurological impairment [23]: Zone 1: Involving the sacral ala lateral to sacral foramina. This can cause L5 nerve root impingement, with approximately 6% sustaining neurological injury [23].
Fig. 6. Vertical shear fracture. Vertically orientated pubic rami fractures and cranial displacement of the right hemipelvis. This is vertically and rotationally unstable.
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Fig. 8. Coronal STIR sequence MRI. ‘Honda sign’ (arrows) demonstrating sacral insufficiency fractures in an elderly female. Note the typical vertical and horizontal high intensity in the sacral ala bilaterally.
of associated neurological injury, whereas the risk below this level is low. These fractures can cause intraspinal and intraforaminal nerve root compromise (Fig. 7a and b). Rarely, there may be a U-shaped sacral fracture. Highly unstable, this involves longitudinal fractures through the foramina bilaterally and a transverse fracture with subsequent spino-pelvic dissociation. As a result, there is a high rate of associated neurological injury. In the presence of low impact injury, there should be high suspicion for an insufficiency fracture. Modern multi-detector CT will identify most sacral fractures. However, some are more easily identified on MRI where one may see the classic ‘Honda sign’ (Fig. 8). 15. Conclusion Pelvic fractures result from high energy trauma and are often associated with multiple injuries. The key to management lies in early detection of life-threatening and acute injuries. A common mistake in polytrauma is to diagnose and manage an unstable pelvic fracture before imaging the whole body. Multislice CT provides a reliable and rapid diagnosis even in the haemodynamically unstable patient and should not be delayed for management of the fracture. CT also offers detailed imaging of the bony pelvis. Knowledge of pelvic fracture patterns is valuable for surgical planning and reminding radiologists to reassess for potential complications. References
Fig. 7. (a and b) Sacral fracture in an alcoholic man who sat down too hard! This low energy mechanism of injury raises concern for underlying osteopenia. These fractures can be difficult to detect on AP views, but this particular injury was more obvious on the lateral view (b, arrow).
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