Anaesthesia for the management of traumatic pelvic fractures

Learning objectives.

By reading this article you should be able to:

• •Discuss the anatomy of the pelvis and classify fractures of the pelvis.
• •Explain the sources of pelvic bleeding and discuss management options.
• •Outline the surgical approaches to pelvic fixation.
• •Recognise the risk of thromboembolism and suggest methods of reducing its risk.

Key points.

• •Traumatic pelvic fractures are associated with major haemorrhage and the early application of a pelvic binder can be life-saving.
• •Pelvic stability should not be mechanically tested, and log rolling should be avoided to prevent clot disruption.
• •Associated injuries are common and may dictate initial management.
• •Surgical approaches can be varied and the patient may lie supine, lateral, or prone for surgery.
• •Early initiation of thromboprophylaxis and surgical intervention helps reduce morbidity from venous thromboembolism.

The management of patients with traumatic pelvic fractures remains a significant challenge requiring rapid evaluation and intervention from a multidisciplinary team. Typical mechanisms of injury include motor vehicle accidents, pedestrians struck by a motor vehicle, falls from height, and crush injuries. The overall mortality rate for all types of pelvic fractures ranges from 5% to 15% and increases considerably in those who are haemodynamically unstable on presentation.1, 2 Increasing age, open pelvic fractures, and severe head, chest, or intra-abdominal injury also increase the risk of mortality. Haemorrhage is the leading cause of death in these patients with bleeding from additional injuries being equally as likely to cause death as pelvic haemorrhage. Associated traumatic brain injuries are common and account for approximately 20% of early deaths.³ The long-term implications include physical and mental health problems, which lead to a substantially reduced quality of life for survivors and significant socioeconomic implications for society.

The key priorities in the management of high-energy pelvic fractures are patient resuscitation, fracture stabilisation, and definitive fixation. This article aims to detail the anaesthetic management of these patients through their hospital journey from presentation to postoperative care. It also outlines the function of the pelvis, relevant anatomy, and classification of pelvic injuries.

Functions of the pelvis

The term ‘pelvis’ is derived from the Latin word for ‘basin’ owing to its bowl-like structure at the base of the axial skeleton. It forms the junction between the upper body and lower limbs through which many vital structures pass. The functions of the pelvis include:

• (i)transmission of weight from the axial skeleton to the lower appendicular skeleton;
• (ii)attachment point for various muscles and ligaments to aid in locomotion and maintenance of balance;
• (iii)protection of the organs of reproduction, bladder, and small bowel.

Anatomy

The bony pelvis is a structure comprising paired innominate bones, the sacrum, and the coccyx (Fig. 1). The large innominate bone is made up of individual bones that fuse together to form the acetabulum by adulthood. The ilium is the largest of the three and forms the superior aspect of the innominate bone. The ischium forms the posterior–inferior portion of the innominate bone and is divisible into three sections: the superior ramus, body, and inferior ramus. The pubis forms the anterior portion of the innominate bone and is also divided into the body, superior ramus, and inferior ramus. The sacrum is a triangular bone formed by the fusion of five sacral vertebrae and forms the posterior wall of the pelvis.

Fig 1.

Anatomy of the pelvis. Anterior (left) and posterior (right) views. Reproduced from https://commons.wikimedia.org/wiki/File:Blausen_0723_Pelvis.png#file with permission under the Wikimedia Creative Commons attribution licence.⁴

The pelvic ring

When considering the injury mechanism, it is useful to view the pelvis as a ring-like structure formed by the sacrum and the paired innominate bones. The stability of this ring depends upon its surrounding ligamentous construction. A strong network of stabilising muscles and ligaments limit the mobility of the sacroiliac joint, of which the most powerful is the interosseous sacroiliac ligament. The posterior sacroiliac ligaments are significantly stronger than the anterior sacroiliac ligaments, which can be more easily disrupted. A series of ligaments reinforce the pubic symphysis, but it remains the weakest point of the pelvic ring.

Classification of pelvic fractures

The classification of fractures of the pelvis can be based on mechanism of injury or pelvic stability. The most commonly used classification system is the one devised by Young and Burgess (Fig. 2), which is based upon the direction of the force causing injury.⁵

• (i)Anteroposterior (AP) compression—typically caused by a head-on collision. This results in widening of the pubic symphysis with or without disruption of elements of the sacroiliac joint.
• (ii)Lateral compression—typically caused when hit from one side. This results in internal rotation of one side of the pelvis and a characteristic anterior pubic rami fracture.
• (iii)Vertical shear—typically caused by a fall from height or axial loading of an extended limb on collision. This results in complete disruption of the pelvic ring with superior displacement of the hemipelvis.
• (iv)Combined mechanism—accommodates injuries resulting from a combination of the above forces.

Fig 2.

Young and Burgess classification of pelvic fractures.⁵ AP, anteroposterior compression; LC, lateral compression; VS, vertical shear.

The femoral head will frequently dislocate, usually posteriorly, or be driven into the pelvis resulting in fractures of the acetabulum and adjacent portions of the pelvis. This is more commonly seen with lateral compression and vertical shear injuries.

Stability of the pelvic ring

Pelvic ring injuries can also be described as stable or unstable. Stable fractures occur with a low energy mechanism of injury and tend to heal well. Unstable injuries are further divided into those with rotational instability only, or those with rotational and vertical instability. They are usually secondary to a high impact injury and more likely to be associated with haemorrhage. Rotational instability allows opening of the pelvis (like a book) increasing the volume and limiting its ability to tamponade. Vertical instability allows vertical translation of the hemipelvis leading to extensive soft tissue disruption and severe haemorrhage.

Initial management of the presenting patient

The majority of pelvic fractures present to major trauma centres unless the ambulance team divert to the nearest hospital because of cardiac arrest on presentation or in transit. Initial management should follow advanced trauma life support protocols to help identify and manage life-threatening injuries. Many prehospital retrieval protocols include the use of a pelvic binder with suspected pelvic fractures.⁶ The correct application of the pelvic binder should be confirmed, and skeletal traction should be considered where vertical instability is present. Pelvic fractures are seldom isolated injuries and therefore further management may be dictated by the various injuries sustained.

Diagnosing pelvic injury in the context of major trauma should be determined by mechanism of injury, clinical examination, and radiological evidence. The pelvis should not be mechanically stressed as this will risk destabilising clot formation. Log rolling should be avoided, and straight lifts are recommended in the initial period. The haemodynamic stability of the patient will determine which radiological examinations should be undertaken. If the patient responds to initial resuscitation, the patient should proceed for a CT scan. A contrast CT scan will help identify additional injuries and identify bleeding from pelvic vessels amenable to percutaneous intervention. Although previously discouraged in unstable patients, the ease at which they can now be carried out has led to improved outcomes.⁷

If the patient is unresponsive to resuscitation, rapid intervention is required if mortality is to be avoided. Decision making should be consultant led with input from all specialties involved in the patient's care. Bedside ultrasound may help rule out other causes of shock such as tension pneumothorax and pericardial tamponade, and an AP radiograph of the pelvis will help guide the diagnosis before transfer to theatre. The immediate options include angiography and embolisation, which can be carried out swiftly if the facility is readily available, or pelvic packing after an emergency laparotomy.

Analgesia

I.V. morphine should be used as the first-line analgesic and titrated to effect with the consideration of ketamine as a second-line agent if morphine fails to offer adequate pain relief. Intranasal diamorphine can be administered if i.v. access is yet to be established. NSAIDs should be avoided in the acute phase of management. The application of a pelvic binder and splinting of any associated limb fractures will also help reduce pain on movement.

Pelvic bleeding

Bleeding in pelvic fractures is most commonly from the presacral venous plexus, followed by exposed fracture surfaces, or rarely arterial injury. It can be catastrophic as the pelvic cavity and retroperitoneal space can accommodate an entire circulating volume before any tamponade effect.⁸ Differentiating between arterial or venous bleeding can be difficult without imaging, and management of these patients will be influenced by the services available locally. The likelihood of arterial injury is increased significantly in patients who are unresponsive to resuscitative measures.⁹ There is significant variation in practice across UK trusts because of differential access to interventional radiology and surgical training.¹⁰ The use of protocols has been shown to reduce mortality in this cohort of patients, and these should be individually designed in each trauma centre based on the expertise and facilities available.¹¹

The pelvic binder

The shift from external pelvic fixation to the early use of pelvic binders has made a major contribution to the care of patients presenting with severe pelvic fractures.¹² Various devices to help splint the pelvis are in use and range from a simple bed sheet to more complex devices. The function of the binder is to approximate the fracture ends to reduce haemorrhage, temporarily stabilise the pelvis, and reduce pain on movement. The binder should be placed over the greater trochanters, and correct application will allow access to the abdomen for laparotomy if required. Access to the groin may not always be possible for angioembolisation and temporary loosening or removal may be necessary.

Application of a pelvic binder is not without complications. Vertical displacement will not be reduced with a pelvic binder alone, and its use in lateral compression fractures may increase deformity.¹³ Pressure sores, nerve injuries, and tissue necrosis have also been reported and can be avoided by minimising the length of time the binder is applied.¹⁴

The effective use of a pelvic binder may conceal pelvic injuries on imaging, and cautious interpretation is required.¹⁵ Temporary removal of the pelvic binder for imaging or soon after achievement of haemodynamic stability is not recommended. Clotting mechanisms may no longer be intact and clot disruption may lead to irretrievable haemorrhage. The National Institute for Health and Care Excellence (NICE) suggest all pelvic binders should be removed within 24 h of application.⁶ In practice the binder should be reviewed before this to ensure it is removed at the earliest opportunity. This may be when going to the operating theatre for external fixation or when senior surgical review has deemed it safe, providing haemodynamic stability has been achieved and clotting parameters are in range.

Surgical options

Surgical stabilisation

Surgical fixation is divided into two stages: initial stabilisation followed by definitive fixation. Stabilisation techniques include application of an external fixator (Fig. 3), skeletal traction to realign the femoral head with the acetabulum, pelvic packing, or radiological embolisation. These are life- or limb-saving procedures and may be undertaken out of hours, soon after initial presentation.

Fig 3.

Pelvic X-ray after stabilisation using external fixation.

The application of an external fixator involves inserting percutaneous screws into the iliac crests (superior route for temporary external fixation) or the supra-acetabular region of the ilium (anterior route for definitive fixation). The fracture is manually reduced and connecting rods are used to maintain a stable construct.

In the presence of an associated bowel injury, the use of faecal diversion is well established. This involves performing a colostomy to minimise the risk of contamination of fracture sites with the stoma sited in the upper aspect of the abdomen. This may also be considered in open pelvic fractures to aid nursing care and help prevent wound contamination.

Surgical fixation

Definitive fixation (Fig. 4) aims to achieve and maintain reduction to stabilise the disrupted ring, aid early mobilisation, prevent deformity, and minimise long-term disability. Open methods of fixation remain the gold standard, but percutaneous methods are increasingly used as they reduce surgical time and soft tissue disruption, and avoid the complications associated with open surgery.¹⁶ Percutaneous techniques may be considered by experienced surgeons in polytrauma patients or those with significant soft tissue damage.

Fig 4.

Pelvic X-rays after surgical fixation of the pelvis using anterior plating and ileosacral screw insertion (left); and after anterior and posterior pelvic plating (right).

Approach to the anterior ring

A Pfannenstiel incision will allow reduction and plate fixation of the pubic diastasis and is the most commonly used approach. A vertical midline incision may be used where greater visualisation and surgical access is required. Sacroiliac dislocations can be managed with anterior sacroiliac plating or percutaneous iliosacral screws.

Approach to the posterior ring

A posterior midline incision allows for access to the posterior surface of the sacrum and both sacroiliac joints. A more lateral approach will give further access to the posterior ilium. For sacral fractures, a percutaneous approach in the supine position can be used with screw fixation through the ilium into the body of the sacrum with X-ray guidance. In the presence of compromised soft tissues, the possibility of wound breakdown after posterior plating must be kept in mind.

Approach to the acetabulum

The surgical approach to the acetabulum is dependent upon whether the fracture is of the anterior or posterior column. The ilioinguinal approach in the supine position is used for fractures of the anterior column, and the Kocher–Langenbeck approach can be used in the lateral or prone position for fractures of the posterior column. Associated injuries of the pelvic ring may alter the approach.

Anaesthetic considerations

Preoperative assessment

Communication with the multidisciplinary team is paramount in the management of patients with traumatic pelvic fractures. The planned surgical approach should be discussed as additional injuries can limit patient positioning and may need addressing concurrently. Urological injuries might contraindicate catheterisation and input from the urology team may be required. Intraoperative cell salvage should be organised and 4–6 units of red blood cells should be cross matched. Coagulopathy should be reversed and significant electrolyte abnormalities should be corrected. Patient consent includes a discussion of positioning related complications, blood transfusion, and a plan for postoperative analgesia. ‘Polytrauma’ patients with major injuries or those with significant haemorrhage from the pelvic fracture itself will require a critical care bed after surgery. Critical care should also be considered for patients with open pelvic fractures or elderly patients.

Intraoperative management

The conduct of intraoperative management will vary depending upon the urgency and nature of surgery. All patients should be monitored as per Association of Anaesthetists of Great Britain and Ireland (AAGBI) guidance. Two large-bore i.v. cannulae alongside an arterial line are mandatory because of the risk of significant blood loss. I.V. access may be limited by the presence of limb injuries, and an ultrasound-guided rapid infusion cannula or central venous catheter should be considered. Cervical collars can be removed to aid intubation, after which they should be reapplied. A reinforced tracheal tube is inserted for patients undergoing surgery in the prone position. The patient can lie supine, prone, or in the lateral decubitus position depending upon the surgical approach. Additional members of staff will be required to care for limb injuries if positioning the patient prone or if the patient requires log-rolling. Chest drains, suprapubic catheters, and extra-ventricular drains may also be present and need to be carefully handled. The presence of an external fixator device does not prohibit the use of the prone position. In slim patients, the Montreal mattress can be manipulated to accommodate the frame. Alternatively, a chest roll or multiple pillows can be used. Prophylactic antibiotics should be administered as per local trust guidelines. Tranexamic acid is administered in a loading dose of 1 g followed by a 1 g infusion. Active mechanical compression devices should be used during the procedure and continued in the post-anaesthesia care unit.

Postoperative management

Multimodal analgesia including the use of local anaesthetic wound infiltration will aid postoperative pain management. The use of NSAIDs in the immediate postoperative period after fracture surgery has been debated because of its potential to affect bone healing.¹⁷ In the absence of robust clinical evidence to support this, we routinely prescribe NSAIDs after pelvic fixation in stable patients. Owing to the risk of renal toxicity and platelet dysfunction, they should be avoided after major haemorrhage.

For acetabular surgery, continuous passive motion devices are commonly used after surgery and require well-functioning epidural anaesthesia. This may not be necessary if the patient is to remain sedated in the intensive care unit, and monitoring of neurological blockade is not possible. Positioning for epidural catheter insertion is limited by pain, and it is commonly sited after general anaesthesia in our institution, at the start or end of the procedure. The perceived benefits must outweigh the risks of performing epidural anaesthesia in an anaesthetised patient, and these should be considered carefully for each patient. The potential for significant blood loss and coagulation abnormalities will increase this risk and alter your approach.

Patients with multiple injuries or significant blood loss will require critical care after surgery. Those with isolated pelvic fractures with an uneventful intraoperative journey can be managed in a ward area.

Thromboprophylaxis

The best approach to thromboprophylaxis in patients with traumatic pelvic injuries is yet to be determined because of the disparity of the evidence currently available. The lack of consensus has resulted in significant variation in practice across the UK.¹⁸ The incidence of deep vein thrombosis (DVT) after pelvic trauma is between 35% and 60%, with 25–35% being proximal in nature.19, 20 A proximal thrombus is more likely to embolise, and the reported rates of fatal pulmonary embolism (PE) are 0.5–2%.¹⁹ Mechanical prophylaxis should be instituted soon after admission if it is not precluded by associated lower limb injuries. Chemical prophylaxis should be introduced once the patient is haemodynamically stable and clotting is confirmed to be within normal parameters. When delayed for more than 24-h, it has been shown to be associated with a significant increase in DVT and PE and should therefore be reviewed regularly within this period.²¹ Time to surgery has also been shown to be a risk factor, with a delay to surgery associated with an increase in thrombotic complications.²²

The current evidence base does not support the routine use of screening for DVT using ultrasound or the prophylactic insertion of a temporary inferior vena cava filter (IVCf).22, 23 The sensitivity of bedside ultrasound in detecting DVT and the practicality of performing it on a patient with multiple injuries limits its use. The insertion and removal of an IVCf is not without complication and the facility may not be easily available. Managing associated traumatic brain injuries is likely to delay thromboprophylaxis and surgery, and these patients will be at an increased risk of thrombotic events. Prophylactic insertion of an IVCf in this cohort of patients has been suggested.²² Until more robust evidence is available, early initiation of thromboprophylaxis and surgical intervention appears the best approach to preventing thromboembolism.

Pelvic fractures in children

Pelvic fractures in children are rare because of the greater elasticity of the pelvic joints and are therefore usually secondary to high impact injuries. The growing pelvis does not offer the same protection as the adult pelvis to intrapelvic viscera, which may still be injured in the absence of a pelvic fracture. The extent of the associated injuries from the initial trauma tends to lead to a greater morbidity and mortality than the pelvic fracture itself.

Conclusion

Traumatic pelvic fractures are associated with a high mortality, and good communication between the multidisciplinary team is essential to ensure best chance of survival. Initial management is tailored to patient resuscitation and arresting haemorrhage utilising the modalities locally available, followed by early definitive fixation. The evolution of trauma systems and technological advances in imaging, embolisation techniques, and minimally invasive surgery has improved this process. Lasting repercussions of pelvic trauma include chronic pain and impaired physical and mental health, and improving the quality of life of survivors remains a challenge.

Declaration of interest

None declared.

MCQs

The associated MCQs (to support CME/CPD activity) will be accessible at www.bjaed.org/cme/home by subscribers to BJA Education.

Acknowledgements

The authors thank Mr Nikhil Shah, consultant orthopaedic and trauma surgeon, for advice offered during the preparation of this manuscript.

Biographies

Mohammed Akuji FRCA is a specialty registrar at Salford Royal NHS Foundation Trust.

Eleanor Chapman BSc FRCA is a consultant anaesthetist at Salford Royal NHS Foundation Trust.

Paul Clements FRCA is a consultant at Wrightington, Wigan, & Leigh NHS Foundation Trust. He has interests in education and both urgent and elective orthopaedic surgery.

Matrix codes: 1B04, 2A02, 3A08