Pelvic fractures

What is a pelvic fracture?

Pelvic fractures range in severity from low-energy, relatively benign injuries to life-threatening, unstable fractures.

The ring formed by the fused bones of the ischium, ilium and pubis attaches to the sacrum and contains vital structures including major blood vessels and nerves and digestive and reproductive organs. Major pelvic fractures can therefore be catastrophic, mainly due to blood loss. They result from very high-energy trauma such as those generated in road traffic accidents, crush injuries or falls from height. They require urgent hospital treatment.

Less severe, stable fractures which do not damage the structural integrity of the pelvic ring can result from lower-energy impact. They typically involve fractures of only one of the pelvic bones. Pubic rami fractures with insignificant or minimal trauma can be a presentation of osteoporosis.

Avulsion fractures are generated by sudden muscle contractions. These do not affect the integrity of the pelvis, can be managed conservatively and often go undetected.

Pelvic fractures represent 5% of all traumatic fractures and 30% are isolated pelvic fractures. Pelvic fractures are found in 10-20% of severe trauma patients and their presence is highly correlated to increasing trauma severity scores.¹

• The most significant fractures result from major trauma.

• Isolated pubic ramus fractures are common and often missed.

• Pelvic fractures in children are rare and often the result of high-energy trauma.²

• Avulsion fractures can result from sporting activities. They are particularly common in sporty teenagers and typically involve the hamstrings and the ischium, resulting from a sudden muscle contraction. They can go undetected.

• Osteoporotic pelvic fractures, often following one or more relatively trivial traumatic incident, are relatively common among persons over age 60.³ Routine screening for osteoporosis in older people with a pelvic fracture could improve rates of osteoporosis diagnosis.⁴

Any history of significant trauma should raise consideration of a pelvic fracture. Pelvic fracture symptoms may include:

• Tenderness, bruising, swelling and crepitus of pubis, iliac bones, hips and sacrum.

• Haematuria

• Rectal bleeding.

• Haematoma or palpable fracture line on rectal examination.

• Haematoma above the inguinal ligament, the proximal thigh or the perineum.

• Loin bruising due to retroperitoneal bleeding.

• Neurological and vascular abnormalities in either or both legs.

• Instability on hip adduction and pain on hip motion suggests an additional fracture of the acetabulum.

• In men: signs of urethral injury, including a high-riding or boggy prostate on rectal examination, scrotal haematoma or blood at the urethral meatus.

• In women: vaginal bleeding and/or a palpable fracture line on bimanual vaginal examination.

High-impact, unstable pelvic fractures

• Major pelvic fractures present rapidly due to the circumstances of the trauma and the patient's clinical condition.

• Patients present with pain and shock. As pelvic fractures may be closed the degree of blood loss may not be initially clear.

• Pelvic instability is likely. Deformity may not be initially obvious.

• If attending road traffic accidents the ability of patients with unstable pelvic fractures, initially, to move around and attempt to walk after the injury is well known and should not mislead the clinician into thinking the pelvis is intact.

Low-impact, stable pelvic fractures

• In these fractures the effect on function can be considerably less obvious.

• Blood loss is less likely to be haemodynamically challenging.

• Pain on walking is usual but patients often walk unaided.

• Attempts to 'spring the pelvis' to assess stability should be avoided as this is unreliable and may cause additional bleeding or injury.

Different classification systems exist. Some are based on the mechanism of injury, some on anatomic patterns and some on the resulting instability requiring operative fixation . Those most commonly referenced are the Tile Classification and the Young-Burgess Classification. One review found the Young-Burgess system less prone to intra-observer variability. More information about these systems can be found in the further reading section of this leaflet. Tile classification

Investigations

A stable pelvic fracture may be found in primary care when doing a pelvic x-ray for another reason (eg, to look for hip osteoarthritis), but the acute investigation and management is a matter for secondary care. It may include the following:

• Urinalysis: may show gross or microscopic haematuria.

• Pregnancy test in a female of childbearing age.

• Serial haemoglobin and haematocrit measurements to monitor ongoing blood loss; group and cross-match.

• Imaging (x-ray, CT, ultrasound for intrapelvic bleeding or fluid).

• Interventional radiological procedures such as retrograde urethrography to detect urethral damage, arteriography to look for intraperitoneal bleeding and cystography to look for bladder damage.

The optimal treatment strategy should keep into consideration the haemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. Management is done in secondary care and may include the following:

• Initial resuscitation if needed, following Advanced Trauma Life Support protocols.

• Surgery for some patients, bed rest, and then mobilisation with walking aids for those with less severe and more stable fractures.

• Anticoagulation to reduce thrombosis risk whilst immobile.

• Appropriate management of fluid balance and any co-morbidities while the patient is in hospital.

• A multidisciplinary approach, including physiotherapy, to ensure mobilisation when possible.

• Increased incidence of thrombophlebitis.

• Intrapelvic compartment syndrome.

• Continued bleeding from fracture or injury to pelvic blood vessels.

• Associated bladder, urethral prostate or vaginal damage is common.

• Associated thoracic and abdominal injuries occur in 10-20%; massive internal haemorrhage may occur.

• Sexual dysfunction may be a long-term problem.

• Prognosis varies depending on severity of fracture and associated injuries.

• The high mortality of severe pelvic trauma, up to 40% in some studies, is related to actively bleeding pelvic injuries and/or associated injuries to the head, abdomen or chest. ⁷¹⁸

• Stable pelvic fractures heal very well.

• Patients who also have acetabular fractures do significantly worse than those without this added complication.

• Prolonged physiotherapy and rehabilitation will be needed for a return to full fitness.

• Subsequent problems may involve long-term effects on internal pelvic structures which may leave patients with symptoms such as persistent pain, impaired mobility or sexual dysfunction.

• Regardless of the type of fracture, neurological injury is a predictor of poor outcomes. ⁹¹⁰

• Car safety - seat belts, speed restrictions, impact protection systems.

• Any safety procedure that reduces risk of falls from high levels, including site safety on construction sites.

• Increase diagnosis and effective management of osteoporosis.

• Active approach to the management of impaired mobility in the elderly, with physiotherapy and occupational therapy programmes to address home safety, core stability, balance, fitness, strength and aids to walking.

Dr Mary Lowth is an author or the original author of this leaflet.