Iliac wing fractures

Introduction

Isolated fractures of the iliac wing that do not involve the weight bearing axis of the pelvis, also known as Duverney fractures, are mechanically stable fractures because the pelvic ring remains intact.  They typically respond well to non-operative treatment, although the patient may hemorrhage from the internal iliac arterial system. These fractures are typically caused by vertically directed forces.

Posterior iliac wing fractures that involve the weight bearing axis are unstable and may be extra-articular or involve the sacroiliac (SI) joint to some degree.  Intra-articular fractures in which the posterior superior iliac spine remains firmly attached to the sacrum through the intact posterior ligamentous complex, also known as crescent fractures, are associated with impaction fractures of the ipsilateral anterior sacrum because of the lateral compression mechanism of injury.  In these fractures stable internal fixation can be achieved with extra-articular fixation.  On the other hand, fracture-dislocation are located more posteriorly in the SI joint and have little or no residual attachment of the posterior superior iliac to the sacrum.  These fracture-dislocations require trans-articular internal fixation. 

Classification

There is no formal classification scheme that specifically addresses iliac wing fractures.  However, they can be broken down into the following types:

Extra-articular

• Stable

• Unstable  

Intra-articular

• Stable
• Unstable

Presentation

Patients typically present with pain and varying amounts of deformity.  Patients may walk into the emergency room or may be unconscious depending on the mechanism and associated injuries.  Hypotension and shock can arise secondary to hemorrhage from the internal iliac arterial system.  Fractures of the iliac wing can also perforate the bowel and result in sepsis. 

Diagnosis

Any fracture of the pelvis caused by significant trauma should raise suspicion of trauma elsewhere (head, thorax, spine, etc.).  A thorough trauma physical exam is essential with special attention given to the manual pelvic stability test, rectal and vaginal exams, and distal neurovascular exam. 
Ideally, all patients should obtain a head, chest, abdominal, and pelvic CT.  Plain radiographs of the pelvis should include AP, inlet, outlet, and Judet views to assess for disruption of the pelvic ring and fractures of the acetabulum.  Pelvic CT sagittal and coronal reconstructions are often helpful to fully appreciate the pelvic fracture pattern. 

Treatment

Operative indications:

• Open fracture
• Fracture resulting in significant vascular or organ injury
• Iliac wing fracture creating pelvic instability (rare)
• Unacceptable deformity
• Avulsion fractures of the ASIS or AIIS in athletes or young patients (relative indication)

Isolated, stable, extra-articular fractures of the iliac wing are typically managed without surgery.  These fractures are painful; patients are mobilized with crutches or a walker until the pain decreases.  
Unstable, extra-articular fractures are rare and typically treated with open reduction, internal fixation (ORIF) through an anterior (iliac fossa) approach. Crescent fractures are commonly treated with ORIF.  Because stable fixation can be achieved with extra-articular fixation, they can be treated through an anterior or posterior approach.  Iliac wing fractures that involve SI fracture-dislocations should be fixed with transarticular internal fixation.     

Complications

Complications include infection, neurovascular injury, bowel injury, malunion / deformity.

Outcomes

Outcomes are dependent on the severity and presence of concomitant injuries.  The iliac wing is surrounding by muscle and typically heals quickly.