What are the types of pelvic fractures?

Types of Pelvic Fractures

Pelvic fractures are classified into four main injury patterns based on the direction of force and resulting instability: lateral compression (LC), anteroposterior compression (APC), vertical shear (VS), and combined mechanism (CM), with the Young and Burgess and Tile classifications being the most widely used systems. 1

Primary Classification Systems

Young and Burgess Classification

This system categorizes pelvic ring injuries based on the mechanism of injury and is particularly beneficial for specialists 1:

• Lateral Compression (LC): Injuries caused by lateral forces, subdivided into LC I, II, and III based on severity 1
• Anteroposterior Compression (APC): External rotation injuries including "open book" fractures, graded as APC I, II, or III 1
• Vertical Shear (VS): Complete disruption with vertical displacement 1
• Combined Mechanism (CM): Combination of injury patterns 1

Tile Classification

An alternative system that is more easily remembered and applied in clinical practice, also based on force direction and pelvic instability 1

Type A, B, C Classification

A broader categorization based on stability 2:

• Type A: Stable pelvic ring fractures (70-80% of all pelvic injuries) 2
• Type B: Partially stable lesions with rotational instability, including "open-book" and "bucket-handle" fractures 2
• Type C: Completely unstable with full disruption of the posterior sacroiliac complex, typically from high-energy trauma 2

WSES Clinical Classification

The World Society of Emergency Surgery (WSES) provides a clinically-oriented classification that prioritizes hemodynamic status over mechanical stability, which is critical for immediate management decisions 1:

Minor Injuries

• WSES Grade I: Hemodynamically stable AND mechanically stable lesions 1

Moderate Injuries

• WSES Grade II: APC II-III and LC II-III patterns that are hemodynamically stable but mechanically unstable 1
• WSES Grade III: VS and CM patterns that are hemodynamically stable 1

Severe Injuries

• WSES Grade IV: Any hemodynamically unstable pelvic ring injury, regardless of mechanical status 1

Fragility Fractures of the Pelvic Ring (FFP)

A specialized classification for low-energy fractures in elderly patients 3:

• FFP Type I: Stable fractures suitable for conservative treatment 3
• FFP Type II: Partially stable fractures requiring percutaneous fixation after failed conservative trial 3
• FFP Type III: Unstable fractures requiring open reduction and internal fixation 3
• FFP Type IV: Bilateral unstable fractures requiring bilateral fixation 3

Key Clinical Distinctions

Posterior vs. Anterior Stability

The posterior sacroiliac complex is more critical to pelvic ring stability than anterior structures, despite the symphysis pubis and pubic rami contributing 40% of pelvic stiffness 2. This is why classification systems prioritize posterior lesion stability 2.

Open vs. Closed Fractures

Open pelvic fractures involving the perineum or bowel injury represent a distinct category requiring fecal diversion by colostomy 4.

Common Pitfalls

• Avoid classifying based solely on radiographic appearance without considering hemodynamic status, as WSES Grade IV (any unstable patient) takes precedence over mechanical classification for immediate management 1
• Do not underestimate Type B fractures as "partially stable"—they still require careful assessment and often surgical intervention 2
• The posterior sacroiliac complex disruption is the key determinant of true instability, not just anterior ring injuries 2