Lauge-Hansen classification describes ankle fractures based on which mechanism?

Lauge-Hansen classification describes ankle fractures based on which mechanism?

• A. Time of injury
• B. Mechanism of injury (e.g., supination–external rotation, pronation–external rotation)
• C. Pain level
• D. Soft tissue status

Answer: (B)

This classification is about how the injury happened—the mechanism of injury, meaning the foot position (supination or pronation) and the direction of the applied force (external rotation, adduction, or abduction). The pattern of bone and ligament injuries follows that force sequence, so knowing the mechanism explains why a fracture pattern presents with certain accompanying ligament disruptions. For example, a supination–external rotation mechanism starts with specific lateral structures failing and progresses in a predictable order, while a pronation–external rotation mechanism involves different initial injuries and a different sequence. Because of this, Lauge-Hansen groups ankle fractures by mechanism rather than by time of injury, pain level, or soft tissue status.

This classification is about how the injury happened—the mechanism of injury, meaning the foot position (supination or pronation) and the direction of the applied force (external rotation, adduction, or abduction). The pattern of bone and ligament injuries follows that force sequence, so knowing the mechanism explains why a fracture pattern presents with certain accompanying ligament disruptions. For example, a supination–external rotation mechanism starts with specific lateral structures failing and progresses in a predictable order, while a pronation–external rotation mechanism involves different initial injuries and a different sequence. Because of this, Lauge-Hansen groups ankle fractures by mechanism rather than by time of injury, pain level, or soft tissue status.