Today I’d like to share one of these little gems with you. This one pertains to the topic of ankle fractures. We are all taught in school the Lauge-Hansen classification of ankle fractures with four primary fracture patterns that occur based on the position of the foot at the time of the injury and the direction of rotation of the leg. This system is supposed to be highly useful in that it predicts the associated soft tissue injuries that we cannot see on radiographs and helps with predicting prognosis. It’s also supposed to help us determine the method of closed reduction of the fracture before fixing it surgically.

Lauge-Hansen Steps Up to the Plate

Just for fun, review the figure above demonstrating a common ankle fracture. You’ll note a spiral oblique fracture of the fibula that begins at the level of the ankle joint and a second transverse fracture of the medial malleolus. In the Lauge-Hansen world, this would be classified as a Supination External Rotation (SER) type 4 fracture, and one would assume damage to certain anterior and posterior ankle ligaments despite not being able to see them on the radiographs. For you detail-oriented people, let’s assume the posterior malleolus isn’t fractured. From this radiograph, you can also determine the mechanism of injury and how to reduce the fracture before repairing it surgically. But here comes the rub…you’d be wrong.

You’d be wrong because the Lauge-Hansen classification system is, for the most part, wrong. Yes, my friends, what you’ve been taught is incorrect!

And Another One Bites the Dust

Here’s the story. As you probably already know, Lauge-Hansen determined his classification system by using freshly amputated (above the knee) limbs rather than live humans. He fixed the feet to a vise, hand-fractured the ankles, took radiographs and dissected the ankles to determine the extent and type of damage.¹ Based on these results, we have been using the classification for the last 66 years. For those of you who are who are not lunatics, you’ll understand that obviously he couldn’t do this study in vivo on actual people, so it’s the best we had.

Batter Up!

In 1997 Michelson, et al. performed a similar experiment with 30 cadaveric ankles and found they were unable to reproduce the Supination External Rotation pattern. They determined that the Lauge-Hansen classification did not correspond to the predicted pattern.²

Strike One!

More recently, in 2015 Kwon and colleagues (hailing from Beth Israel Deaconess Hospital and Harvard University) published our second of three gems. These researchers, in the best spirit of the scientific method, repeated Lauge-Hansen’s original study as closely as possible, focusing on the Supination External Rotation pattern. They took 10 fresh frozen cadavers amputated above the knee, fixed the foot to a board, and the femur was stabilized in a vice. They then repeated the fracture experiment as described by Lauge-Hansen.³ Sadly, no specimen demonstrated the pattern of injury predicted previously for either bone or soft tissue.

Strike Two!

It’s looking pretty bad for team Lauge-Hansen with two strikes and no one on base. Here comes our last pitch: a study in 2009 by Haraguchi and Armiger at Johns Hopkins University. These researchers subjected 23 cadaver ankles to a loading mechanism that reproduced the Lauge-Hansen Pronation External Rotation pattern. As a quick reminder, this is the fracture that is found on the fibular shaft that occurs above the level of the ankle joint (commonly with a fractured medial ankle as well). Instead of the ankle fracture pattern previously predicted, they found a different set of patterns that depended on how the forces were applied to the ankle. In fact, in 8 of 15 specimens, the fibula fractured before the medial malleolus, an impossibility according to the Lauge-Hansen system.⁴

Strike Three; You’re Outta Here!

For those of you who have relied on this system, your head might be spinning. You may also be yelling, “Why did they teach me this stuff if it’s wrong?” Take a deep breath and let me quickly show you the silver lining. Haraguchi and Armiger actually simplified this entire issue by demonstrating that the fractures occur based entirely on what type of rotation was occurring at the time of the injury, and that most of these injuries occur in a pronated foot. A low oblique fracture (the exact one predicted by the Supination External Rotation mechanism), like the one in the radiograph above, occurs when there is primarily an external rotation moment (twisting of the foot away from the center of the body), while a higher fibular fracture occurs when there is primarily an abduction moment (with the leg swinging outward with a hinge at the point of the fracture).⁴

Instead of four different fracture patterns and foot positions we now have two. Here’s what we know now from these three studies:

The Lauge-Hansen system served us well in its time, but that time has passed. It’s time to send L-H to the locker room. In this case, our little gems have had big effects on our understanding of ankle fractures, and I highly suggest reading Reference 4 below for a full understanding. I hope you find a little gem in your practice and share it with the rest of us.

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