Lauge-Hansen classification of ankle fracture

1.Ashhurst classification: According to the nature of external force, it can be divided into four types: adduction, abduction, external rotation and vertical compression.

2.AO classification: also known as Danis-Weber classification, according to the height of fibular fracture, the relationship between lower tibiofibular syndesmosis and tibiofibular distance.

3.Lauge-Hansen classification: classification according to damage mechanism.

Supination: plantar flexion varus, medial margin raised, lateral margin lowered.

Internal rotation: the dorsum of the foot is abduction and eversion, and the lateral edge is raised and the medial edge is lowered.

During adduction, the upper joint of talus faces outward and the lower joint faces inward.

Abduction means that the upper joint of talus is turned inward and the lower joint is turned outward.

The adduction and abduction movements are the rotation of talus in ankle joint along its own longitudinal axis.

The movement of internal and external rotation talus relative to tibia is the movement of talus in the horizontal plane. It's called internal rotation from bone and external rotation from bone.

The first half of each classification refers to the position of the foot when injured, and the second half refers to the direction of external force. This paper expounds the whole process of ankle fracture and dislocation and the degree of injury, and expresses the relationship between ligament injury and fracture. More than 95% of X-rays can be classified according to this.

Supination first damages the last medial side of the lateral structure, while pronation first damages the last lateral side of the medial structure.

Injury mechanism: when the foot is injured, the talus varus, and the lateral ankle joint is pulled first, which leads to the injury of the lateral ankle joint or lateral ligament. When the external force continues to act, the medial ankle joint is squeezed, resulting in an approximately vertical medial ankle joint fracture.

I degree: lateral ankle avulsion fracture or lateral ankle ligament rupture. The broken line of lateral malleolus is lower than the plane of tibiotalus joint, and most of them are transverse fractures or avulsion fractures at the top of lateral malleolus. When ligament is injured, varus stress radiograph can show talus tilt and front drawer test is positive.

Grade II: Grade I plus medial malleolus fracture. The fracture line is located at the junction of the medial ankle joint and the horizontal ankle joint, that is, the inner upper corner of the ankle point. The fracture line inclines inward and upward, or vertically upward, which is often accompanied by bone compression or cartilage surface injury below the upper horn joint at the ankle point.

Injury mechanism: when the foot is injured, it is in varus position (supination position), and the talus is subjected to external rotation force, or the talus inside the calf is subjected to relative external rotation force. Talus rotates outward and backward around the medial axis of ankle point, and impacts the lateral ankle and shifts backward. Causing anterior talofibular ligament injury-fibular fracture-posterior talofibular ligament or posterior ankle injury-medial ankle fracture. It is the most common type, accounting for more than half of joint fractures and dislocations.

Grade I: Fracture of tibiofibular anterior ligament or avulsion fracture of tibial anterior tubercle (Tillaux fracture or Chaput fracture).

Grade II: Grade I oblique coronal fracture, with lateral malleolus at the level of lower tibiofibular syndesmosis. The fracture line inclines from front to back, the side is more obvious, and some positions are slightly higher. The distal end of the fracture is still connected to the talus through the lateral ligament.

Ⅲ degree: Ⅱ degree plus posterior malleolus fracture. If the lower tibiofibula remains intact, the posterior ankle is mostly avulsion fracture, and the fracture block is small. However, if combined with the external force of talus, the posterior ankle is larger and the lateral ankle is higher. Separation of the lower tibiofibula may occur.

ⅳ degree: ⅲ degree plus medial malleolus fracture or triangular ligament rupture. Due to the traction of the triangular ligament and the impact of the posterior medial part of the rotating talus, the medial structure was damaged. Separation of lower tibiofibula. When the medial malleolus is small and the talus is obviously displaced outward, we should think of the deep rupture of the triangular ligament.

Injury mechanism: When the foot is in pronation position, the talus is subjected to strong abduction force at ankle point, which leads to avulsion fracture of medial malleolus or ligament rupture-incomplete or total injury of lower tibiofibular ligament-fibular fracture.

I degree: fracture of medial malleolus or rupture of triangular ligament. Most fractures are lateral avulsion fractures below the ankle joint space.

ⅱ degree: ⅰ degree with injury of lower tibiofibular ligament. It can simply damage the anterior or posterior ligament of the lower tibiofibular joint, resulting in incomplete injury of the lower tibiofibular joint; Or the lower tibiofibular ligament is completely broken and the lower tibiofibular ligament is separated.

Ⅲ degree: Ⅱ degree with fibula fracture. Fibula fracture is short oblique or butterfly-shaped, and butterfly-shaped bone fragments are often located outside the fibula. Lateral manifestations are transverse fractures. Whether the lower tibiofibular ligament is separated depends on the injury of the lower tibiofibular ligament and the height of fibular fracture.

Injury mechanism: the foot is in pronation position at the time of injury. When the talus is subjected to external rotation force, the talus rotates and shifts anterolateral with the transverse axis. Causing medial malleolus avulsion fracture or triangular ligament fracture-tibiofibular anterior ligament injury-fibular fracture-tibiofibular posterior ligament injury or posterior ankle fracture.

I degree: fracture of medial malleolus or rupture of triangular ligament. The broken line of the medial malleolus is oblique, and it is oblique from front to back on the sagittal plane, especially on the lateral radiograph of the ankle joint.

ⅱ degree: ⅰ degree with anterior ligament injury of tibia and fibula. If the tibiofibular anterior ligament is intact, it can also cause fracture of tibiofibular anterior ligament at the attachment of tibial tubercle.

Ⅲ degree: Ⅱ degree with lateral malleolus fracture. The lateral malleolus fracture is located near the lower tibiofibular syndesmosis, spiral, with the fracture line from front to back and inclined forward, and the fracture position is high. Separation of lower tibiofibula.

Ⅳ degree: Ⅳ degree with posterior tibiofibular ligament injury or avulsion fracture of ankle joint. The bone mass of the posterior malleolus is larger than that of the bearing articular surface of the lower tibia 1/4. Separation of lower tibiofibula.

Simple vertical compressive external force. According to the position of ankle joint and foot injury, it can be divided into dorsal extension type, plantar flexion type and vertical type (Plion fracture)

Vertical compressive fracture caused by comprehensive external force. It can be divided into vertical external rotation type, vertical adduction type and vertical abduction type.

It is more common in supination-supination fracture, large posterior ankle, long oblique fracture of fibula coronal plane and high fracture position.

1. Classification according to injury mechanism is of guiding significance for manual reduction and fixation.

2. Inferring from the injury mechanism, we can find the invisible injury-ligament injury.

3. It has certain guiding significance for finding the causes of poor postoperative reduction.

Lateral malleolus: it is the key to judge the classification. 1. Different fracture modes; 2. The fracture position is different.

Lateral malleolus: it is the key to judge the classification. 1. Incomplete fracture; 2. The fracture position is different.

Posterior ankle: avulsion fracture of posterior ankle can exist except supination-adduction type, because the avulsion fracture block is generally small. When the fracture of the posterior ankle is large, it is generally considered to be caused by vertical external force of the ankle joint.

Maisonneuve fracture: pronation and supination degree III, proximal fibula fracture.

Cotton fracture: trimalleolar fracture

Bosworth fracture: ankle fracture and dislocation

Workman bone fragment: fracture of the back of ankle.

Dupuytren fracture: ankle fracture with separation of lower tibiofibula.

Le Fort-Wagstaffe fracture: The avulsion fracture of the anterior tibiofibular ligament or the anterior talofibular ligament at the attachment point of the fibula is a longitudinal fracture of the anterior edge of the lateral ankle.

Porter fracture: Ankle fracture with varus deformity.

Chaput fracture (or Tirau fracture)