Neobook — clinical reference

PEARL
Dupuytren Fracture
Maisonneuve Fracture
Pilon Fractures
Proxumal fifth metatarsal shaft fracture (Jones fracture)

Description

The most commonly used fracture classification schemes are based on either mechanism of injury or anatomic location of the fracture.

The Lauge-Hansen (LH) classification utilises mechanism of injury and classifies ankle injuries based on the position of the foot with respect to the ankle (supination or pronation) and the motion of the talus within the mortise (adduction, abduction, or external rotation) at the moment of injury.

One can immediately appreciate that if the history is unreliable or patient states “I don’t know I twisted it” it can become difficult to ascertain the mechanism.

Danis-Weber (DW) classification scheme groups injuries according to anatomic location of the fibular fracture.

This system is useful, since the level of the fibular fracture determines the integrity of the syndesmosis and thus the need for operative repair.

Weber type A injuries include fractures of the lateral malleolus below (distal to) the mortise and are managed non-operatively.
Weber type B injuries feature fibular fractures at the level of the mortise and are stable only if the fibular fracture occurs in isolation; medial joint involvement creates an unstable situation that requires operative correction in the majority of cases.
Weber type C injuries include fibular fractures above(proximal to) the mortise. Because these injuries disrupt the syndesmosis distal to the fracture, they require open reduction and internal fixation (ORIF)

PEARL

From a practical point of view in the emergency centres we use the Weber classification to access the urgency for orthopaedic referral and the Lauge-Hansen (mechanism of injury) to scrutinise the plain films for fractures.

Weber type A injury – posterior splint (back slab) non weight bearing to return to next available fracture clinic for circular cast and review by orthopaedics in 4-6 weeks.
Weber type B injury – posterior splint with sugar-tong (stirrup) splint to increase the stability of the joint, non-weight bearing and consider referral to district level with availability to orthopaedic follow up at the next fracture clinic.
Weber type C injury – splint in the emergency centre as for Weber B (reduction as needed) with referral to inpatient orthopaedic team.

Other ankle fractures

Dupuytren Fracture

This is a fibular shaft fracture located 4-10 cm above the mortise that occurs during a combination of forceful eversion and external rotation. Since the syndesmosis ruptures distal to the fracture, the mortise is destabilised. Patients are unable to bear weight and exhibit tenderness of the supramalleolar fibula. Beware that the fibular fracture may lie above the visible edge of the ankle film. One radiographic clue is a widened medial clear space (talar shift) on the AP ankle view.

If a Dupuytren fracture is suspected based on history, physical examination, or routine ankle series, order dedicated leg films.

Maisonneuve Fracture

This spiral fracture of the proximal fibula is similar to the Dupuytren fracture in that it occurs during external rotation of the talus and disrupts the syndesmosis. These highly unstable injuries are often associated with fractures of the medial malleolus or disruption of the deltoid ligament. Tenderness of the proximal fibula is the most important clinical clue to this diagnosis. Ankle films may show a widened medial clear space and decreased tibiofibular overlap, but they will miss the proximal fibular fracture (for which leg or knee films are required).

Pilon Fractures

These dramatic appearing, intra-articular fractures of the distal tibial diaphysis typically result from axial loading forces, such as a fall or jump from a significant height or a head-on motor vehicle collision.

Forced dorsiflexion at the ankle joint drives the talus into the tibia and usually creates a comminuted fracture of the plafond, with loss of mortise integrity.

Proximal Fifth Metatarsal Shaft Fracture

(Jones Fracture)

It results from a direct blow or repetitive stress to the lateral aspect of the

foot. This injury typically involves a transverse fracture of the proximal metatarsal shaft and must be distinguished from the less significant avulsion fracture of the tuberosity (pseudo-Jones fracture). The pseudo-Jones fracture occurs at, or proximal to the distal aspect of the cuboid, whereas the Jones fracture is usually even with or slightly distal to, the distal cuboid.

Fractures of the proximal metatarsal shaft commonly present with pain at the lateral aspect of the ankle or foot and may be difficult to diagnose if the emergency physician fails to palpate the fifth metatarsal carefully in all patients who complain of ankle injury. If the base of the fifth metatarsal is tender, order foot films.