Calcaneum Fractures

Mechanism of Injury

These fractures usually occur as a result of a fall from a height e.g. from a ladder and landing on one or both heels. The calcaneum is driven upwards against the talus and is either split or crushed.

Classification

Can be classified as:

• Extra-articular fractures
• 20 / 25% of calcaneal fractures
• Shearing or avulsion may occur of the: anterior process, the sustentaculum tali, the tuberosity, medial process or of the body.
• Intra-articular (fractures that split the talocalcaneal articular facet)
• 70 / 75% of calcaneal fractures
• More complex then extra-articular fractures as may result in an infinite variety of fracture patterns with varying degrees of displacement
• Two main fracture lines may occur: Primary fracture line running from the plantar aspect obliquely upwards into the posterior facet, which divides the calcaneum into anteromedial and posterolateral fragments; secondary fracture line which begins at the crucial angle (of Gissane) and extends posteriorly
• Essex-Lopresti’s classification (1952) of intra-articular fractures is commonly used
• Tongue type: where the secondary fracture line extends directly posteriorly producing a large superior, posterior and lateral fragment with the rest of the body forming the inferior fragment
• Joint depression type: this fracture occurs more frequently. The secondary fracture begins at the crucial angle, extends posteriorly, but deviates dorsally to exit the bone just posterior to the posterior articular facet. This fragment contains the majority of the posterior facet

Clinical Features

The patient usually presents following a fall. The affected foot is painful, tender and swollen. Involvement of the subtalar joint leads to a restriction in movement and the inability to walk. The heel may become broader and squatter as a result of lateral displacement; proximal displacement results in weakness of the calf muscles.

X-rays are needed to confirm the diagnosis: lateral, oblique and axial views. With regards to intra-articular fractures, any displacement of the fragments will show flattening of Bohler’s angle (normal 20º - 40º). CT scans are the investigation of choice for intra-articular fractures, with coronal and axial views being needed.