Calcaneal Fracture
The calcaneus is the largest tarsal bone and forms the posterior subtalar articulation.
Calcaneal fractures are divided into:
Extraarticular fractures
Intra articular fractures involving the posterior subtalar facet
Most major intra articular fractures result from axial loading, commonly after a fall from height.
The force drives the talus downward into the calcaneus, producing:
Posterior facet depression
Heel shortening
Heel widening
Varus deformity
Lateral wall blowout
Subfibular impingement
Associated lumbar spine fractures must be considered after axial load injuries.
Essex Lopresti classification
Based on the secondary fracture line.
Tongue type
The secondary fracture line exits posteriorly, producing a large posterior tuberosity fragment attached to the Achilles tendon.
The Achilles can pull the fragment superiorly, threatening the posterior heel skin.
Joint depression type
The secondary fracture line exits superiorly behind the posterior facet, leaving a separate depressed articular fragment.
These patterns require different reduction strategies.
Sanders CT classification
Based on the number and location of fracture lines through the posterior facet on coronal CT.
Type I
Nondisplaced or minimally displaced fracture, generally less than approximately 2 mm displacement, regardless of the number of fracture lines.
Type II
One primary fracture line divides the posterior facet into two articular fragments.
Subgroups A, B and C reflect the position of the fracture line from lateral to medial.
Type III
Two fracture lines divide the posterior facet into three articular fragments.
Subgroups AB, AC and BC reflect fracture line location.
A central depressed fragment is frequently present.
Type IV
Three or more fracture lines produce four or more articular fragments.
These are severely comminuted injuries with poor reconstructive prognosis and high risk of post traumatic subtalar arthritis. Increasing Sanders grade correlates with increasing reconstructive difficulty.
