The plantar ecchymosis sign in fractures of the calcaneus.

The appearance of a central plantar ecchymosis is not an uncommon occurrence 24-48 hours after a compression fracture of the calcaneus. In order to understand the development of this characteristic ecchymosis, the authors studied the anatomy of the fascial compartments in five adult cadaveric feet. The anatomic basis for the plantar ecchymosis sign is demonstrated through dissection of the three osteofascial compartments within the sole of the foot. Dye injected into the central compartment overlying the calcaneal tuberosity reproduces the observed clinical sign. The specificity of this sign for compression fractures of the calcaneus makes it a useful clinical observation in cases where the diagnosis of fracture is uncertain.