MECHANISM AND PATHOANATOMY OF THE INTRAARTICULAR CALCANEAL FRACTURE

The mechanism and pathoanatomy of the acute intraarticular calcaneal f racture is produced by axial loading. A combination of shear and compr ession forces produce two characteristic primary fracture lines. Shear ing forces produce a fracture dividing the calcaneus into medial and l ateral portions. This fracture line typically splits the posterior fac et and can extend anteriorly to involve the anterior and cuboid facets . Compression forces divide the calcaneus into anterior and posterior portions. This fracture line can extend medially to involve the middle facet. Loss of calcaneal height and length are readily explained by t his mechanism.