Anterior calcaneal process fracture = bifurcate ligament avulsion

Anterior calcaneal process  is in the anterolateral aspect, bordered by the navicular, cuboid and sinus tarsi at the anterior facet and the calcaneocuboid joint. 

Proximal attachment of the bifurcate ligament attaches to here and avulsion leads to anterior calcaneal process fracture. 

Best seen on the lateral view of the ankle or the lateral view of the calcaneus. 

Look at the the lateral aspect of the calcaneus on the AP view of the ankle.

Look out on the oblique view of the foot. 

Distal anterolateral cortex fracture = calcaneocuboid ligament avulsion

Presents as pain in the lateral aspect of the foot after inversion or plantar flexion injury. 

Most avulsion fractures occur at the attachments of the dorsal calcaneocuboid ligament.

Best seen on the AP and oblique views of the foot in the lateral aspect of the cuboid bone. 

Dorsolateral anterior calcaneus fracture = extensor digitorum brevis muscle avulsion

Inversion injury. 

Best seen on the AP view of the ankle along the lateral aspect of the calcaneus.

Look out on the the AP view of the foot in the anterolateral of the calcaneus.

Medial process of the calcaneal tuberosity fracture = plantar fascia avulsion

Compressive or tensile forces.

A small fleck of bone separated from the donor site in the inferior surface of the calcaneal tuberosity or a break in the medial process cortex.

Best seen on the lateral view of the ankle or the lateral view of the calcaneus. 

Posterior surface of the calcaneal tuberosity fracture = Achilles tendon avulsion

Avulsion or shear-compression mechanism of injury.

Best seen on the lateral view of the ankle or the lateral view of the calcaneus. 

Reference: https://ajronline.org/doi/10.2214/AJR.14.14190