Calcaneus series

The calcaneus series is comprised of a lateral and axial (plantodorsal) projection. The calcaneus is the most commonly fractured tarsal bone accounting for ~60% of all tarsal fractures . This series provides a two view investigation of the calcaneus alongside the talar articulations and talocalcaneal joint.

This series provides the first step in the diagnosis of acute calcaneal fractures. Often the series will be the benchmark in the diagnosis of osseous injuries , however, due to the complexity of the region, calcaneus injuries will go on to have further imaging such as computed tomography to define the intricacies of the pathology.

Significant fractures of the calcaneus are resultant of high-energy axial loading; this mechanism has a high association with burst fractures of the lumbar spine .

Indications

Calcaneus radiographs are performed for a variety of indications including:

• fall from a significant height onto feet
• axial loading on the talus during deceleration in a motor vehicle accident 
• inability to weight bear
• violent twisting injuries 
• pathological processes such as osteoporosis, tumors or cysts  

Projections

Standard projections

• lateral view
  • used to measure Böhler's angle between the anterior and posterior aspects of the most superior portion of the calcaneus 
  • articulation with the cuboid and talus are in profile  
• axial view (Harris)
  • the plantar aspect is entirely visual from the posterior tuberosity to the articulation between the calcaneus and talus

Additional projections

• An ankle series and/or foot series may be required after the initial investigation to rule out further pathology. 
• Broden view
  • used to evaluate the posterior subtalar joint
• Canale/Kelly view
  • used to evaluate the talar neck
  • anterior calcaneal process and calcaneocuboid joint well visualized (also calcaneonavicular coalition)