Ankle series

The ankle series is comprised of an APAnteroposterior (AP), obliqueMortise and lateralLateral radiograph. The series is often used in emergency departments to evaluate the distal tibia, distal fibula and is predominantly employed inthe talus; forming the evaluationankle joint.

Indications

• Ankle trauma
• Bony tenderness at the posterior edge or the tip of trauma.the lateral malleolus
• Bony tenderness at the posterior edge or the tip medial malleolus
• Inability to weight bear
• Non traumatic ankle pain

Projections

Standard projections

• AP
  • Demonstrates the ankle in it's natural anatomical position
• AP mortiseMortise view
  • AP with the foot internally rotated approximately 10° (often this correlates with fifth toe and heel vertical alignment)
  • must includeInternal rotation projects the base of the 5th metatarsal 
  • by rotating the foot, the syndesmosis is ('opened up', projecting the distal fibula off the medial tibial plafond therebyresulting uniformity of the joint space allowing for assessment of the distal tibiofibular syndesmosis
  • The base of the 5^th metacarpal is always included
• lateralLateral
  • Projection 90° to the mortise view
  • Demonstrates the calcaneum and talus in full profile
  • must include the base of the 5th metatarsal
  • by elevating the toes slightly, the lateral malleolus is projected over the posterior one third of the tibia
  • this slight rotation can be increased or decreased if there is concern of a subtle posterior malleolar fracture

Additional projections

If an isolated distal tibial medial malleolus fracture is noted or a significant widening of the mortise joint a Knee series should be performed to rule out a combination spiral fracture of the proximal fibula.

Internal or external stress arecan be performed to assess for dynamic widening of the syndesmosis indicating ligamentous injury.