Radiography: tarsus and hindfoot

• A high definition film-screen combination is required.
• A grid is not required.
• kV should not exceed about 50.
• Soft tissues should be included.
• A radiograph including both limbs is useful for comparison.
• General anesthesia or sedation is generally recommended.
• The film should be correctly exposed and developed, and free from movement blur and artefact.
• The anatomical marker must be clearly visible, along with the patient's identification, the date, and the name of the hospital or practice.
  Print off the Owner factsheet Xrays and ultrasound to give to your clients.

Uses

• Fracture Limb fracture  .
• Dislocation  .
• Tarsal valgus/varus but full length tibia/fibula views including the tarsus may be preferable.
• Investigation of joint effusion/swelling.
• Degenerative joint disease.
• Neoplasia: bony, or soft tissue invading bone.
• Septic arthritis  .

Advantages

• Non-invasive.
• Straightforward.

Technical problems

• Small tarsal bones and superimposition of the calcaneus may make some tarsal conditions difficult to detect.

Time required

Preparation

• Dependent upon the method of chemical restraint (GA or sedation).

Procedure

• 10-15 min, or longer, dependent upon skill of radiographer.

Decision taking

Criteria for choosing test

Is the examination appropriate?

• Can you make the diagnosis without it?
• Can it tell you what you want to know?
• Will your management be affected by the radiological findings?

Choosing the right projections

• Lateral:
  • Standard projection  .
  • Important for the tarsus, when looking for fractures or dislocation  .
  • Shows soft tissue swelling/joint effusion.
  • Can show fractures and displacement of metatarsals and phalanges, but obliques may be of more use.
• Dorsoplantar:
  • Standard projection .
  • More use than the lateral in the foot, as metatarsals and phalanges are not overlying each other .
  • Important in the tarsus for fractures and dislocations .
  • Shows joint effusion/soft tissue swelling.
• Dorsolateral-plantaromedial oblique/dorsomedial-plantarolateral oblique:
  • Supplementary views.
  • Can be important in the tarsus, for giving full information on fractures and dislocations.
  • Can be very useful in the foot for showing metatarsals and phalanges in a different plane from the dorsoplantar, but without as much overlapping as in the lateral.
• Stressed views of the tarsus - forced abduction or adduction, forced flexion or extension:
  • Supplementary views.
  • Useful for confirming or assessing extent of tarsal instability .