Ankle joint

In anatomy, the ankle joint is the "joint that is formed by the inferior articular and malleolar articular surfaces of the tibia; the malleolar articular surface of the fibula; and the medial malleolar, lateral malleolar, and superior surfaces of the talus"

Especially in the U.S., it has been the standard of care to X-ray every non-trivial ankle injury. An X-ray will modify treatment only if a fracture exists, so if fracture can be excluded, the cost and radiation exposure of X-rays can be avoided.

This is not to suggest that severe ankle sprains cannot be as or more disabling than fractures. Indeed, obtaining a history is important to assessment; repeated sprains can increase vulnerability to soft tissue injury that may eventually need surgical repair.

Field care

Unless there are visible lacerations or protruding bones, the basic care, even of a minor ankle injury, uses the RICE mnemonic:

• Rest
• Ice
• Compression
• Elevation

NSAIDs are appropriate pain relief for minor injuries; opioids may well be required, but the need for them indicates that a full evaluation is required.

Diagnosis

The Ottawa ankle rules, a clinical prediction rule, can indicate a possible fracture and the need for x-rays (see image): The Ottawa rules are more sensitive than other available clinical prediction rules.

Ankle x-rays may be needed

• "...if there is pain in the malleolar zone and one or more of the following:
  • "Bone tenderness at posterior edge (distal 6 cm) or tip of lateral malleolus"
  • "Bone tenderness at posterior edge (distal 6 cm) or tip of medial malleolus"
  • "Inability to bear weight both immediately after the injury and in the emergency department"

Foot x-rays may be needed

• "...if there is pain in the midfoot zone and one or more of the following:
  • "Bone tenderness at base of fifth metatarsal"
  • "Bone tenderness at navicular bone"
  • "Inability to bear weight both immediately after the injury and in the emergency department"

In diabetics or other patients with potentially impaired leg circulation, evaluation should be more aggressive, with deep vein thrombosis and cellulitis considered.

Treatment

After the first 48 hours, or when swelling has stopped, moist heat is more likely to help than continuing ice, although this should be adapted to patient preference.

For severe sprains, below-knee casts for 10 days may be better than compression bandages. Removable rigid braces may be preferable to casts if the patient is traveling away from medical care, and there is a possibility of compression syndrome.

Severe fractures, and some soft tissue injuries, may need surgical repair.