Imaging Case of the Week 88

The following ankle x-rays are from a 35 year old patient who sustained a left ankle injury following a fall. She is complaining of pain on the lateral aspect of the ankle and is not weight bearing. What can you observe in the x-rays?

Left ankle AP

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Left ankle mortise view

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Left ankle lateral view

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[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]

The ankle x-rays show fracture of the anterior process of the calcaneum. There is also soft tissue swelling over the lateral malleolus.

Fracture of anterior process of calcaneum

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The following CT image is from the same patient.

CT left foot

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The lateral ankle view below, which shows a healing fracture, was taken approximately 8 weeks into the injury.

Left ankle healing fracture of anterior process

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Fracture of the anterior process of the calcaneum is a missable fracture and is best seen on an oblique foot x-ray.

Mechanism of injury is inversion and plantar flexion of the foot causing avulsion of the bifurcate ligament. The bifurcate ligament connects the anterior process to the cuboid and the navicular.

The patient was treated with cast immobilisation, non-weightbearing and a referral to an orthopaedic specialist for follow up. Indication for ORIF is involvement of >25% of the calcaneocuboid joint.

Our patient was managed conservatively by the specialist.