Fractures and dislocations: os trigonum syndrome: practice question

A Orthopaedics question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Orthopaedics · Fractures and dislocations: os trigonum syndrome

Sample item

A ballet dancer has deep pain at the back of the ankle when she goes fully on point. A lateral radiograph shows a small accessory ossicle behind the talus. What is the diagnosis?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Posterior ankle impingement (os trigonum syndrome)

The os trigonum is an accessory ossicle or enlarged posterolateral talar process that can be pinched between the tibia and the calcaneus in forced plantarflexion. Dancers and footballers are affected. Treatment is rest and injection, with excision if symptoms persist.

Option by option

  • A. Anterior talofibular ligament sprain

    An anterior talofibular sprain causes lateral swelling after an inversion injury.

  • B. Posterior ankle impingement (os trigonum syndrome) (correct)

    Correct. Pain at full plantarflexion with an os trigonum is posterior impingement.

  • C. Sever disease

    Sever disease is calcaneal apophysitis in children, causing heel pain on running.

  • D. Achilles tendinopathy

    Achilles tendinopathy gives pain and thickening of the tendon above the heel, not deep ankle pain with an ossicle.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Orthopaedics questions

Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is B, Posterior ankle impingement (os trigonum syndrome). The os trigonum is an accessory ossicle or enlarged posterolateral talar process that can be pinched between the tibia and the calcaneus in forced plantarflexion.

Why is "Anterior talofibular ligament sprain" not the answer?

An anterior talofibular sprain causes lateral swelling after an inversion injury.

Why is "Sever disease" not the answer?

Sever disease is calcaneal apophysitis in children, causing heel pain on running.

Why is "Achilles tendinopathy" not the answer?

Achilles tendinopathy gives pain and thickening of the tendon above the heel, not deep ankle pain with an ossicle.

What concept does this question test?

It tests Fractures and dislocations: os trigonum syndrome in Orthopaedics. Dancers and footballers are affected. Treatment is rest and injection, with excision if symptoms persist.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Fractures and dislocations: os trigonum syndrome?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.