Knee: unhappy triad: 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 · Knee: unhappy triad

Sample item

A footballer is tackled from the lateral side with a valgus and external rotation force on a planted foot. Which combination constitutes O'Donoghue's unhappy triad?

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

The answer and the reasoning

B. ACL, medial collateral ligament and medial meniscus

O'Donoghue unhappy triad is rupture of the ACL, the medial collateral ligament and the medial meniscus (although more recent MRI studies show lateral meniscal tears to be more common). It follows a valgus and rotational force.

Option by option

  • A. PCL, lateral collateral ligament and lateral meniscus

    A lateral-side triad is not the described combination.

  • B. ACL, medial collateral ligament and medial meniscus (correct)

    Correct. ACL, MCL and medial meniscus form the classic triad.

  • C. ACL, PCL and patellar tendon

    Patellar tendon injury is not part of it.

  • D. MCL, LCL and popliteus

    Collateral and popliteus injury is a posterolateral corner pattern.

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, ACL, medial collateral ligament and medial meniscus. O'Donoghue unhappy triad is rupture of the ACL, the medial collateral ligament and the medial meniscus (although more recent MRI studies show lateral meniscal tears to be more common).

Why is "PCL, lateral collateral ligament and lateral meniscus" not the answer?

A lateral-side triad is not the described combination.

Why is "ACL, PCL and patellar tendon" not the answer?

Patellar tendon injury is not part of it.

Why is "MCL, LCL and popliteus" not the answer?

Collateral and popliteus injury is a posterolateral corner pattern.

What concept does this question test?

It tests Knee: unhappy triad in Orthopaedics. It follows a valgus and rotational force.

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 Knee: unhappy triad?

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.