Fractures and dislocations: locking plate principle: 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: locking plate principle

Sample item

An osteoporotic 70-year-old has a comminuted distal femur fracture fixed with a locking plate. What is the key advantage of locking screws in such bone?

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

The answer and the reasoning

C. The screw heads thread into the plate, forming a fixed-angle construct that does not depend on plate-bone compression

Locking screws engage the plate and form a fixed-angle internal fixator. The construct does not rely on friction between plate and bone, so it keeps working in osteoporotic bone and spares the periosteal blood supply under the plate. It gives relative stability with callus healing, not primary healing.

Option by option

  • A. They give absolute stability with primary bone healing

    Locking plates in bridging mode give relative stability and healing with callus, not absolute stability.

  • B. They allow smaller screws that need no pre-drilling

    Locking screws still require pre-drilling, and their size is not the advantage.

  • C. The screw heads thread into the plate, forming a fixed-angle construct that does not depend on plate-bone compression (correct)

    Correct. The fixed-angle plate-screw construct holds in weak bone and does not need the plate to press on the periosteum.

  • D. They generate interfragmentary compression across every fracture line

    Compression is produced by lag screws or compression plating, not by the locking mechanism.

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.

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Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is C, The screw heads thread into the plate, forming a fixed-angle construct that does not depend on plate-bone compression. Locking screws engage the plate and form a fixed-angle internal fixator.

Why is "They give absolute stability with primary bone healing" not the answer?

Locking plates in bridging mode give relative stability and healing with callus, not absolute stability.

Why is "They allow smaller screws that need no pre-drilling" not the answer?

Locking screws still require pre-drilling, and their size is not the advantage.

Why is "They generate interfragmentary compression across every fracture line" not the answer?

Compression is produced by lag screws or compression plating, not by the locking mechanism.

What concept does this question test?

It tests Fractures and dislocations: locking plate principle in Orthopaedics. The construct does not rely on friction between plate and bone, so it keeps working in osteoporotic bone and spares the periosteal blood supply under the plate. It gives relative stability with callus healing, not primary healing.

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: locking plate principle?

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.