A patient is brought to the emergency department after a high-impact motor vehicle accident. Upon assessment of the right lower extremity, the nurse observes significant swelling, deformity, and ecchymosis over the thigh. Which additional finding is most characteristic of a displaced femoral shaft fracture?

1. A

   Lengthening of the affected limb

2. B

   Shortening of the affected limb

3. C

   Absence of pain with passive movement

4. D

   Paresthesia in the foot without swelling

Appeared in: NORCET 6 mains-2024

Explanation

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• In a displaced femoral shaft fracture, the structural integrity of the femur is lost.
• The powerful surrounding thigh muscles (quadriceps and hamstrings) go into an involuntary spasm.
• This strong muscular pull causes the distal (lower) bone fragment to slide upwards and overlap with the proximal (upper) fragment, a phenomenon called 'overriding'.
• This overriding of the bone fragments results in a visible and measurable shortening of the affected limb compared to the uninjured one.
• External rotation of the foot and leg is also a common accompanying sign due to the pull of the gluteal muscles.

Why Other Options Were Wrong

• Option A: Limb lengthening does not occur in femoral shaft fractures because the strong muscle pull across the fracture site causes the bone fragments to override, leading to shortening.
• Option C: A fracture of a major long bone like the femur is extremely painful due to rich nerve supply in the periosteum and significant soft tissue damage. Any movement would exacerbate this pain.
• Option D: The question stem already states there is 'significant swelling'. Furthermore, paresthesia is a sign of a complication (neurovascular compromise), not the primary mechanical deformity of the fracture itself.

Related Visual

Clinical Relevance

• Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Clinical signs of a displaced long bone fracture in acute care settings.
• Recognizing limb shortening as a cardinal sign of a displaced femoral fracture is critical for nurses to initiate immediate immobilization (e.g., applying a traction splint) to prevent further soft tissue damage, reduce pain, and minimize blood loss.
• A key nursing priority is frequent and thorough neurovascular assessment of the affected extremity (checking the 5 Ps: Pain, Pallor, Pulselessness, Paresthesia, Paralysis) to detect and report signs of compartment syndrome or arterial injury, which are limb-threatening emergencies.
• A femoral shaft fracture can lead to significant internal hemorrhage (1-1.5 L of blood) into the thigh, potentially causing hypovolemic shock. Nurses must monitor vital signs closely for tachycardia and hypotension.

How to Approach the Question

• First, identify the key elements in the question: 'displaced femoral shaft fracture' and 'most characteristic' finding.
• Visualize the anatomy and forces involved. The femur is the body's longest and strongest bone, surrounded by powerful muscles.
• Apply the principles of pathophysiology. When a long bone's continuous structure is broken (displaced fracture), the muscles that span the break will contract forcefully and without a stable bony strut to oppose them.
• Predict the mechanical result of this muscle contraction. The unopposed pull will cause the broken bone ends to slide past each other (override), leading to a decrease in the total length of the limb.
• This logical deduction points directly to 'shortening' as the most characteristic deformity.
• Evaluate the other options to confirm your choice. 'Lengthening' is physically counterintuitive. 'Absence of pain' contradicts the nature of a major fracture. 'Paresthesia' describes a complication, not the primary deformity.

Concept Tested & Keywords

• Concept Tested: Clinical signs of a displaced long bone fracture
• Stem keywords: femoral shaft fracture, displaced, high-impact motor vehicle accident, swelling, deformity, ecchymosis
• Lead-in keywords: most characteristic
• Clinical cues: High-impact motor vehicle accident suggests a high-energy injury, making a displaced fracture likely.
• Clinical cues: Significant swelling, deformity, and ecchymosis are classic signs of a fracture.

Question ID

Qi1ih1R2Q4JN249bgXeB7g

Copy ID

Reference Book

E6 Medicine Macleod Clinical Examination 15e p. 323-325

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 2030-2032