Core Nursing Explanation
Key Concept Analysis: This question assesses your ability to identify the
classic clinical sign of a specific orthopedic injury—a
displaced femoral neck fracture. The key is understanding the pathophysiological mechanism: when the femoral neck breaks and the fragments shift (displace), the powerful muscles attached to the proximal femur (like the iliopsoas and external rotators) pull the leg into a characteristic, deformed position. This is a
definitive sign of displacement, unlike more general signs of injury.
Answer Rationale:
Key Point! The correct answer is
External rotation and shortening of the affected leg. This is a pathognomonic finding for a displaced femoral neck fracture. The
shortening occurs because the fracture allows the femoral shaft to ride upward. The
external rotation is caused by the unopposed pull of the external rotator muscles (like the piriformis) on the distal fragment after the fracture disrupts the bone's structural integrity. This combination is highly specific for this diagnosis.
Distractor Analysis:
1.
Watch out for confusion! Pain that increases with passive range of motion is a common finding with many musculoskeletal injuries (sprains, strains, other fractures) and inflammatory conditions. It is not specific to a displaced femoral neck fracture.
2.
Inability to bear weight is a significant finding that indicates a serious injury, but it is not diagnostic. A patient with a severe hip contusion, nondisplaced fracture, or other lower extremity injury may also be unable to bear weight.
4.
Swelling and bruising around the hip joint are expected signs of trauma and soft tissue injury. They are nonspecific and can occur with many types of hip trauma, including contusions or less severe fractures. They do not indicate bone displacement.
Related Concepts: This assessment finding directly informs immediate nursing actions: maintaining limb alignment, avoiding further rotation or movement, and preparing for likely surgical intervention (like hemiarthroplasty or internal fixation). It also highlights the importance of a thorough neurovascular assessment distal to the injury to rule out compartment syndrome or vascular compromise.
Concept Summary
| Concept | Description | Clinical Significance |
| Femoral Neck Fracture | A break in the narrow section of bone connecting the femoral head to the shaft. | Common in older adults with osteoporosis; high risk of avascular necrosis (AVN) of the femoral head. |
| Displaced vs. Nondisplaced | Displaced: bone ends are shifted out of alignment. Nondisplaced: bone is cracked but aligned. | Displacement dictates treatment. Nondisplaced may be treated conservatively; displaced almost always requires surgery. |
| Classic Deformity | Affected leg is shortened and externally rotated. | A definitive physical exam finding that strongly suggests a displaced fracture. |
| Neurovascular Assessment | Check pulses (dorsalis pedis, posterior tibial), capillary refill, sensation, and movement distal to the injury. | Critical nursing priority to detect complications like compartment syndrome or vascular injury. |
Side-by-Side Comparison!
| Finding | Displaced Femoral Neck Fracture | Hip Dislocation (Posterior) | Hip Contusion/Strain |
| Leg Position | Shortened, Externally Rotated | Shortened, Internally Rotated and adducted | Normal position |
| Weight-Bearing | Unable | Unable | May be possible with pain |
| Specificity | Pathognomonic for this fracture type | Pathognomonic for posterior dislocation | Nonspecific |
Anatomy, Physiology & Pharmacology Points
- Anatomy: The femoral neck is a common fracture site due to its relative weakness, especially in osteoporotic bone. The medial circumflex femoral artery, which supplies the femoral head, is often damaged in displaced fractures, leading to avascular necrosis (AVN).
- Physiology (Muscle Pull): The iliopsoas muscle flexes the hip, and the external rotators (e.g., piriformis, obturator internus) externally rotate it. When the femoral neck breaks, these muscles pull the distal fragment, causing the classic deformity.
- Pharmacology: Immediate pain management (IV opioids like morphine, NSAIDs) is crucial. Pre-op antibiotics (e.g., cefazolin) are given to prevent surgical site infection. Post-op, anticoagulants (e.g., enoxaparin) are used for DVT (Deep Vein Thrombosis) prophylaxis.
Memory Tips
- Mnemonic: "Short and Out" for a displaced femoral neck fracture: the leg is Shortened and turned Out (externally rotated).
- Visualize: Imagine the broken thigh bone allowing the leg to roll outward and slide upward toward the hip.
- Associate: Hip Dislocation = leg is shortened and turned In (internally rotated). Fracture = turned Out.
High-Frequency NCLEX Topics
This is a
Core topic for NCLEX-RN. You must know:
1. The
classic signs of common fractures (e.g., Colles' fracture = "dinner fork" deformity).
2.
Priority nursing assessments for any trauma/fracture:
Neurovascular status (the 6 P's: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia).
3.
Patient safety and mobility precautions to prevent further injury.
Watch Out for Question Variations!
- From Sign to Intervention: "The nurse observes external rotation and shortening of a patient's leg after a fall. What is the nurse's priority action?" (Answer: Immobilize the limb in the position found and perform a neurovascular assessment).
- From Assessment to Complication: "A patient with a femoral neck fracture is postoperative day 1. For which complication should the nurse monitor most closely?" (Answer: Fat embolism syndrome or Deep vein thrombosis (DVT)).
- Population Focus: "An 85-year-old patient with osteoporosis sustains a hip fracture. Which finding is most concerning for avascular necrosis?" (This ties the initial injury to its long-term complication).