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Difficulty: HardOrthopedic Surgery

A series of patients present to the trauma bay with various acute orthopedic injuries. Match each specific fracture pattern or dislocation with its most likely associated neurovascular deficit observed on physical examination.

  • Anterior shoulder dislocationImpaired shoulder abduction beyond 15 degrees and decreased pinprick sensation over the lateral deltoid
  • Midshaft humeral fractureWeakness in wrist extension and decreased sensation over the dorsal aspect of the first web space
  • Supracondylar humeral fracture with posterolateral displacementInability to form an 'OK' sign due to impaired flexion of the thumb interphalangeal and index distal interphalangeal joints
  • Medial humeral epicondyle fractureWeakness in spreading the fingers and sensory loss over the palmar aspect of the medial one and a half digits
  • Fibular neck fractureInability to evert or dorsiflex the foot with sensory loss over the anterolateral leg and dorsum of the foot

Answer

Anterior shoulder dislocation pairs with axillary nerve deficits; midshaft humeral fracture pairs with radial nerve deficits; posterolateral supracondylar fracture pairs with median/anterior interosseous nerve deficits; medial epicondyle fracture pairs with ulnar nerve deficits; and fibular neck fracture pairs with common peroneal nerve deficits.
Each match correctly pairs a classic orthopedic injury with the peripheral nerve most vulnerable at that specific anatomical site, accurately describing the resulting motor and sensory deficits.

Step-by-Step Solution

1
Analyze each specific orthopedic fracture or dislocation and identify the major peripheral nerve running in closest anatomical proximity to the injury site.
Identified Axillary, Radial, Median (AIN), Ulnar, and Common Peroneal nerves respectively.
Anatomical proximity is the primary determinant of which neurovascular structure is at risk during a fracture or dislocation.
2
Determine the motor and sensory distribution of each identified nerve.
Correlated the nerves with their respective physical exam findings, such as wrist drop for the radial nerve and loss of the 'OK' sign for the anterior interosseous nerve.
Clinical presentation of nerve injury depends strictly on the distal innervation pattern of the compromised nerve.
3
Match the orthopedic injury to the corresponding clinical deficit.
All five pairs are successfully matched based on neuroanatomical principles.
Accurate pairing ensures correct diagnosis and timely intervention for traumatic neuropathies.

Key Concept

Neurovascular complications of orthopedic trauma based on anatomical proximity.
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Orthopedic Surgery

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