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Difficulty: EasyOrthopedic Surgery

Match each specific orthopedic injury with its most commonly associated acute neurovascular physical exam finding.

  • Anterior shoulder dislocationLoss of sensation over the lateral aspect of the shoulder
  • Midshaft humeral fractureInability to extend the wrist against resistance
  • Fibular neck fractureWeakness in foot dorsiflexion and eversion
  • Extension-type supracondylar humerus fractureInability to flex the distal interphalangeal joints of the index finger and thumb

Answer

Anterior shoulder dislocation pairs with lateral shoulder sensory loss (axillary nerve); Midshaft humeral fracture pairs with wrist extension inability (radial nerve); Fibular neck fracture pairs with foot dorsiflexion weakness (common peroneal nerve); Supracondylar humerus fracture pairs with distal finger flexion inability (anterior interosseous nerve).
The correct pairings directly reflect the anatomic relationship between major peripheral nerves and the musculoskeletal structures they traverse. Matching the bone/joint with the adjacent nerve allows for the prediction of the downstream motor and sensory deficits.

Step-by-Step Solution

1
Identify the anatomical location of each orthopedic injury.
Locations: glenohumeral joint, humeral shaft, proximal fibula, and distal humerus.
Knowing the exact site of the fracture or dislocation is the first step to identifying adjacent structures.
2
Recall the neurovascular structures that pass in close proximity to these specific bony landmarks.
Axillary nerve (shoulder), radial nerve (humeral shaft), common peroneal nerve (fibular neck), and anterior interosseous nerve / brachial artery (distal humerus).
Orthopedic injuries most commonly compromise structures that run tightly against the affected bone or joint.
3
Determine the expected physical exam deficit resulting from injury to each identified structure.
Axillary -> lateral shoulder numbness; Radial -> wrist drop; Common peroneal -> foot drop; AIN -> weak 'OK' sign.
This translates anatomical knowledge into the clinical findings presented in the question.

Key Concept

Anatomy of peripheral nerves in relation to common orthopedic injuries
Estimated Time:1m 0s
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Topics

Orthopedic Surgery

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