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Difficulty: MediumOrthopedic Surgery

Match the following specific orthopedic injuries with their most commonly associated neurological deficit or physical examination finding.

  • Anterior shoulder dislocationWeakness of the deltoid muscle and numbness over the lateral shoulder
  • Midshaft humerus fractureWeakness of wrist extension and numbness over the dorsal first web space
  • Medial epicondyle fractureWeakness of finger abduction and numbness over the palmar fifth digit
  • Fibular neck fractureWeakness of ankle dorsiflexion and numbness over the dorsum of the foot
  • Lunate dislocationWeakness of thumb opposition and numbness over the palmar first three digits

Answer

Each orthopedic injury matches with the neurological deficit corresponding to the nerve located in direct anatomical proximity to the fracture or dislocation site.
Correct matching requires detailed anatomical knowledge of peripheral nerve courses. The axillary nerve wraps around the surgical neck of the humerus (injured in shoulder dislocations). The radial nerve courses through the spiral groove (injured in midshaft humerus fractures). The ulnar nerve runs posterior to the medial epicondyle. The common peroneal nerve wraps around the fibular neck. The median nerve passes through the carpal tunnel, directly anterior to the lunate.

Step-by-Step Solution

1
Identify the anatomical location of each orthopedic injury.
Locations isolated: Glenohumeral joint, humeral shaft, elbow (medial aspect), proximal fibula, and volar wrist.
Neurological complications in orthopedics are highly predictable based on local anatomy.
2
Determine the specific nerve that passes adjacent to the injured bone or joint.
Axillary nerve (shoulder), radial nerve (humeral shaft), ulnar nerve (medial epicondyle), common peroneal nerve (fibular neck), and median nerve (carpal tunnel).
Nerves tethered to bone or passing through tight compartments are most vulnerable to mechanical trauma.
3
Correlate the specific nerve with its downstream motor and sensory functions.
Matches established between the nerve injury and the resulting specific weakness (e.g., foot drop, wrist drop) and sensory loss patterns.
Physical examination findings confirm the specific nerve involvement.

Key Concept

Neurovascular Complications of Fractures and Dislocations
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Topics

Orthopedic Surgery

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