In the emergency trauma setting, acute musculoskeletal injuries frequently compromise adjacent anatomical structures. Match each acute orthopedic injury pattern with its most commonly associated critical neurovascular consequence or expected physical examination finding.
- Midshaft humeral fractureWeakness in wrist extension and dorsal web space anesthesia
- Anterior glenohumeral dislocationFlattening of the shoulder contour and lateral deltoid anesthesia
- Fibular head and neck fractureWeakness in ankle dorsiflexion and lateral leg anesthesia
- Posterior tibiofemoral dislocationAsymmetrical or absent dorsalis pedis and posterior tibial pulses
Answer
Midshaft humeral fracture matches with weakness in wrist extension. Anterior glenohumeral dislocation matches with flattening of the shoulder contour. Fibular head and neck fracture matches with weakness in ankle dorsiflexion. Posterior tibiofemoral dislocation matches with asymmetrical or absent distal pulses.
Correct matching pairs are derived directly from classical anatomical relationships tested on the USMLE. The radial nerve's course in the spiral groove links it to the midshaft humerus. The axillary nerve's path through the quadrangular space links it to anterior shoulder dislocations. The common fibular nerve's superficial wrap around the fibula dictates its vulnerability in fibular neck fractures. Finally, the rigid fixation of the popliteal artery makes it the most critical structure evaluated following any knee dislocation.
Step-by-Step Solution
Key Concept
Specific orthopedic injuries reliably predict particular neurovascular deficits based on strict anatomical tethering and proximity of nerves and vessels to bone.