This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Peripheral Nerve Injury, Subject name: Orthopaedics
Finger drop with no sensory loss is an injury of? 
Select and explain. 
A. High radial nerve, B. Low radial nerve, C. Posterior interosseous nerve, D. Superficial nerve
C: Posterior interosseous nerve
Answer: C: Posterior interosseous nerve 
Explanation: High radial nerve injury - brachioradialis paralyzed+ wrist drop + finger drop + sensory loss Low radial nerve injury - wrist drop + finger drop + sensory loss ( brachioradialis is spared) PIN injury - finger drop Pure motor nerveand hence there is no sensory loss in its injury. Patient cannot extend the metacarpophalangeal joints but wrist extension is preserved as extensor carpi radialis longus is spared Superficial - sensory loss