This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'A. 30-year-old male underwent excision of the right radial head. Following surgery, the patient developed inability to extend the fingers and thumb of the right hand. He did not have any sensory deficit. Which one of the following is the\nmost likely cause? \nSelect and explain. \nA. Injury to Posterior interosseus nerve, B. Iatrogenic injury to common extensor origin, C. Injury to anterior interosseus nerve, D. High radial nerve palsy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Radial nerve injury\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 High radial nerve palsy- Injury above the spiral groove.\no\xa0\xa0 Paralysis of all muscles supplied by radial nerve.\no\xa0\xa0 Clinical features\n\nWrist drop, finger drop, thumb drop\nExtension affected of- elbow, wrist, thumb and fingers\nSensation affected of- posterior surface of arm and forearm and lower lateral half of forearm.\n\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Low radial nerve palsy- Injury below the spiral groove.\no\xa0\xa0 Type I- Injury between spiral groove and elbow.\n\nElbow extensors are spared- Triceps and Anconeus.\nWrist, thumb and finger extensors paralysed- wrist drop, thumb drop, finger drop.\nLoss of sensation on dorsal side of first web space.\n\no\xa0\xa0 Type II- Injury below the elbow joint.\n\nElbow and wrist extensors spared\nThumb and finger extensors paralysed.(extensor digitorum, extensor digiti minimi, extensor indicis, extensor pollicis longus, extensor pollicis brevis)- Thumb drop and finger drop.\nLoss of sensation on dorsal side of first web space.\n\n\xa0In radial nerve head surgery, the most common nerve to get injured is posterior interosseous nerve. There is thumb and finger drop. Extension of wrist is spared.', 'role': 'assistant'}]