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: Orthopaedics
[{'content': 'Injury to radial nerve in the lower part of spiral groove - \nSelect and explain. \nA. Spares nerve supply to extensor carpi radialis longus, B. Results in paralysis of anconeus muscle, C. Leaves extensions at elbow joint intact, D. Weakens pronation movement', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Radial nerve injury\n\nRadial nerve injury may be high or low.\n\n1) High radial nerve palsy\n\nThe injury is before the spiral groove\nAll muscles supplied by radial nerve are paralysed.\n\n2) Low radial nerve palsy\n\nThe injury is after the spiral groove.\nLow radial nerve palsy may be of two types.\n\ni) Type I: - Injury occurs between the spiral groove and elbows joint. Muscles involvement is : -\na)Elbow extensors (Triceps, anconeus) are spared.\nb)Wrist, elbow and finger extensors are paralysed.\nc) Sensory loss in first web space (on dorsal side)\nii) Type II: - Injury occurs below the elbow joint.\na) Elbow extensors (triceps, anconeus), Brachioradialis and wrist extensors (ECRL) are spared.\nb) Finger extensors (extensor digitorum, extensor digit minimi, extensor indices) and thumb extensors (extensor pollicis longus & brevis) are paralysed.\nc) Sensory loss in first web space ( on dorsal side).', 'role': 'assistant'}]