This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fractures of Metacarpals, Phalanges, Metacarpo-Phalangeal Joints, Subject name: Orthopaedics
[{'content': 'Scaphoid fracture which area has maximum chances of Avascular Necrosis? \nSelect and explain. \nA. Proximal 1/3, B. Middle 1/3, C. Distal 1/3, D. Scaphoid Tubercle Fracture', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) Proximal 1/3* Most of the blood supply to the scaphoid enters distally, so blood supply of scaphoid diminishes proximally. This accounts for the fact that 1% of distal third, 20% of middle third, 40% of proximal third and 100% of proximal pole fractures result in avascular necrosis or non-union of the proximal fragment.Scaphoid blood supplyAVN scaphoid', 'role': 'assistant'}]