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 the medial meniscus is rather impossible when the knee joint does not - \nSelect and explain. \nA. Extend, B. Flex, C. Rotate, D. Abduct adduct', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Some guides have given option \'c\' (rotation) as the answer. But their answer is wrong.\nYes; medial meniscus injury occurs due to rotational (twisting) injury, but the rotation is possible only in the flexed knee.\nIt has already been explained that in the extended position of the knee, knee gets locked and rotation is not possible. Therefore, meniscal injury cannot be possible in the extended position.\nIn flexed position, knee gets unlocked and rotation can occur in a flexed position. Therefore, meniscal injury occurs in a flexed position.\n\n"The twisting movement, an important component of the mechanism of injury, is possible only with a flexed knee". - Maheshwari\n\nSo, the meniscal injury is not possible if the knee cannot be flexed.', 'role': 'assistant'}]