You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A 23 year old profession footballer suffered a twisting injury to his right ankle. On examination, there is a lot of swelling around the medial malleolus but x-ray doesn't show any fracture. The structure injured could be and explain in detail?
(Refer: Manish Kumar Varshney's Essential Ohopedics Principles & Practice, 1st edition, pg no. 1265 - 1267)