the medial malleolus is formed by the
The medial malleolus is the prominence on the inner side of the ankle, formed by the lower end of the tibia. The lateral malleolus is the prominence on the outer side of the ankle, formed by the lower end of the fibula.edial malleolus [edit]. The medial surface of the lower extremity of tibia is prolonged downward to form a strong pyramidal process, flattened from without inward-the medial malleolus.