The deltoid ligament is a strong ligament that connects the tibia bone to the tarsal bones of the foot. It provides support and stability to the inner side of the ankle joint. Synonyms for the deltoid ligament include medial collateral ligament, medial ligament of ankle, and tibiotalar ligament. The medial collateral ligament is the common term used by healthcare professionals and is often abbreviated as MCL. The medial ligament of ankle is another name for the deltoid ligament because of its anatomical location. The tibiotalar ligament refers to the specific part of the delta ligament that connects the tibia bone to the talus bone of the foot.