The first meaning is most commonly what is meant by the term "ligament". After briefly discussing the other two types of ligaments, the remainder of this article will focus upon the first type.
|ductus arteriosus||ligamentum arteriosum|
|extra-hepatic portion of the fetal left umbilical vein||ligamentum teres hepatis (the "round ligament of the liver").|
|intra-hepatic portion of the fetal left umbilical vein (the ductus venosus)||ligamentum venosum|
|distal portions of the fetal left and right umbilical arteries||medial umbilical ligaments|
In its most common use, a ligament is a short band of tough fibrous dense regular connective tissue composed mainly of long, stringy collagen fibers. Ligaments connect bones to other bones to form a joint. (They do not connect muscles to bones; that is the function of tendons.) Some ligaments limit the mobility of articulations, or prevent certain movements altogether.
Ligaments are only elastic; when under tension, they gradually lengthen. (Unlike tendons which are inelastic). This is one reason why dislocated joints must be set as quickly as possible: if the ligaments lengthen too much, then the joint will be weakened, becoming prone to future dislocations. Athletes, gymnasts, dancers, and martial artists perform stretching exercises to lengthen their ligaments, making their joints more supple. The term double-jointed refers to people who have more elastic ligaments, allowing their joints to stretch and contort further. The medical term for describing such double-jointed persons is hyperlaxity and double-jointed is a synonym of hyperlax.
The consequence of a broken ligament can be instability of the joint. Not all broken ligaments need surgery, but if surgery is needed to stabilise the joint, the broken ligament can be joined. Scar tissue may prevent this. If it is not possible to fix the broken ligament, other procedures such as the Brunelli Procedure can correct the instability. Instability of a joint can over time lead to wear of the cartilage and eventually to osteoarthritis.