World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000017874
Reproduction Date:

Title: Ligament  
Author: World Heritage Encyclopedia
Language: English
Subject: Terminologia Histologica, Collagen, Nuchal ligament, Bivalve shell, Adnexa of uterus
Publisher: World Heritage Encyclopedia


Diagram of the right knee.
Typical joint
Latin Ligamentum (Plural: Ligamenta)
TA [1]
FMA FMA:70773
Anatomical terminology

In anatomy, a ligament is the fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua,[1] fibrous ligament, or true ligament.

Ligament can also refer to:

The study of ligaments is known as desmology (from Greek δεσμός, desmos, "bond"; and -λογία, -logia).

Ligaments are similar to tendons and fasciae as they are all made of connective tissue. The differences in them are in the connections that they make; ligaments connect one bone to another bone, tendons connect muscle to bone and fasciae connect muscles to other muscles. These are all found in the skeletal system of the human body. Ligaments cannot usually be regenerated naturally, however there are periodontal ligament stem cells located near the periodontal ligament which are involved in the adult regeneration of periodontal ligament.

Articular ligaments

"Ligament" most commonly refers to a band of dense regular connective tissue bundles made of collagenous fibers, with bundles protected by dense irregular connective tissue sheaths. Ligaments connect bones to other bones to form joints, while tendons connect bone to muscle. Some ligaments limit the mobility of articulations, or prevent certain movements altogether.

Capsular ligaments are part of the articular capsule that surrounds synovial joints. They act as mechanical reinforcements. Extra-capsular ligaments join together in harmony with the other ligaments and provide joint stability. Intra-capsular ligaments, which are much less common, also provide stability but permit a far larger range of motion. Cruciate ligaments occur in pairs of three.

Ligaments are viscoelastic. They gradually strain when under tension, and return to their original shape when the tension is removed. However, they cannot retain their original shape when extended past a certain point or for a prolonged period of time. 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 hypermobility refers to people with more-elastic ligaments, allowing their joints to stretch and contort further; this is sometimes still called double-jointedness.

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 repaired. 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.

Artificial Ligaments

One of the most often torn ligaments in the body is the anterior cruciate ligament (ACL). The ACL is one of the ligaments crucial to knee stability and is therefore necessary for human mobility. Because of its importance in mobility, it is necessary for the ACL to be repaired promptly with good quality substitutes. This re-constructive surgery has been performed countless times, now new techniques are being used. One of these techniques is the replacement of the ligament with an artificial material. An artificial ligament is a reinforcing material that is used to replace a torn ligament, such as the ACL. Artificial ligaments are a synthetic material composed of a polymer, such as polyacrylonitrile fiber, polypropylene, PET (polyethylene terephthalate), or more commonly used today, polyNaSS poly(sodium styrene sulfonate).[2] Scientists at the Ligament Augmentation & Reconstruction System (LARS) in France have come up with a workable solution to artificial ligaments.

The ACL reconstructive surgery uses a technique called grafting to attach the polymer to the bone. By grafting a bioactive polymer polyNaSS on a polyethylene terephalate device, commonly used in ACL reconstruction, it optimizes the adhesion and distribution of human fibroblasts. In other words the strength and organization of the fibers is increased and the production of fibroblast collagen is increased when the ligament has been bio-integrated with polyNaSS. This new technique is being used on animals and in in-vitro studies today but, the first official medical surgery has yet to occur.

The difficulty behind artificial ligaments is making the polymers biocompatible. Designing the polymer’s properties to be able to withstand all the different types of fatigue is an obstacle that researchers are facing.[3] The polyethylene (PET) and poly (sodium styrene sulfonate) polymers are categorized as Viscoelastic, meaning after the material experiences large amounts of stress it will retain its original properties. Another large issue with biocompatibility and artificial ligaments, is creating a polymer that is non-reactive with inside bodily fluids.

Creating a polymer and coating it with specific substances can make the polymer biocompatible, as well as speed the recovery process. Bio glass 58s, hyaluronic acid, and cationized gelatin are a few coatings that aid the reconstructive process. [4]Bio glass for example is used for strengthening the connection between the polymer and the bone.[5]


Peritoneal ligaments

Certain folds of peritoneum are referred to as ligaments. Examples include:

Fetal remnant ligaments

Certain tubular structures from the fetal period are referred to as ligaments after they close up and turn into cord-like structures:

Fetal Adult
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

See also


  1. ^ "ligament" at Dorland's Medical Dictionary
  2. ^ Lessim, Soucounda, et al. "PolyNaSS bioactivation of LARS artificial ligament promotes human ligament fibroblast colonisation in vitro." Bio-Medical Materials& Engineering 23, no. 4 (June 2013): 289-297. Academic Search Complete, EBSCOhost (accessed April 17, 2014).
  3. ^ Hukins, D. W., Leahy, J. C., & Mathias, K. J. Biomaterials: defining the mechanical properties of natural tissues and selection of replacement materials, 629-636. Retrieved December 22, 1998, from
  4. ^ Acta Biomaterialia (2012), 8, (11), 4007-4019. Publisher: (Elsevier Ltd., ) CODEN:ABCICB ISSN:1742-7061.
  5. ^ Applied Surface Science (2011), 257, (22), 9371-9376. Publisher: (Elsevier B.V., ) CODEN:ASUSEE ISSN:0169-4332.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.