Ligament

Ligament
Diagram of the right knee.
Typical joint
Details
Latin	Ligamentum (Plural: Ligamenta)
Identifiers
TA	A03.0.00.034
FMA	21496, 30319 70773, 21496, 30319
Anatomical terminology

In anatomy, a ligament is the fibrous connective 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:

• Peritoneal ligament: a fold of peritoneum or other membranes.
• Fetal remnant ligament: the remnants of a fetal tubular structure.
• Periodontal ligament: a group of fibers that attach the cementum of teeth to the surrounding alveolar bone.

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]

Examples

Head and neck Cricothyroid ligament Periodontal ligament Suspensory ligament of the lens Thorax Suspensory ligament of the breast Pelvis Anterior sacroiliac ligament Posterior sacroiliac ligament Sacrotuberous ligament Sacrospinous ligament Inferior pubic ligament Superior pubic ligament Suspensory ligament of the penis

Wrist Palmar radiocarpal ligament Dorsal radiocarpal ligament Ulnar collateral ligament Radial collateral ligament Knee Anterior cruciate ligament Lateral collateral ligament Posterior cruciate ligament Medial collateral ligament Cranial cruciate ligament — quadruped equivalent of anterior cruciate ligament Caudal cruciate ligament — quadruped equivalent of posterior cruciate ligament Patellar ligament

Peritoneal ligaments

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

• The hepatoduodenal ligament, that surrounds the hepatic portal vein and other vessels as they travel from the duodenum to the liver.
• The broad ligament of the uterus, also a fold of peritoneum.

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

• Broström procedure

References

Wikimedia Commons has media related to Ligaments.

Joints Types Fibrous Gomphosis Suture Syndesmosis Interosseous membrane Cartilaginous Synchondrosis Symphysis synovial: Plane joint 1° Hinge joint Pivot joint 2° Condyloid joint Saddle joint 3° Ball and socket joint synostosis by range of motion: Synarthrosis Amphiarthrosis Diarthrosis Terminology Kinesiology Anatomical terms of motion Agonist/Antagonist Motions general: Flexion/Extension Adduction/Abduction Internal rotation/External rotation Elevation/Depression specialized/upper limbs: Protraction/Retraction Supination/Pronation specialized/lower limbs: Plantarflexion/Dorsiflexion Eversion/Inversion Components capsular: Articular capsule Synovial membrane Fibrous membrane Synovial fluid Synovial bursa Articular disk/Meniscus extracapsular: Ligament Enthesis Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics

Joints and ligaments of the head and neck Temporomandibular Capsule Articular disk Lateral Temporomandibular ligament Medial Sphenomandibular ligament Stylomandibular ligament Atlanto-occipital capsule membranes (anterior atlantoöccipital membrane posterior atlantoöccipital membrane) Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics

Joints and ligaments of the human arm Shoulder Sternoclavicular Anterior sternoclavicular Posterior sternoclavicular Interclavicular Costoclavicular Acromioclavicular Syndesmoses: Coracoacromial Superior transverse scapular Inferior transverse of scapula Synovial: Acromioclavicular Coracoclavicular (trapezoid conoid) Glenohumeral Capsule Coracohumeral Glenohumeral (superior, middle, and inferior) Transverse humeral Glenoid labrum Elbow Humeroradial Radial collateral Humeroulnar Ulnar collateral Proximal radioulnar Anular Oblique cord Quadrate Forearm Distal radioulnar Palmar radioulnar Dorsal radioulnar Interosseous membrane of forearm Hand Wrist/radiocarpal Dorsal radiocarpal/Palmar radiocarpal Dorsal ulnocarpal/Palmar ulnocarpal Ulnar collateral/Radial collateral Intercarpal midcarpal Radiate carpal Dorsal intercarpal Palmar intercarpal Interosseous intercarpal Scapholunate Pisiform joint (Pisohamate Pisometacarpal) Carpometacarpal Dorsal carpometacarpal Palmar carpometacarpal thumb: Radial collateral Ulnar collateral Intermetacarpal Deep transverse metacarpal Superficial transverse metacarpal Metacarpophalangeal Collateral Palmar Interphalangeal Collateral Palmar Other Carpal tunnel Ulnar canal Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics

Joints and ligaments of torso Vertebral Syndesmosis Of vertebral bodies anterior longitudinal ligament posterior longitudinal ligament Of vertebral arches ligamenta flava supraspinous ligament nuchal ligament interspinal ligament intertransverse ligament Symphysis intervertebral disc (anulus fibrosus nucleus pulposus) Synovial joint Atlanto-axial Medial: Cruciate ligament of atlas (Transverse ligament of atlas) Alar ligament Apical ligament of dens Tectorial membrane of atlanto-axial joint Lateral: no ligaments anterior atlantoaxial ligament posterior atlantoaxial ligament Zygapophysial no ligaments Lumbosacral iliolumbar ligament Sacrococcygeal anterior sacrococcygeal ligament posterior sacrococcygeal ligament Thorax Costovertebral Head of rib Radiate ligament Intra-articular ligament Costotransverse Costotransverse ligament Lumbocostal ligament Sternocostal interarticular sternocostal ligament radiate sternocostal ligaments costoxiphoid ligaments Interchondral no ligaments Costochondral no ligaments Pelvis Syndesmoses of pelvic girdle Obturator membrane Obturator canal Pubic symphysis superior pubic ligament inferior pubic ligament Sacroiliac anterior sacroiliac ligament posterior sacroiliac ligament interosseous sacroiliac ligament ligaments connecting the sacrum and ischium: sacrotuberous ligament sacrospinous ligament Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics

Joints and ligaments of the human leg Hip femoral (iliofemoral pubofemoral ischiofemoral) head of femur transverse acetabular acetabular labrum capsule zona orbicularis Knee Tibiofemoral Capsule Anterior meniscofemoral ligament Posterior meniscofemoral ligament extracapsular: popliteal oblique arcuate collateral medial/tibial fibular/lateral intracapsular: cruciate anterior posterior menisci medial lateral transverse anterolateral Patellofemoral Patellar ligament Infrapatellar fat pad Tibiofibular Superior tibiofibular anterior of the head of the fibula posterior of the head of the fibula Inferior tibiofibular Anterior tibiofibular Posterior tibiofibular Interosseous membrane of leg Foot Talocrural andankle medial: medial of talocrural joint/deltoid anterior tibiotalar posterior tibiotalar tibiocalcaneal tibionavicular lateral: lateral collateral of ankle joint anterior talofibular posterior talofibular calcaneofibular Subtalar/talocalcaneal anterior/posterior lateral/medial interosseous Transverse tarsal Talocalcaneonavicular dorsal talonavicular plantar calcaneonavicular/spring bifurcated (calcaneonavicular) Calcaneocuboid dorsal calcaneocuboid long plantar plantar calcaneocuboid bifurcated (calcaneocuboid) Distal intertarsal Cuneonavicular plantar dorsal Cuboideonavicular plantar dorsal Intercuneiform plantar dorsal interosseous Other Tarsometatarsal/Lisfranc plantar dorsal Intermetatarsal/metatarsal plantar dorsal interosseous superficial transverse deep transverse Metatarsophalangeal plantar collateral Interphalangeal plantar collateral Arches Longitudinal Transverse Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics

Anatomy of the peritoneum and mesentry General Peritoneum Mesentery Abdominal From ventral mesentery Lesser omentum Hepatoduodenal ligament Hepatogastric ligament Liver Coronary ligament (Left triangular ligament Right triangular ligament Hepatorenal ligament) Falciform ligament (Round ligament of liver and Ligamentum venosum in it, but not of it) From dorsal mesentery Greater omentum Gastrophrenic ligament Gastrocolic ligament Gastrosplenic ligament Mesentery Transverse mesocolon Sigmoid mesocolon Mesoappendix Root of the mesentery Splenorenal ligament Phrenicocolic ligament Folds Umbilical folds Supravesical fossa Medial inguinal fossa Lateral umbilical fold Lateral inguinal fossa Ileocecal fold Abdominal cavity Greater sac Omental bursa Omental foramen General Cystohepatic triangle Hepatorenal recess of subhepatic space Abdominal wall Inguinal triangle Peritoneal recesses Paracolic gutters Paramesenteric gutters Pelvic Uterus/ovaries Broad ligament of the uterus Mesovarium Mesosalpinx Mesometrium) Ovarian ligament Suspensory ligament of ovary Recesses Male Recto-vesical pouch Pararectal fossa Female Recto-uterine pouch Recto-uterine fold (Uterosacral ligament) Vesico-uterine pouch Ovarian fossa Paravesical fossa Spaces Extraperitoneal space Retroperitoneal space Retropubic space Index of digestion Description Anatomy tract glands other Physiology enzymes Development Disease Congenital Neoplasms and cancer Inflammatory bowel disease Gluten sensitivity Other Symptoms and signs eponymous Blood tests Treatment Procedures Drugs anabolic steroids antacids diarrhoea and infection bile and liver functional gastrointestinal disorders laxatives peptic ulcer and reflux nausea and vomiting other Surgery

Fetal vascular remnant ligaments Heart Ligamentum arteriosum Liver Round ligament of liver Ligamentum venosum Umbilical Medial umbilical ligament see also Median umbilical ligament and Lateral umbilical fold

Connective tissue Physiology Soft tissue Fibrosis Scarring Classification Proper Loose Reticular Adipose Brown White Dense Dense irregular connective tissue Submucosa Dermis Dense regular connective tissue Ligament Tendon Aponeurosis Embryonic Mucoid Mesenchymal Specialized Cartilage Bone Composition Cells Resident Fibroblast Fibrocyte Reticular cell Tendon cell Adipocyte Melanocyte Wandering cells Mast cell Macrophage Extracellular matrix Ground substance Tissue fluid Fibers Collagen fibers Reticular fibers: COL3A1 Elastic fibers: Elastin Fibrillin FBN1 FBN2 FBN3 EMILIN1 Elaunin Index of skin Description Anatomy Physiology connective tissue Development Disease Infections by morphology Vesiculobullous Dermatitis and eczema factitial Papulosquamous Urticaria and erythema Radiation-related Pigmentation Mucinoses Keratosis, ulcer, atrophy, and necrobiosis Vasculitis Fat Neutrophilic and eosinophilic Congenital Neoplasms and cancer nevi and melanomas epidermis dermis Symptoms and signs eponymous Terminology Treatment Procedures Drugs antibiotics disinfectants emollients and protectives itch psoriasis other Wound and ulcer Index of muscle Description Anatomy head neck arms chest and back diaphragm abdomen genital area legs Muscle tissue Physiology connective tissue Disease Myopathy Soft tissue Connective tissue Congenital abdomen muscular dystrophy Neoplasms and cancer Injury Symptoms and signs eponymous Treatment Procedures Drugs anti-inflammatory muscle relaxants