Ossification of Posterior Longitudinal Ligament: A calcification of the posterior longitudinal ligament of the spinal column, usually at the level of the cervical spine. It is often associated with anterior ankylosing hyperostosis.Osteogenesis: The process of bone formation. Histogenesis of bone including ossification.Longitudinal Ligaments: Two extensive fibrous bands running the length of the vertebral column. The anterior longitudinal ligament (ligamentum longitudinale anterius; lacertus medius) interconnects the anterior surfaces of the vertebral bodies; the posterior longitudinal ligament (ligamentum longitudinale posterius) interconnects the posterior surfaces. The commonest clinical consideration is OSSIFICATION OF POSTERIOR LONGITUDINAL LIGAMENT. (From Stedman, 25th ed)Ligamentum Flavum: The paired bands of yellow elastic tissue that connect adjoining laminae of the vertebrae. With the laminae, it forms the posterior wall of the spinal canal and helps hold the body erect.Growth Plate: The area between the EPIPHYSIS and the DIAPHYSIS within which bone growth occurs.Cartilage: A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.Myositis Ossificans: A disease characterized by bony deposits or the ossification of muscle tissue.Chondrocytes: Polymorphic cells that form cartilage.Bone Development: The growth and development of bones from fetus to adult. It includes two principal mechanisms of bone growth: growth in length of long bones at the epiphyseal cartilages and growth in thickness by depositing new bone (OSTEOGENESIS) with the actions of OSTEOBLASTS and OSTEOCLASTS.Epiphyses: The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united.Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Hyperostosis, Diffuse Idiopathic Skeletal: A disease of elderly men characterized by large osteophytes that bridge vertebrae and ossification of ligaments and tendon insertions.Collagen Type X: A non-fibrillar collagen found primarily in terminally differentiated hypertrophic CHONDROCYTES. It is a homotrimer of three identical alpha1(X) subunits.Chondrogenesis: The formation of cartilage. This process is directed by CHONDROCYTES which continually divide and lay down matrix during development. It is sometimes a precursor to OSTEOGENESIS.Calcification, Physiologic: Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.Cranial Sutures: A type of fibrous joint between bones of the head.Ligaments: Shiny, flexible bands of fibrous tissue connecting together articular extremities of bones. They are pliant, tough, and inextensile.Ankylosis: Fixation and immobility of a joint.Cervical Vertebrae: The first seven VERTEBRAE of the SPINAL COLUMN, which correspond to the VERTEBRAE of the NECK.Humerus: Bone in humans and primates extending from the SHOULDER JOINT to the ELBOW JOINT.Spine: The spinal or vertebral column.Skeleton: The rigid framework of connected bones that gives form to the body, protects and supports its soft organs and tissues, and provides attachments for MUSCLES.Periosteum: Thin outer membrane that surrounds a bone. It contains CONNECTIVE TISSUE, CAPILLARIES, nerves, and a number of cell types.Occipital Bone: Part of the back and base of the CRANIUM that encloses the FORAMEN MAGNUM.Osteoblasts: Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.Parietal Bone: One of a pair of irregularly shaped quadrilateral bones situated between the FRONTAL BONE and OCCIPITAL BONE, which together form the sides of the CRANIUM.Osteochondrodysplasias: Abnormal development of cartilage and bone.Bone Morphogenetic Protein 2: A potent osteoinductive protein that plays a critical role in the differentiation of osteoprogenitor cells into OSTEOBLASTS.Core Binding Factor Alpha 1 Subunit: A transcription factor that dimerizes with CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain and is involved in genetic regulation of skeletal development and CELL DIFFERENTIATION.Elbow Joint: A hinge joint connecting the FOREARM to the ARM.Spinal Cord Compression: Acute and chronic conditions characterized by external mechanical compression of the SPINAL CORD due to extramedullary neoplasm; EPIDURAL ABSCESS; SPINAL FRACTURES; bony deformities of the vertebral bodies; and other conditions. Clinical manifestations vary with the anatomic site of the lesion and may include localized pain, weakness, sensory loss, incontinence, and impotence.Fracture Healing: The physiological restoration of bone tissue and function after a fracture. It includes BONY CALLUS formation and normal replacement of bone tissue.Femur: The longest and largest bone of the skeleton, it is situated between the hip and the knee.Antlers: The horn of an animal of the deer family, typically present only in the male. It differs from the HORNS of other animals in being a solid, generally branched bony outgrowth that is shed and renewed annually. The word antler comes from the Latin anteocularis, ante (before) + oculus (eye). (From Webster, 3d ed)Dwarfism: A genetic or pathological condition that is characterized by short stature and undersize. Abnormal skeletal growth usually results in an adult who is significantly below the average height.Tibia: The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.Laminectomy: A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.Total Disc Replacement: The replacement of intervertebral discs in the spinal column with artificial devices. The procedure is done in the lumbar or cervical spine to relieve severe pain resulting from INTERVERTEBRAL DISC DEGENERATION.Bone Morphogenetic Proteins: Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.Ribs: A set of twelve curved bones which connect to the vertebral column posteriorly, and terminate anteriorly as costal cartilage. Together, they form a protective cage around the internal thoracic organs.Decompression, Surgical: A surgical operation for the relief of pressure in a body compartment or on a body part. (From Dorland, 28th ed)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Hypertrophy: General increase in bulk of a part or organ due to CELL ENLARGEMENT and accumulation of FLUIDS AND SECRETIONS, not due to tumor formation, nor to an increase in the number of cells (HYPERPLASIA).Cervical Atlas: The first cervical vertebra.Fibrous Dysplasia, Polyostotic: FIBROUS DYSPLASIA OF BONE affecting several bones. When melanotic pigmentation (CAFE-AU-LAIT SPOTS) and multiple endocrine hyperfunction are additionally associated it is referred to as Albright syndrome.Craniosynostoses: Premature closure of one or more CRANIAL SUTURES. It often results in plagiocephaly. Craniosynostoses that involve multiple sutures are sometimes associated with congenital syndromes such as ACROCEPHALOSYNDACTYLIA; and CRANIOFACIAL DYSOSTOSIS.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Spinal Cord Diseases: Pathologic conditions which feature SPINAL CORD damage or dysfunction, including disorders involving the meninges and perimeningeal spaces surrounding the spinal cord. Traumatic injuries, vascular diseases, infections, and inflammatory/autoimmune processes may affect the spinal cord.Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Calcaneus: The largest of the TARSAL BONES which is situated at the lower and back part of the FOOT, forming the HEEL.Thoracic Vertebrae: A group of twelve VERTEBRAE connected to the ribs that support the upper trunk region.Osteoma: A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). (From Dorland, 27th ed)Alkaline Phosphatase: An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 188.8.131.52.SOX9 Transcription Factor: A SOXE transcription factor that plays a critical role in regulating CHONDROGENESIS; OSTEOGENESIS; and male sex determination. Loss of function of the SOX9 transcription factor due to genetic mutations is a cause of CAMPOMELIC DYSPLASIA.Ulna: The inner and longer bone of the FOREARM.Bone Diseases, DevelopmentalAchondroplasia: An autosomal dominant disorder that is the most frequent form of short-limb dwarfism. Affected individuals exhibit short stature caused by rhizomelic shortening of the limbs, characteristic facies with frontal bossing and mid-face hypoplasia, exaggerated lumbar lordosis, limitation of elbow extension, GENU VARUM, and trident hand. (Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/Omim, MIM#100800, April 20, 2001)Metatarsal Bones: The five long bones of the METATARSUS, articulating with the TARSAL BONES proximally and the PHALANGES OF TOES distally.Bone Matrix: Extracellular substance of bone tissue consisting of COLLAGEN fibers, ground substance, and inorganic crystalline minerals and salts.Femur Head: The hemispheric articular surface at the upper extremity of the thigh bone. (Stedman, 26th ed)Hyperostosis: Increase in the mass of bone per unit volume.Receptor, Fibroblast Growth Factor, Type 3: A fibroblast growth factor receptor that regulates CHONDROCYTE growth and CELL DIFFERENTIATION. Mutations in the gene for fibroblast growth factor receptor 3 have been associated with ACHONDROPLASIA; THANATOPHORIC DYSPLASIA and NEOPLASTIC CELL TRANSFORMATION.Fetal Development: Morphological and physiological development of FETUSES.Fetus: The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.Matrix Metalloproteinase 13: A secreted matrix metalloproteinase that plays a physiological role in the degradation of extracellular matrix found in skeletal tissues. It is synthesized as an inactive precursor that is activated by the proteolytic cleavage of its N-terminal propeptide.Spinal Stenosis: Narrowing of the spinal canal.Bony Callus: The bony deposit formed between and around the broken ends of BONE FRACTURES during normal healing.Osteoclasts: A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.Forelimb: A front limb of a quadruped. (The Random House College Dictionary, 1980)Hip Joint: The joint that is formed by the articulation of the head of FEMUR and the ACETABULUM of the PELVIS.Fractures, Bone: Breaks in bones.GTP-Binding Protein alpha Subunits, Gs: A family of heterotrimeric GTP-binding protein alpha subunits that activate ADENYLYL CYCLASES.Spinal DiseasesOsteochondrosis: Any of a group of bone disorders involving one or more ossification centers (EPIPHYSES). It is characterized by degeneration or NECROSIS followed by revascularization and reossification. Osteochondrosis often occurs in children causing varying degrees of discomfort or pain. There are many eponymic types for specific affected areas, such as tarsal navicular (Kohler disease) and tibial tuberosity (Osgood-Schlatter disease).Spinal Cord Injuries: Penetrating and non-penetrating injuries to the spinal cord resulting from traumatic external forces (e.g., WOUNDS, GUNSHOT; WHIPLASH INJURIES; etc.).Gestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Quadriplegia: Severe or complete loss of motor function in all four limbs which may result from BRAIN DISEASES; SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; or rarely MUSCULAR DISEASES. The locked-in syndrome is characterized by quadriplegia in combination with cranial muscle paralysis. Consciousness is spared and the only retained voluntary motor activity may be limited eye movements. This condition is usually caused by a lesion in the upper BRAIN STEM which injures the descending cortico-spinal and cortico-bulbar tracts.Osteocalcin: Vitamin K-dependent calcium-binding protein synthesized by OSTEOBLASTS and found primarily in BONES. Serum osteocalcin measurements provide a noninvasive specific marker of bone metabolism. The protein contains three residues of the amino acid gamma-carboxyglutamic acid (Gla), which, in the presence of CALCIUM, promotes binding to HYDROXYAPATITE and subsequent accumulation in BONE MATRIX.Sternum: A long, narrow, and flat bone commonly known as BREASTBONE occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head, and neck.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.Collagen Type II: A fibrillar collagen found predominantly in CARTILAGE and vitreous humor. It consists of three identical alpha1(II) chains.Age Determination by Skeleton: Establishment of the age of an individual by examination of their skeletal structure.Elements: Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.Activin Receptors, Type I: One of the two types of ACTIVIN RECEPTORS or activin receptor-like kinases (ALK'S). There are several type I activin receptors. The major active ones are ALK-2 (ActR-IA) and ALK-4 (ActR-IB).Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Acetabulum: The part of the pelvis that comprises the pelvic socket where the head of FEMUR joins to form HIP JOINT (acetabulofemoral joint).X-Ray Microtomography: X-RAY COMPUTERIZED TOMOGRAPHY with resolution in the micrometer range.Bone Diseases: Diseases of BONES.Elbow: Region of the body immediately surrounding and including the ELBOW JOINT.Bone Regeneration: Renewal or repair of lost bone tissue. It excludes BONY CALLUS formed after BONE FRACTURES but not yet replaced by hard bone.Spondylosis: A degenerative spinal disease that can involve any part of the VERTEBRA, the INTERVERTEBRAL DISK, and the surrounding soft tissue.Arthroplasty, Replacement, Hip: Replacement of the hip joint.Maxillofacial Abnormalities: Congenital structural deformities, malformations, or other abnormalities of the maxilla and face or facial bones.Cleidocranial Dysplasia: Autosomal dominant syndrome in which there is delayed closing of the CRANIAL FONTANELLES; complete or partial absence of the collarbones (CLAVICLES); wide PUBIC SYMPHYSIS; short middle phalanges of the fifth fingers; and dental and vertebral anomalies.Osteochondritis: Inflammation of a bone and its overlaying CARTILAGE.Hyoid Bone: A mobile U-shaped bone that lies in the anterior part of the neck at the level of the third CERVICAL VERTEBRAE. The hyoid bone is suspended from the processes of the TEMPORAL BONES by ligaments, and is firmly bound to the THYROID CARTILAGE by muscles.Hip: The projecting part on each side of the body, formed by the side of the pelvis and the top portion of the femur.Joint DiseasesTemporal Bone: Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).Pseudopseudohypoparathyroidism: A form of PSEUDOHYPOPARATHYROIDISM characterized by the same features except for the abnormal response to hormones such as PARATHYROID HORMONE. It is associated with paternally inherited mutant alleles of the ALPHA CHAIN OF STIMULATORY G PROTEIN.Range of Motion, Articular: The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate MUSCLE STRETCHING EXERCISES.Etidronic Acid: A diphosphonate which affects calcium metabolism. It inhibits ectopic calcification and slows down bone resorption and bone turnover.Spinal Osteophytosis: Outgrowth of immature bony processes or bone spurs (OSTEOPHYTE) from the VERTEBRAE, reflecting the presence of degenerative disease and calcification. It commonly occurs in cervical and lumbar SPONDYLOSIS.Hedgehog Proteins: A family of intercellular signaling proteins that play and important role in regulating the development of many TISSUES and organs. Their name derives from the observation of a hedgehog-like appearance in DROSOPHILA embryos with genetic mutations that block their action.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Sphenoid Bone: An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).DislocationsMicroradiography: Production of a radiographic image of a small or very thin object on fine-grained photographic film under conditions which permit subsequent microscopic examination or enlargement of the radiograph at linear magnifications of up to several hundred and with a resolution approaching the resolving power of the photographic emulsion (about 1000 lines per millimeter).In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Cartilage, Articular: A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.Calcinosis: Pathologic deposition of calcium salts in tissues.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Diaphyses: The shaft of long bones.Paraplegia: Severe or complete loss of motor function in the lower extremities and lower portions of the trunk. This condition is most often associated with SPINAL CORD DISEASES, although BRAIN DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; and MUSCULAR DISEASES may also cause bilateral leg weakness.Mandibular Condyle: The posterior process on the ramus of the mandible composed of two parts: a superior part, the articular portion, and an inferior part, the condylar neck.Bone Remodeling: The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.Pubic Symphysis: A slightly movable cartilaginous joint which occurs between the pubic bones.Toes: Any one of five terminal digits of the vertebrate FOOT.Bone Morphogenetic Protein Receptors, Type I: A subtype of bone morphogenetic protein receptors with high affinity for BONE MORPHOGENETIC PROTEINS. They can interact with and undergo PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS, TYPE II. They signal primarily through RECEPTOR-REGULATED SMAD PROTEINS.Pseudohypoparathyroidism: A hereditary syndrome clinically similar to HYPOPARATHYROIDISM. It is characterized by HYPOCALCEMIA; HYPERPHOSPHATEMIA; and associated skeletal development impairment and caused by failure of response to PARATHYROID HORMONE rather than deficiencies. A severe form with resistance to multiple hormones is referred to as Type 1a and is associated with maternal mutant allele of the ALPHA CHAIN OF STIMULATORY G PROTEIN.Radius: The outer shorter of the two bones of the FOREARM, lying parallel to the ULNA and partially revolving around it.Integumentary System: The outer covering of the body composed of the SKIN and the skin appendages, which are the HAIR, the NAILS; and the SEBACEOUS GLANDS and the SWEAT GLANDS and their ducts.Hyperostosis, Sternocostoclavicular: A rare, benign rheumatologic disorder or syndrome characterized by hyperostosis and soft tissue ossification between the clavicles and the anterior part of the upper ribs. It is often associated with the dermatologic disorder palmoplantar pustulosis, particularly in Japan. Careful diagnosis is required to distinguish it from psoriatic arthritis, OSTEITIS DEFORMANS, and other diseases. Spondylitis of pustulosis palmaris et plantaris is one of the possible causes; also, evidence suggests one origin may be bone infection. Bone imaging is especially useful for diagnosis. It was originally described by Sonozaki in 1974.Exostoses, Multiple Hereditary: Hereditary disorder transmitted by an autosomal dominant gene and characterized by multiple exostoses (multiple osteochondromas) near the ends of long bones. The genetic abnormality results in a defect in the osteoclastic activity at the metaphyseal ends of the bone during the remodeling process in childhood or early adolescence. The metaphyses develop benign, bony outgrowths often capped by cartilage. A small number undergo neoplastic transformation.Skin Diseases, Genetic: Diseases of the skin with a genetic component, usually the result of various inborn errors of metabolism.Spinal Fusion: Operative immobilization or ankylosis of two or more vertebrae by fusion of the vertebral bodies with a short bone graft or often with diskectomy or laminectomy. (From Blauvelt & Nelson, A Manual of Orthopaedic Terminology, 5th ed, p236; Dorland, 28th ed)Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Fetal Weight: The weight of the FETUS in utero. It is usually estimated by various formulas based on measurements made during PRENATAL ULTRASONOGRAPHY.Cystostomy: Surgical creation of an opening (stoma) in the URINARY BLADDER for drainage.AxisSesamoid Bones: Nodular bones which lie within a tendon and slide over another bony surface. The PATELLA (kneecap) is a sesamoid bone.Tomography, X-Ray: Tomography using x-ray transmission.Bone Morphogenetic Protein 4: A bone morphogenetic protein that is a potent inducer of bone formation. It also functions as a regulator of MESODERM formation during EMBRYONIC DEVELOPMENT.Cartilage Diseases: Pathological processes involving the chondral tissue (CARTILAGE).Petrous Bone: The dense rock-like part of temporal bone that contains the INNER EAR. Petrous bone is located at the base of the skull. Sometimes it is combined with the MASTOID PROCESS and called petromastoid part of temporal bone.Craniofacial Abnormalities: Congenital structural deformities, malformations, or other abnormalities of the cranium and facial bones.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Embryonic and Fetal Development: Morphological and physiological development of EMBRYOS or FETUSES.Abnormalities, Drug-Induced: Congenital abnormalities caused by medicinal substances or drugs of abuse given to or taken by the mother, or to which she is inadvertently exposed during the manufacture of such substances. The concept excludes abnormalities resulting from exposure to non-medicinal chemicals in the environment.Osteoarthritis: A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.Clavicle: A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone.Choristoma: A mass of histologically normal tissue present in an abnormal location.Thyroid Cartilage: The largest cartilage of the larynx consisting of two laminae fusing anteriorly at an acute angle in the midline of the neck. The point of fusion forms a subcutaneous projection known as the Adam's apple.Ligaments, Articular: Fibrous cords of CONNECTIVE TISSUE that attach bones to each other and hold together the many types of joints in the body. Articular ligaments are strong, elastic, and allow movement in only specific directions, depending on the individual joint.Sternoclavicular Joint: A double gliding joint formed by the CLAVICLE, superior and lateral parts of the manubrium sterni at the clavicular notch, and the cartilage of the first rib.Frontal Bone: The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the NASAL BONE and the CHEEK BONE on each side of the face.Carpal Bones: The eight bones of the wrist: SCAPHOID BONE; LUNATE BONE; TRIQUETRUM BONE; PISIFORM BONE; TRAPEZIUM BONE; TRAPEZOID BONE; CAPITATE BONE; and HAMATE BONE.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Cell Enlargement: Growth processes that result in an increase in CELL SIZE.Cetacea: An order of wholly aquatic MAMMALS occurring in all the OCEANS and adjoining seas of the world, as well as in certain river systems. They feed generally on FISHES, cephalopods, and crustaceans. Most are gregarious and most have a relatively long period of parental care and maturation. Included are DOLPHINS; PORPOISES; and WHALES. (From Walker's Mammals of the World, 5th ed, pp969-70)Femoral Fractures: Fractures of the femur.Hallux: The innermost digit of the foot in PRIMATES.Chondroma: A benign neoplasm derived from mesodermal cells that form cartilage. It may remain within the substance of a cartilage or bone (true chondroma or enchondroma) or may develop on the surface of a cartilage (ecchondroma or ecchondrosis). (Dorland, 27th ed; Stedman, 25th ed)Coccyx: The last bone in the VERTEBRAL COLUMN in tailless primates considered to be a vestigial tail-bone consisting of three to five fused VERTEBRAE.Fracture Fixation, Internal: The use of internal devices (metal plates, nails, rods, etc.) to hold the position of a fracture in proper alignment.Patellar Ligament: A band of fibrous tissue that attaches the apex of the PATELLA to the lower part of the tubercle of the TIBIA. The ligament is actually the caudal continuation of the common tendon of the QUADRICEPS FEMORIS. The patella is embedded in that tendon. As such, the patellar ligament can be thought of as connecting the quadriceps femoris tendon to the tibia, and therefore it is sometimes called the patellar tendon.Embryo, Mammalian: The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.Dura Mater: The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.Chondrodysplasia Punctata, Rhizomelic: An autosomal recessive form of CHONDRODYSPLASIA PUNCTATA characterized by defective plasmalogen biosynthesis and impaired peroxisomes. Patients have shortened proximal limbs and severely disturbed endochondral bone formation. The metabolic defects associated with the impaired peroxisomes are present only in the rhizomelic form of chondrodysplasia punctata. (From Scriver et al, Metabolic Basis of Inherited Disease, 6th ed, p1497)Osteoarthritis, Hip: Noninflammatory degenerative disease of the hip joint which usually appears in late middle or old age. It is characterized by growth or maturational disturbances in the femoral neck and head, as well as acetabular dysplasia. A dominant symptom is pain on weight-bearing or motion.Metacarpus: The region of the HAND between the WRIST and the FINGERS.Extracellular Matrix Proteins: Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).Femur Head Necrosis: Aseptic or avascular necrosis of the femoral head. The major types are idiopathic (primary), as a complication of fractures or dislocations, and LEGG-CALVE-PERTHES DISEASE.Giant Cells, Foreign-Body: Multinucleated cells (fused macrophages), characteristic of granulomatous inflammation, which form around exogenous material in the skin. They are similar in appearance to Langhans giant cells (GIANT CELLS, LANGHANS), but foreign-body giant cells have more abundant chromatin and their nuclei are scattered in an irregular pattern in the cytoplasm.Facial Bones: The facial skeleton, consisting of bones situated between the cranial base and the mandibular region. While some consider the facial bones to comprise the hyoid (HYOID BONE), palatine (HARD PALATE), and zygomatic (ZYGOMA) bones, MANDIBLE, and MAXILLA, others include also the lacrimal and nasal bones, inferior nasal concha, and vomer but exclude the hyoid bone. (Jablonski, Dictionary of Dentistry, 1992, p113)Pubic Bone: A bone that forms the lower and anterior part of each side of the hip bone.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Collagen Type VI: A non-fibrillar collagen that forms a network of MICROFIBRILS within the EXTRACELLULAR MATRIX of CONNECTIVE TISSUE. The alpha subunits of collagen type VI assemble into antiparallel, overlapping dimers which then align to form tetramers.Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.Amputation Stumps: The part of a limb or tail following amputation that is proximal to the amputated section.Germany, WestOsteogenesis, Distraction: Bone lengthening by gradual mechanical distraction. An external fixation device produces the distraction across the bone plate. The technique was originally applied to long bones but in recent years the method has been adapted for use with mandibular implants in maxillofacial surgery.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Synostosis: A union between adjacent bones or parts of a single bone formed by osseous material, such as ossified connecting cartilage or fibrous tissue. (Dorland, 27th ed)Mesenchymal Stromal Cells: Bone-marrow-derived, non-hematopoietic cells that support HEMATOPOETIC STEM CELLS. They have also been isolated from other organs and tissues such as UMBILICAL CORD BLOOD, umbilical vein subendothelium, and WHARTON JELLY. These cells are considered to be a source of multipotent stem cells because they include subpopulations of mesenchymal stem cells.Joint Prosthesis: Prostheses used to partially or totally replace a human or animal joint. (from UMDNS, 1999)Pseudarthrosis: A pathologic entity characterized by deossification of a weight-bearing long bone, followed by bending and pathologic fracture, with inability to form normal BONY CALLUS leading to existence of the "false joint" that gives the condition its name. (Dorland, 27th ed)Neovascularization, Physiologic: The development of new BLOOD VESSELS during the restoration of BLOOD CIRCULATION during the healing process.Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Tendons: Fibrous bands or cords of CONNECTIVE TISSUE at the ends of SKELETAL MUSCLE FIBERS that serve to attach the MUSCLES to bones and other structures.Elephants: Large mammals in the family Elephantidae, with columnar limbs, bulky bodies, and elongated snouts. They are the only surviving members of the PROBOSCIDEA MAMMALS.Mesoderm: The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Osteosclerosis: An abnormal hardening or increased density of bone tissue.Anti-Inflammatory Agents, Non-Steroidal: Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions.They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.Intervertebral Disc: Any of the 23 plates of fibrocartilage found between the bodies of adjacent VERTEBRAE.Indomethacin: A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Thanatophoric Dysplasia: A severe form of neonatal dwarfism with very short limbs. All cases have died at birth or later in the neonatal period.Hip Prosthesis: Replacement for a hip joint.Sacrum: Five fused VERTEBRAE forming a triangle-shaped structure at the back of the PELVIS. It articulates superiorly with the LUMBAR VERTEBRAE, inferiorly with the COCCYX, and anteriorly with the ILIUM of the PELVIS. The sacrum strengthens and stabilizes the PELVIS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Bone Morphogenetic Protein 7: A bone morphogenetic protein that is widely expressed during EMBRYONIC DEVELOPMENT. It is both a potent osteogenic factor and a specific regulator of nephrogenesis.Ilium: The largest of three bones that make up each half of the pelvic girdle.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Hip Dysplasia, Canine: A hereditary disease of the hip joints in dogs. Signs of the disease may be evident any time after 4 weeks of age.Limb Buds: Distinct regions of mesenchymal outgrowth at both flanks of an embryo during the SOMITE period. Limb buds, covered by ECTODERM, give rise to forelimb, hindlimb, and eventual functional limb structures. Limb bud cultures are used to study CELL DIFFERENTIATION; ORGANOGENESIS; and MORPHOGENESIS.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.