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Radial Dysplasia
Radial dysplasia, also known as radial club hand or radial longitudinal deficiency, is a congenital difference occurring in a longitudinal direction resulting in radial deviation of the wrist and shortening of the forearm. It can occur in different ways, from a minor anomaly to complete absence of the radius, radial side of the carpal bones and thumb. Hypoplasia of the distal humerus may be present as well and can lead to stiffness of the elbow. Radial deviation of the wrist is caused by lack of support to the carpus, radial deviation may be reinforced if forearm muscles are functioning poorly or have abnormal insertions. Although radial longitudinal deficiency is often bilateral, the extent of involvement is most often asymmetric. The incidence is between 1:30,000 and 1:100,000 and it is more often a sporadic mutation rather than an inherited condition. In case of an inherited condition, several syndromes are known for an association with radial dysplasia, such as the cardiovascul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectrodactyly
Ectrodactyly, split hand, or cleft hand (derived from Greek ''ektroma'' 'abortion' and ''daktylos'' 'finger') involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly (ectrodactyls) are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet. It is a substantial rare form of a congenital disorder in which the development of the hand is disturbed. It is a type I failure of formation – longitudinal arrest. The central ray of the hand is affected and usually appears without proximal deficiencies of nerves, vessels, tendons, muscles and bones in contrast to the radial and ulnar deficiencies. The cleft hand appears as a V-shaped cleft situated in the centre of the hand. The digits at the borders of the cleft might ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpal Bones
The carpal bones are the eight small bones that make up the wrist (or carpus) that connects the hand to the forearm. The term "carpus" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the wrist is to facilitate effective positioning of the hand and powerful use of the extensors and flexors of the forearm, and the mobility of individual carpal bones increase the freedom of movements at the wrist.Kingston 2000, pp 126-127 In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers (or toes in quadrupeds), whereas those of the metacarpus do. The corresponding part of the foot is the tarsus. The carpal bones allow the wrist to move and rotate vertically. Structure Bones The eight carpal bones may be conceptually organized as either two transverse rows, or three longitudinal columns. When c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radius
In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the spoke of a chariot wheel. as a function of axial position ../nowiki>" Spherical coordinates In a spherical coordinate system, the radius describes the distance of a point from a fixed origin. Its position if further defined by the polar angle measured between the radial direction and a fixed zenith direction, and the azimuth angle, the angle between the orthogonal projection of the radial direction on a reference plane that passes through the origin and is orthogonal to the zenith, and a fixed reference direction in that plane. See also *Bend radius *Filling radius in Riemannian geometry *Radius of convergence * Radius of convexity *Radius of curvature *Radius of gyration ''Radius of gyration'' or gyradius of a body about the axis of r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulnar Dysplasia
Ulnar dysplasia also known as ulnar longitudinal deficiency, ulnar club hand or ulnar aplasia/hypoplasia is a rare congenital malformation which consists of an underdeveloped or missing ulnae bone, causing an ulnar deviation of the entire wrist. The muscles and nerves in the hand may be missing or unbalanced. In severe cases, ulnar digits (e.g. ring and pinky finger) may be missing. Sometimes, radial dysplasia occurs alongside this malformation. This condition occurs in 1 in 100,000 live births. Sometimes, other orthopedic problems occur alongside this malformation, such as scoliosis. Types There are four types of ulnar dysplasia: Type 1: The mildest type of ulnar dysplasia. The ulnae is slightly shorter than average and there is a barely noticeable wrist deviation Type 2: The ulnae is moderately-severely smaller than normal. The radius is deviated and so is the hand Type 3: The ulnae is completely missing. The radius is even more deviated, causing a severe ulnar deviation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metatarsophalangeal Articulations
The metatarsophalangeal joints (MTP joints), also informally known as toe knuckles, are the joints between the metatarsal bones of the foot and the proximal bones (proximal phalanges) of the toes. They are condyloid joints, meaning that an elliptical or rounded surface (of the metatarsal bones) comes close to a shallow cavity (of the proximal phalanges). The ligaments are the plantar and two collateral. Movements The movements permitted in the metatarsophalangeal joints are flexion, extension, abduction, adduction and circumduction. File:The feet of C. H. Unthan, the armless fiddler Wellcome L0034227.jpg, Left: toes adducted (pulled towards the center) and spread (abducted); right, both feet clenched (plantar flexed) File:Footgym rings1.jpg, The upper foot is clenching (plantarflexing) at the MTP joints and at the joints of the toes; the central foot is lifting the toes (dorsiflexing) at the MTP joints; and the foot flat on the ground off to the side is in a neutral position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollicization
{{Short description, Surgically turning an existing finger into a thumb Pollicization (or pollicisation) is a hand surgery technique in which a thumb is created from an existing finger. Typically this consists of surgically migrating the index finger to the position of the thumb in patients who are either born without a functional thumb (most common) or in patients who have lost their thumb traumatically and are not amenable to other preferred methods of thumb reconstruction such as toe-to-hand transfers. During pollicization the index finger metacarpal bone is cut and the finger is rotated approximately 120 to 160 degrees and replaced at the base of the hand at the usual position of the thumb. The arteries and veins are left attached. If nerves and tendons are available from the previous thumb these are attached to provide sensation and movement to the new thumb ("neopollex"). If the thumb is congenitally absent other tendons from the migrated index finger may be shortened and rer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is a medication used to treat a number of cancers (including multiple myeloma), graft-versus-host disease, and a number of skin conditions including complications of leprosy. While it has been used in a number of HIV-associated conditions, such use is associated with increased levels of the virus. It is taken by mouth. Common side effects include sleepiness, rash, and dizziness. Severe side effects include tumor lysis syndrome, blood clots, and peripheral neuropathy. Use in pregnancy may harm the fetus, including resulting in malformation of the limbs. In males who are taking the medication, contraception is essential if a partner could become pregnant. It is an immunomodulatory medication and works by a number of mechanisms, including stimulating T cells and decreasing TNF-α production. Thalidomide was first marketed in 1957 in West Germany, where it was available over the counter. When first r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radius (bone)
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is usually slightly longer than the radius, but the radius is thicker. Therefore the radius is considered to be the larger of the two. It is a long bone, prism-shaped and slightly curved longitudinally. The radius is part of two joints: the elbow and the wrist. At the elbow, it joins with the capitulum of the humerus, and in a separate region, with the ulna at the radial notch. At the wrist, the radius forms a joint with the ulna bone. The corresponding bone in the lower leg is the fibula. Structure The long narrow medullary cavity is enclosed in a strong wall of compact bone. It is thickest along the interosseous border and thinnest at the extremities, same over the cup-shaped articular surface (fovea) of the head. The trabeculae of the spongy tissue are some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apical Ectodermal Ridge
The apical ectodermal ridge (AER) is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signaling center to ensure proper development of a limb. After the limb bud induces AER formation, the AER and limb mesenchyme—including the zone of polarizing activity (ZPA)—continue to communicate with each other to direct further limb development. The position of the limb bud, and hence the AER, is specified by the expression boundaries of Hox genes in the embryonic trunk. At these positions, the induction of cell outgrowth is thought to be mediated by a positive feedback loop of fibroblast growth factors (FGFs) between the intermediate mesoderm, the lateral plate mesoderm and the surface ectoderm. FGF8 in the intermediate mesoderm signals to the lateral mesoderm, restricting the expression of FGF10 through intermediate Wnt signals. Then, FGF10 in the lateral plate mesoderm signals to the surface ectoderm to create the AER, which ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TAR Syndrome
TAR syndrome (thrombocytopenia with absent radius) is a rare genetic disorder that is characterized by the absence of the radius bone in the forearm and a dramatically reduced platelet count. Signs and symptoms * Presents with symptoms of thrombocytopenia, or a lowered platelet count, leading to bruising and potentially life-threatening hemorrhage. * Absence of the radius bone in the forearm with preservation of the thumb. Other common links between people with TAR syndrome include anemia, heart problems, kidney problems, knee joint problems, and frequently milk allergy. Different cases with leukemia in patients with TAR are described in. Genetics This condition requires mutations in both chromosomes.Brodie SA, Rodriguez-Aulet JP, Giri N, Dai J, Steinberg M, Waterfall JP, Roberson D, Ballew BJ, Zhou W, Anzick SL, Jiang Y, Wang Y, Zhu YJ, Meltzer PS, Boland J, Alter BP, Savage SA (2019) 1q21.1 deletion and a rare functional polymorphism in siblings with thrombocytopenia-abse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
