Wednesday, June 1, 2011

Osteogenesis imperfecta

Osteogenesis imperfecta, or brittle bone disease is one of the most common skeletal dysplasia. It is a generalized disease of connective tissue which can occur through one or more of the following elements: blue sclera, triangular face, macrocephaly, deafness, defective dentition, barrel chest, scoliosis, limb deformities, fractures, joint laxity and retarded the growth.Additional Features such as constipation and excessive sweating may also occur.
In osteogenezis flawed pathological changes are observed in all tissues in which type 1 collagen is a major component, such as bone, ligementele, dentin and whites. The main flaw is quantity or quality of type 1 collagen. Mutations in genes encoding collagen type 1 affects one or two genes, comprises more than 80% of cases of osteogenesis imperfecta.Nonortopedice causes of morbidity in type I and IV osteogenesis joint laxity, which causes chronic joint pain, deafness and brain compression. Child care often requires the type III progressive orthopedic deformities due. Bipedal walking and position are impossible because of spinal compression and scoliosis.Progressive thoracic deformities are associated with recurrent pneumonia patient's limited life expectancy. Life expectancy for all patients except those with type III is shortened. Type II is lethal prenatally.
Morbidity and mortality associated with osteogenesis imperfecta can vary widely depending on genotype. Variability depends on sustained mutations. Virtual body shows multiple fractures in all bones. Perinatal form is fatal in a few hours after birth, although some babies can survive a few months. Osteogenesis imperfecta is a mild form in which adults who have not yet suffered a fracture or fractures to the doctor because other family members. Between the two forms of disease there is a continuum of severity.
Until recently the surgical correction of deformities, physiotherapy and support ortotica were the main therapeutic options for osteogenesis imperfecta. With a deeper understanding of molecular mechanisms of disease, has won popularity and medical treatment to increase bone mass and bone hardness.Bisphosphonates are used, pamidronate, which inhibits osteoclast-mediated bone resorption by binding to hydroxyapatite.Significantly improves the disease type III, IV by decreasing the frequency of fractures, increasing bone density, decreased bone pain and increase height. It is administered growth hormone to stimulate osteoclast function, recombinant human parathyroid hormone, bone marrow transplant.
Signs and symptoms
There are seven forms of osteogenesis imperfacta described.
Osteogenesis imperfecta - type I:This is the most easy and common. Patients have blue sclera, bone fragility variable degree, moderate bone deformity and premature deafness. Weight at birth tends to be normal, although one or more bones are broken. Fractures are the first time in the old age, when the child begins to walk. These fractures heal well, though sometimes described hypertrophic callus. Fractures tend to diminish in frequency during puberty, but increased with the advancement in life. Affecting the axial skeleton in the form of scoliosis or kyphosis is seen in 20% of cases. Dentinogeneza imperfecta type 1B disease is characteristic.
Osteogenesis imperfecta - type II:A few children affected with type II is born with dwarfism, blue sclera and legs short, thick. The disease is usually fatal at birth, but some children survive for several months. Multiple fractures are evident, and long bones are short.
Osteogenesis imperfecta - type III:Children with type III disease are born with severe bone fragility and multiple fractures at birth, although their weight at birth tends to be normal. Whites are blue at birth but is normalized through the years, becoming white as an adult. Dentinogeneza imperfecta is common. Thorax and ribs are avoided, with few fractures.Thickening of long bones is increased frequency and multiple fractures are seen late in life. The result is a short frame and barrel chest with pectus carinatum. Classic radiographic appearance of bone in popcorn that cause fractures in different locations endocondrala islands of ossification. With age, the ossification tend to disappear leaving a wide radiolucenta epiphysis. Axial skeleton is also involved with platispondilie and cifoscolioza.Affected children tend to become addicted to the trolley.
Osteogenesis imperfecta - type IV:Children with type IV disease have white sclera with moderate bone fragility and deformity. Clinically similar to type I osteogenesis, except for this white whites. Damage takes the form cifoscoliozei axial skeleton. Dentinogeneza is observed in type IVB osteogenesis.
Osteogenesis imperfecta - type V:It is an autosomal dominant condition with similar severity with type IV disease but predisposed to callus formation hyperplasia. The characteristic elements are intraosseous membrane ossification of the arms and legs, with limited pronation and supinatie and metaphyses in patients radiopaque band on the rise.
Osteogenesis imperfecta - type VI:Type VI is similar to type II and IV but distinct histology, including the formation of defective bone mineralization hiperosteoid.
Osteogenesis imperfecta - type VII:It described the isolation and osteogenesis imperfecta is clinically similar to type II and IV.
Other rare types of osteogenesis imperfecta include:Osteoporosis-pseudogliomaBruck-syndromeCole-Carpenter syndrome.
Complications of osteogenesis imperfecta:They are joint laxity, which causes chronic joint pain, deafness and brain compression. Child care often requires the type III progressive orthopedic deformities due. Bipedal walking and position are impossible because of spinal compression and scoliosis. Progressive thoracic deformities are associated with recurrent pneumonia patient's limited life expectancy. Life expectancy for all patients except those with type III is shortened.

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