Introduction to Common Bone Disorders
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
INTRODUCTION TO COMMON BONE DISORDERS INTRODUCTION TO COMMON BONE DISORDERS NUR HANISAH ZAINOREN SERIAL NO. 55 Objective By the end of this seminar, we should be able to understand: Bone and it’s importance Division of bone disorders Brief characteristics of each bone disease What is Bone? Bone is living tissue that provides shape and support for the body, as well as protection for some organs. Bone also serves as a storage site for minerals and provides the medium(marrow) for the development and storage of blood cells. Bone disease Refers to the medical conditions which affect the bone. It is a condition that damages the skeleton and makes bones weak and prone to fracture Congenital Disease of Bone Dysostoses (Congenital Malformations) Due to mutations in homeobox genes affecting localized migration and condensation of primitive mesenchymal cells. Result in the absence of bones, supernumerary bones, or abnormal fusion of bones. Dysplasias (Abnormalities in bone organogenesis) Mutations that interfere with bone or cartilage growth and maintainance of normal matrix components. Result in achondroplasia, osteogenesis imperfecta and osteopetrosis. 1. Osteogenesis Imperfecta Brittle Bone Disease Caused by abnormal type I collagen synthesis resulting in bone fragility and susceptibility to fractures. The words "osteogenesis imperfecta" mean bone that is imperfectly made from the beginning of life 7 2. Achondroplasia Point mutation in the fibroblast growth factor receptor 3 (FGFR3) that results in its constitutive activation. Inhibits chondrocyte proliferation Suppress expansion of normal epiphyseal growth plate Severely stunted long bone growth Normal epiphyseal growth plate expansion is suppressed and long bone growth is severely stunted 8 3. Osteopetrosis A group of rare genetic disorders characterized by reduced osteoclast-mediated bone resorption defective bone remodelling Result in dense but architecturally unsound bone Acquired/Metabolic Bone Disease Disorders of bone strength, usually caused by abnormalities of minerals (such as calcium or phosphorus), vitamin D, bone mass or bone structure. Osteoporosis Paget Disease (Ostitis Deformans) Rickets and Osteomalacia Hyperparathyroidism 1. Osteoporosis The most common bone disease. This condition is caused by a reduction in bone density, which leads to more fragile bones and a higher risk of fractures. 11 2. Paget Disease (Ostitis Deformans) The bone remodeling is disturbed and not synchronized. The net effect of this process is a gain in bone mass ; however, the newly formed bone is disordered and lacks strength This unique skeletal disease is characterised by repetitive episode of frenzied, regional osteoclastic and bone resorption (osteoclastic stage), followed by exuberant bone formation (mixed osteoclastic-osteoblastic stage), and finally by an apparent exhaustion of cellular activity (osteosclerotic stage). 12 3. Rickets and Osteomalacia Manifestations of vitamin D deficiency or its abnormal metabolism Defective bone mineralization overabundant non-mineralised osteoid This contrasts with osteoporosis, where the mineral content of the remaining bone is normal, but the total bone mass is decreased. 13 4. Hyperparathyroidism Primary or secondary over production of PTH (hyperparathyroidism) Increased osteoclast activity and bone resorption fractures and deformities Arthritis Arthritis is one of the most common conditions in the world. Arthritis literally means joint inflammation. CONCLUSION Importance of bones: Support Protection Storage site Medium Division of bone disorders: Congenital Acquired References Robbins Basic Pathology, 8th Edition, Kumar, Elsevier http://medicalcenter.osu.edu/patientcare/healthcare_services/bone_disorders/Pages/index.aspx http://www.interactive-biology.com/3869/overview-of-three-common-bone-disorders-osteoarthritis-rheumatoid-arthritis-and-osteoporosis/ http://www.surgeongeneral.gov/library/reports/bonehealth/factsheet1.pdf THANK YOU Any Question?