Metabolic Bone Disease Flashcards
What does vitamin D stimulate?
Absorption of calcium and phosphate from the gut, which then become available for bone mineralisation
What is rickets?
Sever nutritional vitamin D or calcium deficiency causes insufficient mineralisation and thus rickets in a growing child
What is osteomalacia?
Severe nutritional vitamin D or calcium deficiency causing insufficient mineralisation in an adult when the epiphyseal lines are closed
What is Paget’s disease?
Localised disorder of bone turnover
Increased bone resorption followed by increased bone formation
Leads to disorganised bone; bigger, less compact, more vascular and more susceptible to deformity and fracture
What are the clinical features of Paget’s disease?
Patient >40 Bone pain Excessive heat over pagetic area Bone deformity Neurological complications (nerve deafness)
What is the presentation of Paget’s disease?
Isolated elevation of serum alkaline phosphatase
Bone pain and local heat
Bone deformity or fracture
Hearing loss
Osteosarcoma development in affected bone
What is the treatment for Paget’s disease?
IV bisphophonate therapy- one off IV zoledronic acid
What is osteogenesis imperfecta?
Genetic disorder of connective tissue characterised by fragile bones from mild trauma due to defects in type 1 collagen
What are the signs and symptoms of osteogenesis imperfecta?
Growth deficiency Defective tooth formation (dentigenesis imperfecta) Hearing loss Blue sclera Scoliosis Barrel chest Ligamentous laxity Easy bruising
What is the management of osteogenesis imperfecta?
Surgical treatment of fractures
IV bisphosphonates to prevent fractures
What is osteoporosis?
Microarchitectural deterioration of bone resulting in increased risk of fracture
What are the risk factors for fractures?
Age
Bone mineral density (BMD)
Falls
Bone turnover
What is FRAX?
Fracture risk assessment tool
What are the limitations of FRAX?
Doesn’t accommodate all known risk factors
Lacks detail on some risk factors
Depends on adequacy of epidemiological information
Does not replace clinical judgement
What are the causes of secondary osteoporosis?
Hyperthyroid, hyperparathyroid, hypoparathyroid
Coeliac
Cystic fibrosis
Myeloma
Rheumatoid arhtitis
Anklyosing spondylitis
Steroids, heparin, warfarin, anticonvulsants
Anorexia nervosa, early menopause, primary ovarian failure
