metabolic bone disease Flashcards
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
more susceptible to deformity and fracture
why does someone get Paget’s disease
strong genetic component
environmental trigger: possibility of chronic viral infection within osteoclast
clinical features of Paget’s
always over 40, usually 60 bone pain: deep seated, worse at night bone deformity excessive heat over pagetic bone neuro complications e.g. nerve deafness long bones
presentation of paget’s disease
isolated elevation of serum alkaline phosphatase
bone pain and local heat
bone deformity or fracture
hearing loss
should paget’s disease be treated in asymptomatic patients
no evidence to treat asymptomatic Paget’s unless in skull or in area requiring surgical intervention e.g. hip replacement with pagetic pelvis
do not treat based on raised alkaline phosphatase alone
what is treatment for Paget’s
IV bisphosphonate therapy - one off zoledronic acid infusion
rarely requires another 3-5yrs after first
rickets and osteomalacia
severe nutritional vitD or calcium deficiency causes insufficient mineralisation
rickets = growing kid osteomalacia = adults when epiphyseal plates closed
what does vitamin D do for bone
stimulates absorption of calcium and phosphate from gut, and calcium and phosphate then become available for bone mineralisation
presentation rickets
stunted growth abnormal bony shape - splayed epiphyses large skull rickety shape bowed legs large abdomen odd shape ribs failure to thrive
osteomalacia presentation
elderly, house bound bone pain muscle weakness increased falls risk micro-fractures on X-ray and little holes skull (pepper pot skull)
treatment of osteomalacia/rickets
calcium and vitamin D supplements
oesteogenesis imperfecta
genetic abnormality of type 1 collagen fibres (connective tissue)
what is osteogenesis imperfecta
fragile bones from mild trauma and even acts of daily life
osteogenesis imperfecta defects in T1 collagen: 1
milder form
when child starts to walk, can present in adults
osteogenesis imperfecta defects in T1 collagen: 2
lethal by age 1
