metabolic bone disease Flashcards
what is Paget’s disease of bone ?
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
what causes Paget’s disease ?
strongly genetic 15-30%
SQSTMI
anglo-saxon
possible chronic viral infection within osteoclast
what are the presenting features of Paget’s disease ?
>40 bone pain occasionally deformity excessive heat over bone neurological complications - deafness elevated serum alkaline phosphatase
how do you treat Paget’s disease
IV bisphosphonate therapy, one off zoledronic acid
do not treat based on ALKP alone and only treat in skull
what are rickets and osteomalacia ?
severe nutritional vitamin D deficiency in child or adult
what is osteogenesis imperfecta ?
genetic disorder of connective tissue (type 1 collagen)
characterised by fragile bones from mild trauma and even acts of daily life
wide ranger between ages - early osteoporosis
what are the different types of osteogenesis imperfecta ?
type 1 - milder form, from walking to presenting as adults
type 2 - lethal by age 1
type 3 - progressive deforming with severe bone dysplasia and poor growth
type 4 - similar to type 1 but more severe
what are other signs of osteogenesis imperfecta ?
growth deficiency defective tooth formation hearing loss blue sclera scoliosis barrel chest ligamentous laxity easy bruising
how do you manage osteogenesis imperfecta ?
surgical - treat fractures
medical - IV bisphosphonates
social
genetic
what is osteoporosis ?
metabolic disease characterised by low bone mass, enhanced bone fragility, increase fracture risk
micro-architectural deterioration
what sex is more at risk of osteoporosis ?
females - 50% have osteoporotic fracture before death
1/5 men
what are endocrine causes of osteoporosis ?
thyrotoxicosis hyper/hypo parathryroidism Cushings hyperprolactinaemia hypopituitarism early menopause
what are rheumatic causes of osteoporosis ?
RA
AS
polymyalgia rheumatica
what are GI causes of osteoporosis ?
IBD
liver disease
malabsorption - chronic pancreatitis, coeliac
what medications can cause osteoporosis ?
steroids PPI enzyme inducting anticonvulsants aromatase inhibitors GnRH inhibitors warfarin
how do you prevent osteoporotic fractures ?
minimise risk factors
good calcium and vitamin D status
fall prevention strategy
medications
who should be treated for osteoporosis based on DXA scan ?
normal above -1 - reassure, lifestyle advice
osteopenia -1 - -2.5, lifestyle advice, treat if previous fracture
osteoporosis below -2.5, lifestyle advice, offer treatment
what drugs can be used for osteoporosis ?
HRT
selective oestrogen receptor modulator SERM
bisphosphonates (main)
denosumab - monoclonal Ab to RANKL, injection 6mth, renal impairment
teriparatide - parathyroid hormone
what are side effects of HRT ?
increased risk of blood clots
increased risk of breast cancer with extender use
increased risk of heart disease if large gap after menopause
what are side effects of SERMs ?
hot flushed if taken close to menopause
increased clotting risk
lack of protection at hip site
what are side effects of bisphosphonates ?
oesophagitis iritis/uveitis ONJ atypical femoral shaft fractures dental problems
need to stop for 1-2 yrs after 10 yrs
what are side effects of denosumab ?
allergy, rash
symptomatic hypocalcaemia if given when vitamin D depleted
ONJ
atypical femoral shaft fractures
what are side effects of teriparatide ?
injection site irritation
rarely hypercalcaemia
allergy
COST
