clinical aspects of bone disease Flashcards
what is the definition of osteoporosis?
a systemic skeletal disease with low bone mass increasing fragility and susceptibility to fracture
what are the types of osteoporosis?
type 1: post menopausal
Type II: senile
secondary
who tends to get type I osteoporosis?
Post menopausal women around 10 years after
what causes type I osteoporosis?
Low levels of oestrogen after post menopause
what bone is affected in type I osteoporosis?
trabecular bone and there is accelerated loss
who tends to get type II osteoporosis?
equally men and women over 70
what are the causes of type II osteoporosis?
nutrition and delayed physical activity
what bone is lost in type II osteoporosis?
both trabeculae and corticol
what bone is lost in secondary osteoporosis?
both trabecular and cortical
what are the main ‘ACCESS’ risk factors for osteoporosis ?
A- alcohol use C- corticosteroid use C- calcium low E- estrogen low S- smoking S- sedentary lfiestyle
other than the ‘ACCESS’ risk factors for osteoporosis?
- family history
- rheumatoid arthritis
- thyroid or liver disease
- spinal cord injury
- nutrition
- thyroid replacement
- ant acids
- long term anti convulsant use
what is the normal presentation of osteoporosis?
often silent but get kyphosis and fractures
what are DEXA T scores?
SD is to the young normal mean bone density from a population of 20-30 year olds Caucasian women
what is Z score in DEXA?
the age matched mineral bone density
when is a patient referred for a DEXA scan?
- low trauma fracture
- osteopenia/ vertebral fracture seen on XRAY
- steroid therapy
- early menopause
- secondary causes
- strong family history
what is FRAX?
a calculator to work out 10 year fracture possibility
what does FRAX consider?
T score Alcohol R.A glucocorticoids smoking previous fractured hip previous fracture afe BMI
what is the conservative management of osteoporosis?
weight bearing exercise
calcium rich diet
vitamin D supplements
avoid alcohol and smoking
what anti-resorptive medications is given for osteoporosis?
- oestrogen
– bisphosphonates (alendronate, risedronate, etidronate)
selective oestrogen receptor modulators
calcitonin
what bone forming agents can be given for osteoporosis?
- PTH (teriparatide fluoride)
anti rank ligand (denosumab)
what are CI to bisphosphonates?
oesophagitis
what is an alternative for bisphosphonates in osteoporosis?
strontium ranelate
what is the definition of osteomalacia?
- loss of bone mineralisation related to vitamin D deficiency
what is the different in bone amount in osteoporosis vs osteomalacia?
reduced in osteoporosis
normal in osteomalacia
what is the different in bone mineralisation in osteoporosis vs osteomalacia?
Normal is osteoporosis
reduced in osteomalacia
what are causes of osteomalacia?
- vitamin D deficiency
- lose of vit D through the gut
- defect in production of vit D
what can cause Vitamin D loss in the gut contributing to osteomalacia?
- coeliac disease
- pancreatic insufficiency
- cholestatic liver disease
- chapattis
what are causes of defective Vit D production?
- familial hypophosphaetaemic rickets
CKD
fanconis syndrome
what is the presentation of osteomalacia?
- bone pain
- proximal weakness
- malaise
- symptoms of hypocalcaemia
- deformity
- fractures
- rickets (hypotonia, growth retardation, skeletal deformities)
what blood results suggest osteomalacia?
- low calcium
- low phosphate
- low vit D
- raised PTH (due to low calcium)
- increased serum alkaline phosphatase
what can be seen in osteomalacia Xrays?
- normal or osteopenia
- looser zones
- pseudo fractures often in ribs, scapula, pubic rami and upper femur
what is seen in Xray of someone with rickets?
Cupping and fraying of metaphyses
widened epiphyseal plates
what is a definition of pagets disease of the bone?
- a condition of abnormal bone remodelling
what genes are involved with pagets disease?
5q35 QTER
what are the phases of pagets disease?
- lytic phase
- mixed phase
- sclerotic phase
what is the lytic phase of pagets?
intense osteoclastic resorption
what is the sclerotic phase of pagets disease?
osteoblast bone formation dominates
what is the presentation of pagets disease?
pain deformity osteoarthritis fractures neurological symptoms (deafness and conductive defects) sarcomatous transformation cardiac failure
what are differentials of raised alkaline phosphatase?
- metastatic bone disease
- osteomalacia
- pagets disease
- lliver disease
- hyperparathyroidism
what is seen on XRay in pagets?
marked areas of sclerotic and lytic lesions
what are complications of pagets disease?
- stress fractures
- increased OA
- skull enlargement can cause deafness, hydrocephalus
- high output cardiac failure
- osteosarcoma
what is osteopetrosis?
increased bone density due to decreased osteoclast action
what is the treatment of osteopetrosis?
bone marrow transplant
calcitriol
what is osteopoikilosis?
- spotted bone disease
- islands of deep cortical bone appear within the medullary cavity and the cancellous bone of the long bones
what is a bisphosphonate fracture?
An atypical femoral fracture is a diagnosis of exclusion:
- not spiral or comminuted
- not to the femoral neck or intertrochaneric
- no evidence of malignant bone tumour
- not periprosthetic
