osteomalacia/myelitis + pagets

Question 1

haematogenous osteomyelitis

Answer 1

results from bacteraemia
- usually monomicrobial
- commonest form in kids

vertebral osteomyelitis is commonest form

Question 2

risk factors for haematogenous osteomyelitis

Answer 2

sickle cell anaemia
IV drug user
immunosuppression - medication, HIV, infective endocarditis

Question 3

non-haematogenous osteomyelitis

Answer 3

from contiguous spread of infection from adjacent soft tissues to bone/direct injury to bone
- often polymicrobial
- commonest form in adults

Question 4

risk factors for non-haematogenous osteomyelitis

Answer 4

diabetic foot ulcers/pressure sores
diabetes
peripheral arterial disease

Question 5

commonest causative organism in osteomyelitis

Answer 5

Staph aureus

!!! except in sickle cell anaemia –> salmonella

Question 6

osteomyelitis investigations

Answer 6

MRI

Question 7

osteomyelitis management

Answer 7

flucloxacillin for 6weeks

clindamycin is pen allergic

Question 8

osteomalacia

Answer 8

describes softening of the bones secondary to low vit D levels that in turn lead to decreased bone mineral content

• in kids = rickets
• in adults = osteomalacia

Question 9

causes of osteomalacia

Answer 9

vit d deficiency - malabsorption, lack of sunlight, diet

chronic kidney disease
drug induced - anticonvulsants
rickets
liver diaese - cirrhosis
coeliac disease

Question 10

osteomalacia presentation

Answer 10

bone pain
bone/muscle tenderness
fractures - femoral neck

proximal myopathy - may lead to a waddling gait

Question 11

osteomalacia investiagtions

Answer 11

bloods
- low vit D
- low calcium, phosphatw
- raised ALP

xray - translucent bands (Loosers zones or pseudofractures)

Question 12

osteomalacia management

Answer 12

vit D supplementation (loading dose initially)

calcium sup - if dietary calcium inadequate

Question 13

Pagets disease of the bone

Answer 13

increased but uncontrolled bone turnover

Question 14

pagets pathophys

Answer 14

excessive osteoclastic resorption followed by increased osteoblastic activity

Question 15

commonest bones affected in pagets

Answer 15

skull
spine/pelvis
long bones of lower extremities

Question 16

pagets predisposing factors

Answer 16

increasing age
male sex
northern latitude
family history

Question 17

pagets presentation

Answer 17

older male with bone pain + isolated raised ALP

untreated sx = bowing of tibia, bossing of skull

(only 5% symptomatic)

Question 18

pagets investigations

Answer 18

bloods
- raised ALP
- (calcium + phosphate normal)

xrays
- early - osteolysis
- later - mixed lytic/sclerotic lesions
- skull = thickened vault, osteoporosis circumscripta (thick skull but thin in middle)

bone scintigraphy
- increased uptake focally at sites of active bone lesions

Question 19

markers of bone turnover

Answer 19

• procollagen type I N-terminal propeptide (PINP)
• serum C-telopeptide (CTx)
• urinary N-telopeptide (NTx)
• urinary hydroxyproline

Question 20

indications for Pagets management

Answer 20

bone pain
skull or long bone deformity
fracture
periarticular pagets

Question 21

management of pagets

Answer 21

bisphosphonate
- oral risedronate
- IV zoledronate

Question 22

pagets complications

Answer 22

deafness -> cranial nerve entrapment

bone sarcoma
fractures
skull thickening
high output cardiac failure