Osteomyelitis

Question 1

what causative organism in common to acute osteomyelitis at all ages

Answer 1

staph aureus

Question 2

2 common sources of infection in adults

Answer 2

UTI and aterial line

Question 3

3 common sources of infection in children

Answer 3

boils, skin abrasions and tonsilitis

Question 4

1 common source of infection in infants (<1y/o)

Answer 4

infected umbilical cord

Question 5

2 modes of infection spread in osteomyelitis

Answer 5

haematogenous and local (contiguous)

Question 6

what age groups is haematogenous spread most common

Answer 6

children and the elderly

Question 7

3 examples of contiguous causes of acute osteomyelitis

Answer 7

cellulitis, open fracture and surgery

Question 8

infection from candida is most common in what immune disease

Answer 8

HIV AIDS

Question 9

what occupation are likely to be infected by mycobacterium marinium?

Answer 9

fishermen

Question 10

common organism in IVDA

Answer 10

pseudomonas aeruginosa

Question 11

causative organsim of tonsilitis which will cause acute osteomyelitis in children

Answer 11

strep. pyogenes

Question 12

which part of a long bone is usually the site of infection

Answer 12

metaphysis

Question 13

two commonly infected joints

Answer 13

hip and and radial head

Question 14

what is a sequestrum

Answer 14

a piece of dead bone

Question 15

what is a involucrum

Answer 15

new bone growth outside the existing bone, in this case, outside dead bone

Question 16

progression of infection and resolution in acute osteomyelitis

Answer 16

in medullary cavity/haversian in cortex –> acute inflammation –> increased pressure –> vascular stasis –> necrosis leading to a sequestrum –> pressure releases into joint –> blood returns to bone –> new bone growth can occur

Question 17

presentation of acute osteomyelitis in infants under a year

Answer 17

failure to thrive
generally ill, drowsy and irritable
decreased range of movement
tenderness and swelling of bone

Question 18

most common site of acute osteomyelitis in infants

Answer 18

knee

Question 19

presentation of acute osteomyelitis in children

Answer 19

severe pain
holding neighbouring joints in flexed position
not weight bearing
fever
tachycardia
malaise, nausea and vomiting

Question 20

most common site of primary acute osteomyelitis in adults

Answer 20

thoracolumbar spine

Question 21

what is Pott’s Disease?

Answer 21

vertebral osteomyelitis from haematogenous spread of tuberculosis

Question 22

presentation of primary acute osteomyelitis in adults

Answer 22

backache
elderly, diabetic or immunocompromised
history of UTI

Question 23

presentation of secondary acute osteomyelitis in adults

Answer 23

severe pain
fever
swelling, red, tender bone
pain on movement
Hx of open fracture or surgery

Question 24

what neuro symptom would you expect in someone who has bone infection secondary to diabetes

Answer 24

neuropathy

Question 25

bloods in acute osteomyelitis

Answer 25

FBC, neutrophils, ESR and CRP

Question 26

when do changes become visible on X-ray

Answer 26

after about 2 weeks, necrosis and involucrum

Question 27

Scans you can do for osteomyelitis

Answer 27

``` x-ray ultrasound mri isotope scan with gallium or technetium labelled WBC scan with indium ```

Question 28

how do isotope scans works

Answer 28

show up at infected sites

Question 29

how many blood cultures do you need to do in haematogenous infection

Answer 29

3

Question 30

microbiology

Answer 30

blood cultures bone biopsy swabs or biospy from surrounding site (up to 5)

Question 31

5 differential diagnoses

Answer 31

cellulitis, erysipelas, acute septic arthritis, acute inflammatory arthritis and necrotising fasciitis

Question 32

conservative treaments for acute

Answer 32

analgesia, fluids, rest and splint

Question 33

how long does antibiotic regimen last in acute osteomyelitis

Answer 33

4-6 weeks

Question 34

how long does antibiotic regiemen last in chronic osteomyelitis

Answer 34

3-6 months

Question 35

indications for surgery in acute

Answer 35

drainage pus for diagnosis drain abscess debridement

Question 36

antibiotic regimen in acute

Answer 36

flucloxacillin for 6 weeks (or clindamycin if penicillin allergic) +/- fusidic acid or rifampicin for first 2 weeks. IV then oral after 2 weeks when they've stabilised and inflammatory markers go down

Question 37

mortality from acute osteomyelitis before antibiotics

Answer 37

70%

Question 38

5 complications of acute osteomyelitis

Answer 38

``` septicaemia metastatic infection pathological fracture septic arthritis chronic osteomyelitis ```

Question 39

true/false - the same organism is usually the cause of flare-ups in chronic osteomyelitis

Answer 39

true

Question 40

pattern of progression in chronic osteomyeltis

Answer 40

repeated flare-ups of breakdown of 'healed' wounds

Question 41

appearance of chronic osteomyelitis on histology

Answer 41

chronic inflammation

Question 42

malignant complication of chronic osteomyelitis

Answer 42

squamous cell carcinoma (0.07%)

Question 43

true/false - is it appropraite in chronic osteomyelitis to wait for culture and sensitivity results before commencing antibiotic treatment

Answer 43

true - unless severe and imminently life threatning, will reduce resistance and improve outcomes

Question 44

treatment for chronic osteomyelitis

Answer 44

``` surgical debridement IV antibiotic for 6 weeks gentamicin cement deformity correction and reconstruction amputation ```