Bone and Joint Infections

Question 1

what is the source of infection in acute septic arthritis?

Answer 1

> eruption of bone abscess
direct invasion (arthroscopy, penetrating wound, intra-articular injury)
haematogenous spread

Question 2

what organisms cause acute septic arthritis?

Answer 2

> E.coli
staph. aureus
strep. pyogenes
h. influenza

Question 3

describe the pathology of acute septic arthritis

Answer 3

> acute synovitis and purulent joint effusion
articular cartilage attacked by bacterial toxin and cellular enzyme
complete destruction of articular cartilage which then recovers, fibrosis creating bony ankylosis or leads to osteoarthritis

Question 4

how does acute septic arthritis present in a neonate?

Answer 4

> irritability
resistant to movement
very ill

Question 5

how doe acute septic arthritis present in a child or adult?

Answer 5

> acute pain in a single large joint
> reluctant to move
> increased temperature and pulse
> tenderness
> often involves superficial joints in adults

Question 6

what investigations would you carry out in acute septic arthritis?

Answer 6

> FBC
> WBC
> ESR
> CRP
> ultrasound
> blood cultures
> aspiration

Question 7

a child presents with an acute painful swollen knee and is reluctant to move it. they have an increased temperature and pulse and they are very tender.
give a differential diagnosis

Answer 7

> ACUTE SEPTIC ARTHRITIS
> trauma
> acute osteomyelitis
> irritable joint
> haemophilia
> rheumatic fever
> gout
> Gaucher's disease

Question 8

how is acute septic arthritis managed?

Answer 8

> general supportive measures
antibiotics 4/6 weeks
surgical drainage and lavage

Question 9

what could the source of infection for acute osteomyelitis be in neonates?

Answer 9

infected umbilical cord

Question 10

what could the source of infection for acute osteomyelitis be in adults?

Answer 10

> arterial line

> UTI

Question 11

what could the source of infection for acute osteomyelitis be in children?

Answer 11

> tonsils
boils
skin

Question 12

what organisms cause acute osteomyelitis in infants?

Answer 12

> E. coli
group B streptococci
staph aureus

Question 13

what organisms cause acute osteomyelitis in older children?

Answer 13

> staph aureus
strep. pyogenes
h. influenza

Question 14

what organisms cause acute osteomyelitis in adults?

Answer 14

> staph aureus

> pseudomonas aeruginosa

Question 15

what organisms cause acute osteomyelitis in a prosthetic?

Answer 15

> coagulase negative staphylococcus

> Propionibacterium

Question 16

what can cause acute osteomyelitis in HIV?

Answer 16

candidiasis

Question 17

what can cause acute osteomyelitis in sickle cell?

Answer 17

salmonella

Question 18

what is the pathology in acute osteomyelitis?

Answer 18

there is acute inflammation causing suppuration and release of pressure.
there is then necrosis of the bone (sequestrum) then new bone formation.
this then resolves or goes onto a complications

Question 19

how does acute osteomyelitis present in an infant?

Answer 19

> failure to thrive
> range of movement
> drowsy
> metaphyseal tenderness and swelling
> positional changes
> common in knee

Question 20

how does acute osteomyelitis present in a child?

Answer 20

> severe pain
> not weight bearing
> swinging fever
> maliase
> tachycardia
> toxaemia

Question 21

how does acute osteomyelitis present in an adult?

Answer 21

Primary: thoracolumbar spine, back ache

secondary is more common

Question 22

what investigations should be carried out in acute osteomyelitis?

Answer 22

> US
> MRI
> aspiration 
> isotope bone scan
> labelled WCC
> x-ray
> microbiology (bone biopsy, tissue swabs)

Question 23

what is the differential diagnosis in acute osteomyelitis?

Answer 23

> acute septic arthritis
acute inflammatory arthritis
transient synovitis
trauma
soft tissue infection (TSS, gas gangrene, necrotising fasciitis, cellulitis)
(> sickle cell, Gaucher’s disease, haemophilia, rheumatic fever)

Question 24

how is acute osteomyelitis managed?

Answer 24

> supportive (pain and dehydration)
> rest
> splintage
> antibiotics 4-6weeks
> surgery: drainage and lavage

Question 25

what are the indications surgery is needed in acute osteomyelitis management?

Answer 25

> aspiration of pus
> abscess drainage
> debriment of dead/infected tissue
> infected joint replacement
> non-operative not working

Question 26

what are the complications acute osteomyelitis?

Answer 26

> septic arthritis
> altered bone growth
> chronic osteomyelitis
> pathological fracture
> metastatic infection
> septicaemia

Question 27

what sources of infection are there in chronic osteomyelitis?

Answer 27

> operation
open fracture
diabetes

Question 28

what organisms are involved in chronic osteomyelitis?

Answer 28

> strep. pyogenes
staph aureus
proteus
e. coli

Question 29

what treatment is there for chronic osteomyelitis?

Answer 29

> surgery to eradicate the bone infection
> amputation
> correct deformity
> treat any soft tissue problem
> long term antibiotics?

Question 30

what complications can arise form chronic osteomyelitis?

Answer 30

> squamous cell carcinoma
chronically discharging sinus and flare ups
ongoing metastatic infection
pathological fracture

Question 31

how does a TB bone/joint infection present?

Answer 31

> ill health
> pain
> swelling
> loss of weight
> low grade pyrexia
> decreased range of movement
> ankylosis
> deformity

Question 32

how is TB bone/joint infection diagnosed?

Answer 32

> marked thickening of the synovium
> marked muscle wasting
> periarticular osteoporosis
> x-ray
> joint aspiration and biopsy
> Mantoux test
> sputum/urine collection

Question 33

what is the differential diagnosis in a TB joint/bone infection?

Answer 33

> haemorrhagic arthritis
> tumour
> pyogenic arthritis
> monoarticular RA
> transient synovitis

Question 34

how is TB infection in the joint/bone managed?

Answer 34

> rest
> splinting
> chemotherapy
 - rifampicin, ethambutol, isoniazid 8 weeks
 - rifampicin, isoniazid 6-12 months