Infection of bones & joints

Question 1

causes of joint infection

Answer 1

usually bacteria

viruses eg rubella, mumps, hepatitis B = mild arthritis

Question 2

septic arthritis cause?

Answer 2

medical emergency
usually caused by staphylococcal or streptococcal bacteria, most common cause staph aureus
joints = infected by direct injury or blood

Question 3

risk factors septic arthritis

Answer 3

prosthetic joints
pre existing joint disease
recent intra articular steroid injection
DM

Question 4

clinical features septic arthritis

Answer 4

hot painful swollen red joint - acute

Question 5

management septic arthritis

Answer 5

joint aspiration and synovial fluid analysis, gram stain and culture, polarized light microscopy for crystals
Bloods FBC ESR CRP cultures
Swab of urethra, cervix & anorectum if gonococcal infection

Question 6

what will joint aspirate show if septic

Answer 6

opaque, contains up to 75,000 WCC/mm3 mainly neutrophils

(norm = straw coloured,

Question 7

what will joint aspirate show if inflammatory

Answer 7

cloudy, >3000 WCC/mm3

(norm = straw coloured,

Question 8

rx of non-gonococcal bacterial arthritis

Answer 8

• flucoxacillin & oral fusidic acid
• modify rx depending on culture & sensitivity
• adequate joint drainage by needle aspiration
• immobilise joint
• NSAIDs

Question 9

osteomyelitis

common cause

Answer 9

inflammation of bone or bone marrow, usually due to infection
due to metastatic haematogenous spread (eg a boil) or local infection
staph aureus

Question 10

symptoms osteomyelitis

Answer 10

fever
local pain
erythema
sinus formation in chronic

Question 11

diagnosis osteomyelitis

Answer 11

CT, MRI, bone scan

Question 12

rx osteomyelitis

Answer 12

flucoxacillin and fusidic acid (antibiotics)

Question 13

rx gonococcal arthritis

Answer 13

penicillin, ciprofloxacin or doxycycline for 2 weeks and joint rest

Question 14

rx meningococcal arthritis

Answer 14

penicillin