Microbiology

Question 1

Three anatomical locations of infection in MSK

Answer 1

Bone, Joint + synovial, Muscle Infections

Question 2

Do what before treating bone

Answer 2

take sample

Question 3

how to treat septic patients

Answer 3

empirically

Question 4

Osteomyelitis

Answer 4

Inflammation of bone and medullary cavity (usually long bone). Acute/chronic, contiguous/haematogenous. May recur after treatment.

Question 5

Treatment of osteomyelitis

Answer 5

debridement and ABs

Question 6

Diagnosis of osteomyelitis

Answer 6

History > Bone Biopsy (gold standard) > Treat with ABs (await microbiology 2 days)

Question 7

Loves colonising prosthetic materials

Answer 7

Staph epidermidis

Question 8

Treat staph aureus with

Answer 8

flucloxacillin

Question 9

treat staph epidermidis with

Answer 9

vancomycin

Question 10

Dealing with Open fractures

Answer 10

Early management (aggresive debridement, fixation and soft tissue cover). Staph aureus + aerobic gram -ve bacteria.

Question 11

Diabetes/ Venous Insufficiency

Answer 11

Ofetn polymicrobial. Probe to bone to diagnose. Treat with debreidement and ABs

Question 12

Haematogenous Osteomyelitis

Answer 12

USually prepubertal children, PWIDs, Central lines/ dialysis/ elderly. Treatment is surgical. History > Bone Biopsy (gold standard) > treat with ABs (await dagnosis)

Question 13

Bacteria associated with Dialysis

Answer 13

staph aureus

Question 14

Osteitis Pubis

Answer 14

triggered by surgery, athletes can get it

Question 15

Clavicle Osteomyelitis

Answer 15

3% of osteo, risk factors of neck surgery and subclavian vein catheterisation

Question 16

Sickle Cell Osteo

Answer 16

Infarction of bone. STaph Aureus + Salmonella

Question 17

Gaucher’s Disease

Answer 17

Staph Aureus

Question 18

Vertebral Osteomyelitis

Answer 18

Mostly haemotegenous: PWID, IV sites, GU infections, SSTI, Post Op. CT guided bone biopsy. 90% have insidious pain, 90% raised inflammatory markers, MRI needed to be sure.

Question 19

Treatment of vertebral osteomyelitis

Answer 19

Drainage of large paravertebral/ epidural abscesses. ABs fro 6 weeks.

Question 20

Prosthetic Joint Infection risk factors

Answer 20

Rheumatoid arthritis, diabetes, malnutrition, obesity

Question 21

Prosthetic joint infection presentation

Answer 21

early = within month (haematoma/ wound sepsis)
late = >month (contamination at time of operation)

Question 22

Prostehetic joint infection diagnosis + treatment

Answer 22

Staph aureus (fluclox) Staph epidermis (Vancomycin). Treat by removing prosthesis, re-implantation following aggressive AB therapy.

Question 23

Septic Arthritis

Answer 23

Inflammation of joint space by infection. Direct invasion through wound, haematogenous spread, cellulitis, abscess, spread from osteomyelitis

Question 24

Septic arthtritis bacteria

Answer 24

Staph aureus, Streptococci, coag -ve staph (prosthesis), neisseria gonorrheae (sexually active)

Question 25

Septic Arthritis Diagnosis

Answer 25

Classic inflammation > microscopy of joint fluid > blood culture (if pyrexial) > exclude crystals

Question 26

Septic arthritis treatment

Answer 26

presume flucloxacillin (add ceftriaxone if <5 yrs)

Question 27

Pyomyositis

Answer 27

Infection of muscle. 90% staph, requires debridement.

Question 28

Tetanus

Answer 28

Clostridium tetani, gm +ve anaerobic rods. Spores (in gardens, soil e.g. soldie in trenches). Binds to inhibitory neurones, preventing release of neurotransmitters. Muscles spasms can impinge breathing so high level of care.

Question 29

Tetanus treatment

Answer 29

Surgical debridement, antitoxin, supportive, ABs (penicillin/ metronidazole, controversial as it is a toxin not bacteria)