27 Infections of bone

Question 1

Prosthetic joint septic arthritis

What are definitions of these procedures?

Excision arthroplasty

DAIR

1 stage revision

2 stage revision

Answer 1

Excision arthroplasty - removal of prosthetic joint, and give antibiotics. Patient too unwell/ frail to re-implant

DAIR - debridement/ antibiotics/ implant retention.

1 stage revision - removal and re-implantation at same surgery

2 stage revision - removal of implant, then wait two weeks, then insert new implant

Question 2

Prosthetic joint septic arthritis.

Options for management -
DAIR
1 stage revision
2 stage revision
medical therapy only

Which patients are suitable for each of these options?

Answer 2

prostheses inserted <4 weeks ago -

• DAIR - if good bone stock/ soft tissue
• removal - if poor soft tissue, resistant organism

prostheses inserted >4 weeks ago -
- 1 stage revision - if good bone stock/ soft tissue, oral agents available

• 2 stage revision- if poor soft tissue, resistant organism
• medical therapy only - if high co-morbidities

Question 3

What is duration of antibiotic therapy for these treatment options?

DAIR hip/ shoulder

DAIR knee

Answer 3

• DAIR hip/ shoulder -
  6 weeks IV
  then further 12 weeks oral
• DAIR knee -
  6 weeks IV
  then further 26 weeks oral

Question 4

What is duration of antibiotic therapy for these treatment options?

1 stage exchange

Answer 4

• 1 stage exchange -
  6 weeks IV
  then further 12 weeks oral hip
  then further 12 week oral knee

may consider longer term suppression following this

Question 5

What is duration of antibiotic therapy for these treatment options?

2 stage exchange

Answer 5

• 2 stage exchange -

6 weeks IV

then 14 days antibiotic free before re-implantation

at surgery, take further samples for culture, and restart antibiotics

If cultures negative, can stop antibiotics

Question 6

CUH guidelines

Acute osteomyelitis

What are treatment options?

Answer 6

• co-amoxiclav IV
• vancomycin + ciprofloxacin - penicillin allergy
• vancomycin + tazocin - if hospital acquired

duration 4-6 weeks
minimum 2 weeks IV

Question 7

CUH guidelines

Vertebral infection

What are treatment options?

Answer 7

• vancomycin + tazocin
• vancomycin + ciprofloxacin - penicillin allergy

6 weeks IV
maybe further antibiotics for 2-6 weeks oral, depending on recovery

Question 8

CUH guidelines

septic arthritis - native

What are treatment options?

Answer 8

• co-amoxiclav
• vancomycin + ciprofloxacin - penicillin allergy

duration 4-6 weeks total
time to switch to oral depends on clinical response

Question 9

CUH guidelines

prosthetic joint infection

What are treatment options?

Answer 9

• vancomycin + tazocin

1 stage exchange
6 weeks IV
surgery
12 weeks oral hip/ 26 weeks oral knee

2 stage exchange
6 weeks IV
stop abx 2 weeks
surgery - take biopsies
restart antibiotics - stop if culture negative

Question 10

Traumatic open fracture

How are they classified?

Answer 10

Gustilo classification based on degree of skin and soft tissue damage, and damage to muscle bone

graded I/ II/ III

higher grade associated with higher rates of contamination e.g grade III 50% wound infection rate

Question 11

What is utility of ESR and CRP when trying to diagnose osteomyelitis?

Answer 11

ESR >60 and CRP >8 has sensitivity of 74% and specificity of 56% in diagnosing osteomyelitis. These results would make likelihood of osteomyelitis high

If ESR <30 - likelihood of osteomyelitis is low

If very high ESR and very high CRP, this may more likely reflect SSTI