Bone and Joint infections

Question 1

How does septic arthritis present?

Answer 1

Hot swollen painful joint

Erythema, tenderness, reduced ROM

Question 2

Investigation and treatment steps for septic arthritis?

Answer 2

1. Aspiration – gram staining, crystal microscopy, culture and antibiotic sensitivities
2. Emperical Antibiotics - Flucloxacillin + rifampicin
3. Blood cultures
4. MRI
5. Workup for sepsis / severity
6. Repeat aspiration/ Washout

Question 3

Question 4

Native joint Septic arthritis most commonly affect which joints?

Answer 4

Knee > Hip > shoulder

Question 5

Native joint Septic arthritis usally occurs due to? (2)

Answer 5

Haematogenous and/or Iatrogenic

Question 6

List 4 causitive organisms in native joint septic arthritis

Answer 6

1. Staphylococcus aureus incl MRSA
2. Streptococci
3. Gram negatives in Immune deficiency, urinary or intestinal invasive procedures, elderly people, renal failure, chronic joint disorders and diabetes
4. Gonococci , Borrelia ( Lyme ) & TB

Question 7

First line emperical antibiotics for gram positive bacteria?

Answer 7

Flucloxacillin + Benzylpenicillin

Question 8

First line emperical antibiotics if there is an MRSA risk?

Answer 8

Vancomycin/ Teicoplanin

Question 9

Duration of antibiotic treatment in native joint spetic arthritis

Answer 9

Upto 6 weeks from last positive culture

2-3 weeks IV followed by oral

Question 10

What is the first thing we MUST do if we suspect a Prosthetic Joint Infection?

Answer 10

ALWAYS SEEK ORTHOPAEDIC OPINION

Question 11

What defines an ‘early’ Prosthetic Joint Infection?

Answer 11

< 30 days

Question 12

List 4 causitive organisms in Prosthetic Joint Infections

Answer 12

1. Staphylococcus aureus including MRSA
2. Coagulase negative staphylococci
3. Streptococci
4. Gram negatives – enterobacteriaceae

+ Other gram positives… it is rarely fungal

Question 13

List 3 management steps for prosthetic joint infections?

Answer 13

DAIR

Debridement, Antibiotics, Implant Retention (one vs two stage revision)

Question 14

What does DAIR stand for in management of prosthetic joint infections?

Answer 14

Debridement, Antibiotics, and Implant Retention

Question 15

Compare 2 stage vs 1 stage revision in the management of prosthetic joint infections

Answer 15

Two stage revision : Removal of the prosthesis, then delayed reimplantation, typically 6-8 weeks later

One stage revision : Removal of the prosthesis, then immediate reimplantation of a new prosthesis

Question 16

Emerical antibiotic treatment for PJI?

Answer 16

Vancomycin or Teicoplanin + Tazocin/meropenem

Question 17

Following cultures what other antibiotic may be used?

Answer 17

Rifampicin if organism is susceptible

Question 18

Duration of antibiotic treatment for PJI?

Answer 18

IV antibiotics for 6 weeks followed by oral antibiotics

Oral antibiotics 6 weeks - 4 _1/2 months

Answer 19

Question 20

Acute osteomyelitis is usually aquired via what route

cjeck?

Answer 20

haematogenous

Question 21

Subacute osteomyelitis is known as what?

Answer 21

Brodie’s abscess

Question 22

Compare the onset and characteristics of acute vs chronic osteomyelitis

Answer 22

Acute: typically presents 2 weeks after bone infection, characterised by inflammatory bone changes

Chronic: typically presents 6+ weeks after bone infection, characterised by the presence of bone destruction and formation of sequestra

Question 24

Question 25

How do we diagnose oteomyelitis? (4)

Answer 25

1. Blood cultures 2. Sinus track cultures/superficial ulcer swabs (usually do not correlate with cultures obtained at bone biopsy) 3. Bone biopsy for histology and culture 4. Imaging

Question 26

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Question 31

Question 32

What principals must we address for use of Antibiotics in osteomyelitis?

Answer 32

* Depends on risk factors * Gram positive cover essential * If not septic wait to get samples

Question 33

Duriation of antibiotic treatment for osteomyelitis?

Answer 33

Usually 6 weeks IV antibiotics followed by 6 weeks oral antibiotics

Question 34

Surgical management of osteomyelitis?

Answer 34

Drainage of abscess / debridement Spinal instability : fixation Amputation in context of diabetic foot infections

Question 35

What is OPAT?

Answer 35

Out-patient Parenteral Antibiotic Therapy ## Footnote Service to manage patients with severe non-life threatening infections requiring parenteral antibiotics in an ambulatory setting. Aims to reduce length of stay for complex infections or avoid admissions in other simpler infections

Question 36

List 3 benefits of OPAT

Answer 36

1. Home treatment - patients can recover in familiar surroundings 2. Hospital beds and nursing time gained 3. Indirect benefits - cost savings ## Footnote e.g. income to the acute trust from further admissions into the bed vacated through the use of OPAT, reduced cancellations of operations, improvements in efficiency of bed use and patient flow