Infection

Question 1

What is the name given to inflammation of bone and medullary cavity, usually located in one of the long bones?

Answer 1

Osteomyelitis

Question 2

In what ways can osteomyelitis be classified?

Answer 2

• Acute / chronic
• Contiguous /haematogeneous
• Host status eg. Sickle cell = more likely to get salmonella in bone

Question 3

Can osteomyelitis recur after treatment?

Answer 3

Yes

Question 4

What is contiguous spread?

Answer 4

Spread of infection to structures adjacent to where it started
e.g. in open fracture

Question 5

Who is most likely to get haematogenous osteomyelitis?

Answer 5

IVDUs
Prepubertal children
Central lines/ dialysis/ elderly

Question 6

What can predispose to osteomyelitis?

Answer 6

• Open fractures
• Diabetes/ Vascular insufficiency
• Prosthetic joint infection
• Specific hosts and pathogens

Question 7

What is the treatment for an open fracture?

Answer 7

aggressive debridement
fixation
soft tissue cover

Question 8

What is the difference between direct and indirect confirmations of infection?

Answer 8

Direct = sample

Indirect = scan

Question 9

Antibiotics can get into areas where pus collects TRUE/FALSE

Answer 9

FALSE

=> you have to debride the bone and THEN use antimicrobials

Question 10

What types of bacteria usually infect open fractures?

Answer 10

Staphylococcus aureus

aerobic gram negative bacteria

Question 11

How is osteomyelitis diagnosed in diabetes/vascular insufficiency?

Answer 11

Probe to bone (60% sens, 90% specific)

Question 12

What joints are commonly affected in ostoemyelitis in PWIDs?

Answer 12

Unusual sites 
Sternoclavicular Joint
Sternochondral Joint 
sacroiliac joint 
pubic symphysis

Question 13

What uncommon infections can be seen in haematogenous osteomyelitis of PWIDs?

Answer 13

Pseudomonas
Candida
Eikenella corrodens (needle lickers)
Mycobacterium tuberculosis

Question 14

What type of bacteria are most likely to infect dialysis patients?

Answer 14

Staphylococcus aureus (most common)
Aerobic gram negatives

Question 15

What is Osteitis pubis?

Answer 15

Urogynae procedures predispose to bacterial causes
Aseptic osteitis pubis
Triggered by surgery

Question 16

What are the risk factors for osteomyelitis in the clavicle?

Answer 16

Neck surgery

Subclavian vein catheterisation

Question 17

What do SAPH and CRMO stand for and in what age groups do they occur?

Answer 17

Synovitis Acne Pustolosis Hyperostosis Osteitis
- usually in ADULTS

Chronic Recurrent Multifocal Osteomyelitis
- usually in KIDS

Question 18

How do SAPHO and CRMO present on an X-Ray?

Answer 18

Lytic lesions

note these conditions are NOT osteomyelitis

Question 19

What type of abscess may predispose to vertebral osteomyelitis?

Answer 19

Epidural abscess

Psoas abscess

Question 20

What symptoms can be present if a patient is thought to have vertebral osteomyelitis?

Answer 20

fever
insidious pain 
tenderness
neurological signs/ symptoms
raised inflammatory markers

Question 21

How sensitive is the first vs the second biopsy when testing for osteomyelitis?

Answer 21

60-80% 1st biopsy
90% 2nd biopsy

If still no answer consider open biopsy

Question 22

Whilst waiting on a biopsy result from the lab, the patient must be given empirical antibiotics TRUE/FALSE?

Answer 22

FALSE
osteomyelitis = not a medical emergency
=> wait for lab results before antibiotics

Question 23

How is vertebral osteomyelitis treated?

Answer 23

Drain large paravertebral/ epidural abscesses

Antimicrobials for 6 weeks

Question 24

When would you repeat and MRI in vertebral osteomyelitis?

Answer 24

only if :

• Unexplained increase in inflammatory markers
• Increasing pain
• New anatomically related signs/ symptoms

Question 25

What factors increase the risk of prosthetic joint infection?

Answer 25

- Rheumatoid arthritis - Diabetes - Malnutrition - Obesity

Question 26

What is the difference between planktonic and sessile infection?

Answer 26

``` Planktonic = bacteraemia Sessile = biofilm grows slowly very close to prosthesis and allows bacteria to aggregate ```

Question 27

How is infection of a prosthetic joint usually treated?

Answer 27

Ideally removal of prosthesis and cement Therapy for at least 6 weeks Re-implantation of the joint after aggressive antibiotic therapy.

Question 28

What microbes are often responsible for infection of a prosthetic limb?

Answer 28

``` Gram + - staph aureus - Staph epidermidis - Propionibacterium acnes (upper limb prostheses) RARE: streptococcus/enterococcus ``` Gram - - E-coli - Pseudomonas aeruginosa (Also Fungi/mycobacteria sp.)

Question 29

How can infection spread to cause septic arthritis?

Answer 29

- from infectious focus in adjacent tissue (e.g. abscess) - from focus of osteomyelitis in adjacent bone - direct invasion from penetrating wound - haematogeneous spread

Question 30

What organisms are most likely to cause septic arthritis?

Answer 30

- Staphylococcus aureus - Streptococci - Coag neg staphylococci (prosthetic joints) - Neisseria gonorrheae (If sexually active)

Question 31

When is it okay to give patient empirical antibiotics?

Answer 31

When there is suspicious of SEPSIS

Question 32

What is polymyositis?

Answer 32

bacterial infection of the skeletal muscles which results in a pus-filled abscess

Question 33

What symptoms of tetanus make it a muscular disease?

Answer 33

Neurotoxin it releases causes spastic paralysis. Binds to inhibitory neurones => preventing release of neurotransmitters

Question 34

What treatment can be given in tetanus?

Answer 34

``` Surgical debridement. Antitoxin. Supportive measures Antibiotics (Penicillin / Metronidazole) Booster vaccination ```

Question 35

What microbes often cause myositis?

Answer 35

Viral – diffuse = HIV, Influenza, Rabies, Chikungunya etc Protozoa fungal