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Flashcards in Osteomyelitis Deck (101):
1

What is osteomyelitis?

inflammation of bone and medullary cavity, usually located in one of the long bones

2

What is the treatment for osteomyeltisi?

debridement and antimicrobials

3

what type of infection is an open fracture?

contiguous infection

4

What are the symptoms of infection of an open fracture?

non-union and poor wound healing

5

What organisms are implicated in open frcature infections?

staph. aureus; aerobic gram negatve bacteria

6

What causes osteomyelitis with diabetic/venous ulceration?

contiginous infection

7

How is the depth of the infection in an infected ulcer?

probe to the bone

8

What is the rule of 2?

if the ulcer has been there for 2 months and >2 months then check for osteomyelitis and if can see tendon or bone

9

What are the indications for an x-ray with an ulcer?

if the ulcer is:
-chronic, indolent or deep
-there is a +ve probe-to-bone test
-increased levels of inflam markers

10

What is required to diagnose definitive osteo?

bone biospy for histology and culture

11

What should be avoided with antibiotic therapy in osteomyelitis?

empirical therapy- a biospy should always be done

12

When should empirical therapy be give?

if have sepsis or skin and soft tissue involvement

13

What empirical therapy would be given?

flucloxacillin

14

Who is haematogenous osteomyelitis seen in?

prepubertal children; PWID; central lines/ dialysis/ eldery

15

What bug is the infecting microbe if someone steps on a nail typically?

pseudomonas

16

What are the main organisms seen with PWIDs?

staph; strep

17

What are the main pathogens seen in dialysis patients?

staph aureus; aerbic gram negatives

18

What should you do if a patient with an IV has a positivie blood culture?

remove the IV line and repeat cultures until negative

19

What should be done if a patient has persistent positive blood cultures?

an echo

20

What predisposes to osteitis pubis?

urogynae procedures

21

What are the risk factors for clavicle osteo?

neck surgery and subclavian vein catheterisation

22

What pathogens are seen with sickle cell osteo?

salmonella and staph. aureus

23

Where is is sickle cell osteo seen in the body?

long bones

24

What is gauchers disease?

lysosomal storage disorder

25

What is SAPHO?

synovitis acne pustulosis hyperostosis osteitis

26

What is CRMO?

chronic recurrent multifocal osteomyelitis

27

What is the difference between SAPHO and CRMO?

SAPHO is seen in adults whereas CRMO is seen with children

28

What are SAPHO and CRMO?

osteomyeltiis like lesions-mulitfocal osteitis which is self-limited

29

How is osteo myeltiis excluded in SAPHO and CRMO?

history plus cultures

30

What is seen on investigations with SAPHO and CRMO?

raised inflam markers and lytic lesions on x-ray

31

What is the presentation of SAPHO and CRMO?

fever, weight loss, maliase, 5 or so active lesions in strange places- chest wall, pelvis

32

What might vertebral osteomyelitis be associated with?

epidural or psoas abscess; PWID; IV site infections; GU infections:SSTI; post-op

33

What are the features of vertebral osteomyelitis?

fever; insidious pain and tenderness; neurogloical signs; raised inflam markers; raised WBCs

34

What is the treatment for vertebral osteo?

draingae of large paravertebral/epidural abscesses; antimicrobials for 6 weeks

35

Why would an MRI be repeated in vertebral ostea?

unexplained increase in inflam marker; increasing pain; new anatomically related signs/symptoms

36

What is vertebral TB also known as?

Pott's disease

37

What is seen in patients with vertebral TB?

often NO systemic symptoms; half have skin and soft tissue infections and less than half have pulmonary TB

38

What should always be offered for in adults with skeletal TB?

HIV test

39

What should be checked in kids with vertebral TB?

reduced receptors for IFN-gamma; R1 etc

40

What are the risk factors for a prosthetic joint infection?

RA; diabetes; malnutrition; obesity

41

What are the mechanisms for infection of a prosthetic joint?

direct inoculation at time of surgery
manipulation of joint at time of surgery
seedingb of joint at a later time

42

What causes an early infection in prosthetic joints?

wound sepsis/haematoma- within one month

43

What causes a late infection in prosthetic joints?

contamination at the time of operation

44

Whhat local infections does S. aureus cause?

impetigo; funuculosis; cavitating pneumonia; osteomyelitis; septic arthritis

45

What systemic infections does staph. aureus cause?

bacteraemia; metastatic abscess; endocarditis; line-related sepsis

46

What toxin mediated diseases can staph. aureus cause?

acute gastroenteritis; toxic shock syndrome; scalded skin syndrom

47

What is PVL?

a toxin called panton-valentine-leukocidin that kills WBCs

48

What are the symtpoms of having a PVL producing Staph, aureus

skin infections; necrotising pneumonia; invasive infections eg bacteraemia, septic arthritis

49

What is a planktonic bacteria?

one that causes bacteraemia

50

What is sessile bacteria?

when planktonic bacteria undergo phenotypic transformation and form a biofilm with an ECM

51

How is infection of prosthetic joints diagnosed?

from mltiple cultures of perioperative tissue

52

What is the treatment for an infection of prosthetci joints?

removal of prosthesis and cement and antibiotic therapy fro at least 6 weeks and then re-implantation of the joint

53

What are the main pathogens that can cause infections of prosthetics?

staph. aureus, staph, epidermidis mainly

54

What is the significanve of prosthetic material with coagulase negative staph (staph. epi)

they have a low virulence and can only cause infection if prosthetic material is presnet

55

What is needed to treat PVL infection?

fluclox and an anti-toxin antibiotic- clindamycin or linezolid

56

what is the side effecto f clindamycin?

C. diff infections

57

What is the sie effevt of linexolid?

bone marrow failure

58

What antibiotic is used t/o treat cog negative staph?

vancomycin

59

What is the virulence factor in staph. epi?

slime which allows it to bind to plastic and form biofilms

60

How can septic arthritis occur?

haematogenous spread; direct invasion through a penetrating wound; spread from infectious focus (cellulitis, abscess) in adjacent soft tissues; spread from focus of osteomyelitis in adjacent bone

61

What is septic arthritis?

inflammation of the joint space caused by infection

62

What organisms cause septic arthritis?

staph. aureus; strep; coag neg staph. - prosthetic joints; neisseria gonorrhae- sexually active; haemophilus0 pre-school

63

What is the clinical presentation of septic arthritis?

sever pain, red, hot swollen plus limited movement, fever (if haematogenous)

64

What are the empirical antibiotics given for septci arthritis?

fluclox; ceftriaxone- in under 5s

65

What viruses can cause viral arthritis?

hep B; rubella; parvovirus; alphavirus

66

what is pyomyositis?

pussy muscle

67

What causes pyomyositis?

90% are staphylococcal but it depends on the site

68

How is pyomyositis treated?

wide debridement- removal of the infected muscles

69

What causes tetanus?

clostridium tetani

70

What is clostridium tetani?

gram positive strictly anaerobic rods- drumstick shapes

71

Where are tetenus spores found?

soil; gardens etc

72

How does tetanus cause illness?

the organism itself isnt invasive, illness is caused by a neurotoxin

73

What does tetanus do?

causes spastic paralyiss by binding to inhibitory neurones, preventing release of neurotransmitters

74

What is the incubation period for tetanus?

4 days to several weeks

75

what causes lock jaw with tetanus?

muscles spasming

76

What kills you with tetanus?

go into resp arrest as resp msucles are in spasm

77

What is the treatment for tetanus?

surgical debridement; antitoxin; supportive measures; antibtiocs; booster vaccination- toxoid

78

What is myositis?

viruses; protozoa; fungal infections

79

What is a myositis caused by protozoa associated with?

eosinophilia

80

What happens to the bone in osteomyelitis?

exudation of pus lifts up the periosetum interrupting blood supply to underlying bone and necrotic fragments of bone may form (sequestration. New bone formation created by the elevated periosteum forms an involcrum. Pus may dischanrge into joint spaces or via sinuses to the skin

81

What are the radiographic changes associated with osteomyelitis?

haziness+/- loss of density of afffectedf bone, then subperiostal reaction, and later, sequestrum and involcrum

82

What has reduced the prevalence of haemophilus influenzae osteo in children?

vaccine

83

what are sequestra?

infected dead bone

84

What are the signs of bone TB?

local pain, swelling, cold abscess formation +/- joint effusion; pain on movement and muscle wasting- if includes joint; wt lossl malaise; fever; lethargy

85

Who typically gets osteo in their feet?

diabetics

86

Who typically gets osteo in their vertebra?

IVDU

87

What types of bone tends to get infected in children?

vascular bone - long bone metaphyses

88

What are the signs of infection?

rubor; calor; dolor; tumour; functio laesa

89

What is important in the treatment of bone and joint infection?

dont start antibiotics until you know what youre treating

90

What does the technetium scan show?

osteoblast activity

91

What is the most common cause of acute osteomyelitis?

post-trauma/ open fractures

92

What causes acute osteomyelitis in children and immunosuppresssed?

haematogenous spread

93

What is the most common organism in acute osteomyelitis?

staph. aureus

94

What bug causes acute osteomyelitis in children?

haemophilus influenzae

95

What causes haematogenous osteomyelitis?

there is a clot in the blood vessel of the bone- which acts like an agar plate fro bacteria. blood flow in bone is already slow, if there is trauma this can damage the vessel wall- virchows triad

96

What imaging is used in diagnosing chronic osteomyelitis?

x-rays and MRI

97

What bugs should be covered in cellulitis?

staph and strep- fluclox and benzylpenicillin

98

What can be felt on palpation with necrotising fasciitis?

bubble wrap- organisms produce gas

99

What suggests an infected arthroplasty in the history?

if there has been poor wound healing and if the joint has always been painful

100

How are prosthetic infectiosn prevented during surgery?

clean air theatre; local antibiotics; systemic antibiotics; and a reduced duration of surgery

101

Which bugs infect prosthetics?

staph aureus and staph. epi (coag neg staph CNS)