Flashcards in Bone and Joint Infections Deck (40)
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1
Osteomyelitis
Infection of the bone
2
3 mechanisms of how bone infection may be brought about
Haematogenous- bacteria in the blood seed bone
Contiguous focus-spread from adjacent area of infection
Direct incoculation-trauma or surgery
3
Stage 1 of osteomyelitis and likely cause
Medullary-necrosis of medullary contents- haematogenous
4
Stage 2 of osteomyelitis
Superficial-necrosis limited to exposed surfaces
5
Cause of stage 2 superficial osteomyelitis
Contiguous- Diabetic foot ulcer, pressure sores
6
Complications of stage 3
Necrosis- no blood supply- can't treat with antibiotics. Surgery required to cure
7
Stage 3 osteomyelitis
Localised- full thickness cortical sequestation, stable before and after debridement
8
Stage 4 osteomyelitis
Diffuse- extensive, unstable bone
9
describe the pain with osteomyelitis
localised pain, not relieved with resting and progressive
10
Clinical presentation of osteomyelitis
Pain
Soft tissue swelling
Erythema
Warmth
Localised tenderness
Reduced movement of affected limb
Systemic upset uncommon (fever, chills, night sweats)
11
Most common causative organism of osteomyelitis (60%)
Staph A
12
6 main causative organisms of osteomyelitis
Staph A
Stretococci
Enterococci
Gram -ve bacilli
Anaerobes
M. TB
13
Gold standard diagnostic procedure for osteomyelitis
Cultures and histology of bone biopsy/needle aspirate
14
Name 4 diagnostic tests for osteomyelitis
Gold standard
Blood cultures
Superficial swabs
C-reactive protein
15
When would you give empirical antimicrobial therapy in osteomyelitis?
When signs of sepsis
16
Which 5 antibiotics have acceptable penetrance in bone?
Clindamycin
Ciprofloxacin
Vancomycin
Beta-Lactam
Gentamicin
17
What is the treatment of choice for Staph A. osteomyelitis
Flucloxacillin IV
18
How are antibiotics usually administered in osteomyelitis?
IV
19
Septic arthritis
Inflammatory reaction in joint space (arthritis) caused by infection, resulting from direct invasion of the joint
20
2 classifications of septic arthritis
Native (natural) joint infection
Prosthetic (artificial) joint infection
21
2 ways in which organisms enter the joint in native joint infection
Haematogenous or trauma
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How does synovial tissue facilitate 'seeding'?
Highly vascular and lacks a basement membrane
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Predisposing factors for native joint infection
RA
Trauma
IVDU
Immunosuppressive disease
24
Prognosis for native joint infection
Not fatal but severe lack of function if not treated
25
How do organisms enter the joint in prosthetic joint infections?
Haematogenous
During surgery or following wound infection after surgery
26
Why are prosthetic joints susceptible to infection?
Cement provides a surface for bacterial attachment
27
How does infection affect the joint in prosthetic infection?
Polymorph infiltration results in tissue damage instability of the prosthesis
28
How does infection affect the joint in native infection?
Cartilage erosion causes joint space narrowing/impaired function
29
Predisposing factors to prosthetic joint infection
Prior surgery at site
RB
Corticosteroid therapy
DM
Poor nutritional status
Obestiy
Age
30
