EXAM 3 Bone and Joint

Question 1

osteomyelitis

Answer 1

infection of bone causing inflammation of bone marrow and surrounding bone

Question 2

septic arthritis

Answer 2

inflammatory reaction within joint tissue and fluid due to microorganism

Question 3

prosthetic joint infection

Answer 3

infection of a prosthetic joint and joint fluid

Question 4

Tissue and fluid cultures

Answer 4

osteomyelitis: bone sample/biopsy from surgery
Septic arthritis and prosthetic joint infections: joint aspiration and examination of synovial fluid

blood cultures are good

S. aureus

Question 5

Standard treatment duration

Answer 5

Standard treatment ranges from 2-8 weeks

Osteomyelitis: 4-8 weeks
Septic arthritis: 2-4 weeks
Prosthetic joint infection: 6-12 weeks

Question 6

osteomyelitis risk of infection

Answer 6

due to blood flow slowed significantly

Question 7

pathogenesis of bone and joint infections

Answer 7

Hematogenous spread: microbe reaches bone via blood stream

Contiguous spread: microbe reaches bone from SSTI or direct inoculation

Vascular insufficieny: microbe reaches bone from STI

Question 9

Osteomyelitis treatment

Answer 9

surgery

empiric ABX therapy:
Cefazolin
Ceftriaxione
Cefepime
Piperacillin/tazobactam Ampicillin/sulbactam
Meropenem
Levo/cipro
+ MRSA coverage as needed:
Vancomycin, daptomycin, linezolid

Question 10

oral ABX options for organism

Answer 10

streptococci - amoxicillin, cephalexin, clindamycin

mssa - dicloxacillin, cephalexin, cefadroxil, TMP/SMX, linezolid

MRSA - linezolid, TMP/SMX, clindamycin

GNRs - TMP/SMX, FQs

Question 11

Septic arthritis diagnostic criteria

Answer 11

Polymorphonuclear neutrophil count > 50,000

Radiolgic findings: X-ray, CT, MRI

Question 12

Septic arthritis treatment

Answer 12

Joint drainage and ABX therapy

Empiric ABX therapy like osteomyelitis based on organism

Question 13

septic arthritis treatment duration

Answer 13

S. aureus, GNR – 4 weeks

Streptococci – 2 weeks

N. gonotthoeae – 7 – 10 days

Question 14

prosthetic joint infection diagnostic criteria

Answer 14

Lab: WBC, ESR, CRP

Arthrocentesis to culture

Radiologic: X-ray

Question 15

Prosthetic joint infection treatment

Answer 15

surgical intervention:
debridement and retention of prosthesis
1-stage exchange
2-stage exchange
aputation with complete removal

Antibiotic therapy

Question 16

debridement and retention of prosthesis

Answer 16

pathogen-directed treatment + rifampin

oral antibiotic + rifampin

Question 17

1-stage exchange

Answer 17

pathogen-directed treatment + rifampin
oral anitbiotic treatment

Question 18

2-stage exchange

Answer 18

pathogen directed treatment

Question 19

amputation with complete removal

Answer 19

pathogen-directed treatment for 24-48 hours