Bone and Joint Infection

Question 1

When the infection replaces marrow with improperly remodeled bone it is called?

Answer 1

Osteomyelitis (bone and marrow inflammation)

Question 2

What are the two classifications of osteomyelitis based on duration?

Answer 2

1-Acute

2-Chronic

Question 3

What are the 3 characteristics of Acute osteomyelitis?

Answer 3

1-Evolves over several days to weeks
2-Often appears more inflammatory
3-Can profess to chronic

Question 4

What are the 4 characteristics of chronic osteomyelitis?

Answer 4

1-Hallmark of having dead bone (sequestrum)
2-Involucrum (reactive bony encasement of sequestrum)
3-Sinus tract formation
4-Less inflammatory, local bone loss

Question 5

How do organisms in osteomyelitis replicate?( in what direction?)

Answer 5

the path of least resistance, usually toward bony endplate and into the joint causing septic arthritis or through a sinus tract

Question 6

What are the two modes of entry for a osteomyelitis?

Answer 6

1-Hematogenous (bacteremia such as in vertebral osteomyelitis)
2-Contiguous (trauma induced, compound fracture, surgery, etc)

Question 7

What 2 organisms are the most common cause of osteomyelitis?

Answer 7

1-Staphylococcus aureus (coagulase-positive)
2-Coagulase negative staphylococci (staph epidermis)

*less common streptococci, enterobacter, e. coli.

Question 8

What does polymicrobial mean?

Answer 8

multiple microbes, typically gram negative aerobes and anaerobes

Question 9

Almost always polymicrobial, what are common causes of osteomyelitis in diabetic foot?

Answer 9

1-Staph aureus and beta hemolytic streptococci
2-Gram negative bacilli such as enterobacter, pseudomonas aeruginosa
3-Anaerobes
4-Candida (rarely)

Question 10

What typically causes Vertebral osteomyelitis?

Answer 10

1-Staph aureus (most common)
2-e. coli
3-Coagulase-neg staph and propionibacterium
4-pseudomonas aeruginosa and candida
5-rarely tuberculosis

Question 11

What typically causes osteomyelitis of the jaw?

Answer 11

-Oral organisms such as strep viridian’s, anaerobes, actinomyces israelii(sulfur granules)

Question 12

Though most osteomyelitis treatments involve antibiotics as well as surgery, what principles should be kept in mind for antibiotics and surgery respectively?

Answer 12

• Antibiotic: adequate coverage, tissue penetration and long-term treatment
• Surgical: Debridement, remove hardware, manage dead space, complete wound closure

Question 13

How is arthralgia described?

Answer 13

• Not inflamed
• Painful
• Can ve viral or bacterial

Question 14

How is arthritis described?

Answer 14

• Inflamed
• rubor, calor, dolor, tumor
• may be bacterial

Question 15

How is septic arthritis caused?

Answer 15

Hematogenous from ongoing bacteremia, direct inoculation of contiguous spread

Question 16

When septic arthritis is polyarticular what is the likely cause?

Answer 16

Staph bacteremia

*Monoarticular would mean in one location

Question 17

What is typically of prosthetic joint infections?

Answer 17

• less likely to cause fever
• fewer inflammatory signs
• persistent worsening pain
• may have sinus tract
• often gram (-) cocci or coagulase neg staph