MSS5

Question 1

What are the different types of osteomyelitis?

Answer 1

Hematogenous (seeding from previous bacteremia)– common in children
Direct implantation ( resulting form penetrating injury
Contiguous: resulting from direct spread of bacteria from overlying wound (more common in adults)
Infection from prosthesis: resulting from infection of prostethic material implanted in bone (more common in adults)

Question 2

What are some common pathogens in: Hematogenous osteo?

Answer 2

S. aureus, Strep, gram negatives, TB, salmonella (sickle cell)

Question 3

What are some common pathogens in: Direct implantation osteo?

Answer 3

Psuedomonas aeruginosa

Question 4

What are some common pathogens in: continguous osteo?

Answer 4

S. aureus, gram negative, Strep, anaerobes, candida

Question 5

What are some common pathogens in: prosthetic joint osteo?

Answer 5

Coagulase negative staph, S.aureus, gram neg. Strep

Question 6

What are effective imaging techniques for osteo?

Answer 6

Bone scans, WBC scans or MRI

Question 7

Can you culture an open ulcer to determine source of contiguous osteo?

Answer 7

NO. unreliable

Question 8

Can you treat osteo without a biopsy?

Answer 8

Yes. Empiric tx

Question 9

What is a biofilm?

Answer 9

Biofilms are aggregations of microorganisms adherent to a surface. Frequently embedded in a matrix of slime or extracellular polymeric substance or glycocalyx

Question 10

How do you treat Osteomyelitis? Which antibiotic is useful in treating biofilm organisms?

Answer 10

long course of abx (usually 6 weeks of anti-biotics, additional PO drugs may be required. Surgery might be necessary to remove sequestra or prosthesis. Rifampin is useful in treating biofilm organisms.

Question 11

What are the 3 types of cartilage?

Answer 11

Hyaline, Elastic and Fibrocartilage

Question 12

What are the characteristics of hyaline cartilage. Where is it found?

Answer 12

Characterized by homogenous matrix with chondrocytes randomly distributed.
Looks: blue and glossy
Found in: nasal, costal, laryngeal, tracheal, bronchial, epiphysis

Question 13

What is articular cartilage?

Answer 13

Articular cartilage is a special type of hyaline cartilage that covers most articular surfaces. No perichondrium.

Question 14

What are the characteristics of elastic cartilage? Where is it found?

Answer 14

Characterized by chondrocytes that are randomly distributed in matrix.
Looks yellow d/t elastin
Found in: auricular, external auditory meatus, auditory, laryngeal, epiglottis

Question 15

What is fibrocartilage? Where is it found?

Answer 15

Characterized by ovid chondrocytes that are in parallel with collagen fibers. No perichondrium
Looks: white and opaque
Found in IVD, symphysis, articular disc, tendon insertions

Question 16

What makes up cartilage?

Answer 16

chondrocytes embedded in cartilage matrix

Question 17

what are the primary fiber types in cartilage?

Answer 17

Type II collagen

Question 18

What is the primary component of cartilage matrix?

Answer 18

Ground substance ( hydrated gel of water, ions and proteoglycans)

Question 19

What is a lacunae?

Answer 19

space in cartilage matrix that is occupied by chondrocytes

Question 20

How do chondrocytes develop?

Answer 20

chondrogenic cells have potential to become chondroblasts. When chondroblasts surrounds itself with cartilage matrix–> chondrocyte

Question 21

How does cartilage grow?

Answer 21

Interstitial growth: as chondrocyte divide, they separate d/t new matrix production ( growth of long bones)
Appositional growth: chondroblasts secrete cartilage matrix and become enclosed in it. New cartilage is added to surface of existing cartilage