Test 2: 24: septic arthritis

Question 1

why is septic arthritis important

Answer 1

hyaline cartilage does not heal well- can lead to irreversible lameness and dysfunction

can lead to systemic infection

Question 2

what type of infections in septic arthritis in small animals

Answer 2

bacteria: staph, strep

Mycobacteria, mycoplasmal, fungal, protozoal

Question 3

what can causes septic arthritis

Answer 3

idiopathic
hematogenous
direct: trauma or surgery

Question 4

what history can lead to septic arthritis

Answer 4

recent surgery or penetrating injury at or around joint
soft tissue infection around joint
chronic OA- hematogenous spread

Question 5

PE of septic arthritis in small animal

Answer 5

lameness
effusion
very painful joint
warm at joint

Question 6

xray of septic arthritis will show

Answer 6

joint effusion (stifle- cranial displacement of fat pad)

soft tissue swelling

no osseous or degenerative abnormalities (although pre exisiting OA can lead to septic arthritis)

Question 7

ideal septic arthritis cytology will show

Answer 7

Highly suppurative inflammation with intracellular bacteria

high neutrophils, high cell count

Question 8

septic arthritis will have what type of cells on cytology

Answer 8

high cell count
low mononuclear cells

high neutrophils

normal joint: low cell count, high mono, low neutrophils

Question 9

negative culture from arthrocentesis, what does that mean

Answer 9

does NOT rule out septic arthritis

common to get negative results

Question 10

blood culture medium is used for

Answer 10

aerobic culture

Question 11

what types of test for septic arthritis

Answer 11

arthrocentesis- culture
CBC
Chem
look for other infections: skin, UTI, mouth ect.

Question 12

how to do arthrocentesis

Answer 12

sterile
specific site to avoid nerves and arteries
do not get greedy: stop suction before removing needle

do not want blood containmination

Question 13

normal arthrocentesis will

Answer 13

less then 0.5 ml
clear or light yellow
viscosity: 2.5 cm
turbidity: clear

Question 14

treatment of septic arthritis

Answer 14

antibiotics

lavage joint

Question 15

in cats — are the most common bacteria for septic arthritis

Answer 15

Pasteurella multocida and Bacteroides

Question 16

in dogs what is the most common bacteria to cause septic arthritis

Answer 16

staph
strep

Question 17

how long to use antibiotics in septic arthritis

Answer 17

2 weeks beyond resolution of clinical signs (4-6 weeks)

Question 18

prognosis of septic arthritis in small animals

Answer 18

variable

depends on duration, degree of ECM degradation, concurrent diseases

Question 19

less common cause of septic synovial structures in large animals

Answer 19

bacterial cellulitis around a joint can invade into the joint

Question 20

why are foals more likely to have hematogenous cause of septic arthritis

Answer 20

tortuous nutrient vessel at edge of growth plate can trap bacteria

weak immune system
umbilical cord is exposed to infection

Question 21

clinical signs of septic synovial structures in horse

Answer 21

severe NMB lameness
joint effusion
joint swelling
heat, pain on palpation

Question 22

3 types of septic arthritis in neonates/foals

Answer 22

S -Type: Synovial fluid and membrane infected
E-Type: Articular epiphysis involved
P-Type: Physis of long bone infected

Question 23

S-type septic arthritis in foal

Answer 23

Synovial fluid and membrane infected

Question 24

E-type septic arthritis in foals

Answer 24

Articular epiphysis involved

Question 25

P- type septic arthritis in foals

Answer 25

Physis of long bone infected

Question 26

what kind of bacteria for neonate/foal septic arthritis

Answer 26

**gram negative** **rhodoccus**: Can cause primary sepsis or immune-mediated arthritis (polyarthritis)

Question 27

what kind of bacteria for septic arthritis in adult horse

Answer 27

**Penetrating wound**: Gram negative > gram positive **Iatrogenic**: Gram + (staph or strep)

Question 28

history of neonates with septic arthritis

Answer 28

Partial or complete failure of passive transfer High sepsis score Concurrent infection: umbilical infection, pneumonia, GI inflammation **fever**

Question 29

history of adult horse with septic arthritis

Answer 29

no fever- normally, unlike foal history of wound, surgery hematogenous spread nearby infection- abscess or cellulitis

Question 30

synoviocentesis

Answer 30

aspirate away from open wound distend joint with sterile fluid to see if open/communicating with wound inject joint with antibiotics after sampling

Question 31

what is regional limb perfusion

Answer 31

place tourniquet- then give IV antibiotics to only that leg

Question 32

I f significant amount of fibrin or thick synovial fluid or boney lesion, more aggressive treatment is selected such as ---

Answer 32

arthroscopy: less invasive arthrotomy: common in farm animals

Question 33

treatment of septic arthritis in horse

Answer 33

joint lavage antibiotics: either IV or oral or regional limb perfusion