Septic Arthritis / Septic Physitis

Question 1

Broad causes of Septic Arthritis:
1
2
3

Answer 1

1. Naturally ocurring
2. Iatrogenic
3. Infectious (usually bact, but can be viral, mycobacterial, fungal)

Question 2

Two main ways Septic Arthritis can naturally occur?

Answer 2

Hematogenous or Traumatic

Question 3

Iatrogenic causes of Septic Arthritis?

Answer 3

During arthroscopy, arthrocentesis, fracture repair, etc

Question 4

Pathogenesis Steps of Septic Arthritis:
1.
2.
3.
4. Creates cycle of \_\_\_\_\_\_\_

Answer 4

1. Synovitis/capsulitis
2. fibrin deposition
3. Cellular infiltrates ie degraditive enzymes, cytokines
4. Creates cycle of cartilaginous matrix destruction

Question 5

The cycle of cartilaginous matrix destruction in Septic Arthritis leads to:

1. Decreased ___ synthesis
2. Loss of ____
3. ____ of the joint
4. (painful/not painful)?
5. Compromised ________

Answer 5

1. HA
2. PG
3. Effusion
4. Painful
5. synovial blood flow

Question 6

Risk factors for Septic Arthritis in Foals

1. Same as what other disease?
2. ______ –> risk of _____.

Answer 6

1. Foal septicemia

2. Failure of Passive Transfer —> risk of bacteremia. Leads to localization of bacteria and hematogenous spread.

Question 7

Types of septic arthritis in foals:
1.
2.
3.

Answer 7

1. S
2. E
3. P

Question 8

S-Type Septic Arthritis:

1. Affects what parts of joint?
2. Age affected?
3. More likely to affects joints that (smaller/larger)?
4. More likely to affect (single/multiple) joint(s)?
5. CxS: a) b) c)

Answer 8

1. Synovial membrane/fluid
2. < 1 week
3. Larger, ie stifle/tibiotarsal
4. Multiple
5. Acute, severe lameness, effusion.

Question 9

E-Type Septic Arthritis

1. Affects what parts of joint?
2. Rads will reveal ___-
3. Age affected?
4. Relevant History?
5. Affects (single/multiple joints?
6. Which bone(s) does it target?
7. Initial CxS?
8. Late CxS?

Answer 9

1. bones adjacent to articular cartilage, particularly the expanding epiphysis
2. Subchondral lysis
3. Weeks old
4. FPT, concurrent dz (pneumonia, diarrhea)
5. Multiple
6. Distal femur, talus, tibia, radius
7. Mild intermittent lameness
8. Acute exacerbation of lameness/effusion

Question 10

P-Type Septic Arthritis

1. Affects what part of bone?
2. Age affected?
3. Sites affected?
4. (single/multiple) sites affected?
5. Initial CxS?
6. Late CxS?
7. General CxS?

Answer 10

1. Physis of long bones
2. Weeks –> months
3. Distal physis of MCIII/MTIII, radius, tibia
4. ONE SINGLE SITE USUALLY
5. Premonitory lameness
6. Acute severe lameness/swelling
7. Perarticular swelling without effusion

Question 11

Diagnosis of P-Type Septic Arthritis

1.
2.
3. Possible ____
4. DO NOT _____. Why?

Answer 11

1. Radiographs
2. Aspirate of physis
3. Bone Biopsy
4. Debride: Will damage physis and can cause premature closure.

Question 12

Septic Arthritis - Foals:

1. __ and __ types are similar.
2. CxS: a) b) c) +/-
3. Synovial Fluid Analysis will reveal….
4. Bloodwork will reveal..
5. U/S will reveal ____

Answer 12

1. S-type, E-type
2. a) lameness, b) effusion, c) +/- fever
3. > 50,00 cell count, >90% neutrophils, color: normal to cloudy, red, organge, pink
4. Increased fibrinogen +/- leukocytosis.
5. Hypercellular fluid

Question 13

Septic Arthritis in Foals:

1. Be sure to identify…..
2. Be sure to U/S the ____
3. Prognosis for survival = ___%

Answer 13

1. ALL JOINTS INVOLVED
2. Umbilicus
3. 77%

Question 14

Septic Arthritis: Iatrogenic Risk Factors in Aduts:

1.
2.
3.
4. Usually what bacteria?

Answer 14

1. Synovial Surgery
2. Fracture repair
3. Arthrocentesis
4. Staphylococcus

Question 15

Septic Arthritis: Risk Factors in Adult

1. Most common bact that will be involved if traumatic cause?
2. Bacteremia is (common/rare) in adults?

Answer 15

1. Enterobacteriaceae (staph, pseudomonas, fungi)

2. rare

Question 16

T/F

You should treat an open joint as an infected joint.

Answer 16

T

Question 17

Septic Arthritis in Adults: CxS

1. Similar to foals without _____
2. (acute/chronic) onset of (mild/severe) lameness?
3. Other signs:
   a)
   b)
   c) +/- ____

Answer 17

1. bone involvement
2. acute severe lameness
   3.
   a) synovial effusion
   b) peri-articular heat and swelling
   c) +/- Fever

Question 18

Diagnosis of Septic Arthritis in Adults

1. Gold standard?
2. Gross exam to evaluate ___, ____ and ____.
3. ___/___
4. Clinpath: evaluate a) b) c)

Answer 18

1. Microbiology
2. color, clarity, viscosity
3. Clinical Signs/Hx
4. a) total protein
   b) Cell count/differential
   c) staining of smears

Question 19

Diagnosis of Septic Arthritis in Adult Horses

Culture and sensitivity:

1. Use what kinds of media? Why?
2. Can submit for ____ culture.
3. Do what if initial sample is negative?
4. Foals - Aspirate ___ if suspect physitis

Answer 19

1. Enrichment Media / Blood culture media. MUCH BETTER YIELD
2. Fungal
3. Repeat culture
4. Physis

Question 20

Septic Arthritis Cytology:

1. Color?
2. Clarity?
3. WBC count?
4. Cell differentials?
5. TP?

Answer 20

1. Serosanguinous, orange
2. Turbid
3. Thousands +
4. > 90% neuts, usually degenerated
5. > 3.5g/dL

Question 21

Septic Arthritis Diagnosis:

1. Most common isolate?
2. Culture (before/after) antibiotics?
3. Take tap (towards/away) from wound.
4. Why?

Answer 21

1. Staphylococcus
2. Before
3. AWAY
4. So if there’s a chance that it doesn’t get through to the joint yet you don’t want to inadvertently introduce the bacteria into the joint.

Question 22

Imaging of Septic Arthritis:

Radiographs will reveal
1.
2.
3.

Answer 22

1. Marked effusion
2. Soft tissue swelling
3. Osseous involvement

Question 23

Imaging of Septic Arthritis

benefits of ultrasound:
1.
2. Reveals what characteristic sign?
3. For foals?

Answer 23

1. Guides fluid aspirate (esp. in difficult structures
2. Hypercellular fluid
3. FOALS - check umbilicus

Question 24

For successful treatment of Septic Arthritis, you must have _______ and ________

Answer 24

Rapid recognition of disease
and
Immediate aggressive treatment

Question 25

Possible Consequences of Septic Arthritis: 1. 2. 3. 4. Complications: 1. 2.

Answer 25

1. Acute synovitis with supuurative effusion 2. Cartilage destruction via cellular and bacterial enzymes and cytokines 3. Capsular fibrosis/ankylosis 4. DJD 1. Contralateral Limb Laminitis 2. Euthanasia

Question 26

``` Treatment Goals of Septic Arthritis: 1. Return _______ to normal environment. Accomplished by doing what three things? a) b) c) ``` Can result in what if not accomplished: 2. 3.

Answer 26

1. Cartilage a) eradicate infection b) eliminate inflammation c) minimize matrix loss and cartilage damage 2. Irreversible structural damage and decreased prognosis for return to function 3. contralateral limb laminitis

Question 27

Treatment of Septic Arthritis after sample acquisition: 1. Begun treatment with what kind of drugs? Which ones specifically? 2. _____ is a mainstay of treatment. When? How much?

Answer 27

1. Broad spectrum antibiotics. Pencillin/gentamycin 2. LAVAGE! Early and often, and in large volumes (5-10 L)

Question 28

Lavage of Septic Arthritis: ``` 1. _____ lavage ideal. Benefits of this method: a)________ delivery b) Removal of _____ c) Allows ________ ``` 2. ______ method is also fine. a) Downside: Sometimes ______ b) Needle Size? c) Place needles in (infected compartment/all compartments)

Answer 28

1. Arthroscopic a) Rapid and accurrate delivery b) removal of fibrin clots c) targeted debridement 2. Needle (through and Through Lavage) a) frustrating b) large! 18-16G c) all compartments

Question 29

Lavage of Septic Arthritis: 1. Sedation and local anesthesia: Use what drug? 2. Use general anesthesia for what two procedures?

Answer 29

1. 2% Mepivacaine | 2. Arthroscopy and arthrotomy

Question 30

Lavage of Septic Arthritis: Lavage Solutions: Options: 1. _______s like ____ or _____ 2. DO NOT ADD _____ or ______. Why? a) b) 3. Can consider adding ___ instead, but it's not required

Answer 30

1. Balanced Electrolye Solution: ie LRS, Normosol 2. Chlorhexidine or Povidone-iodine a) Cytotoxic! Will cause inflam b) Doesn't work! It doesn't do anything beneficial! 3. DMSO

Question 31

Lavage of Septic Arthritis: 1.Lavage how often? ``` 2. Stop when there is resolution of : a) b) c) d) ```

Answer 31

1. Daily initially if not fully responsive 2) a) Lameness b) Effusion/swelling c) WITH D/C of NSAIDs, analgesics d) Synovial fluid SAA levels

Question 32

Treatment of Septic Arthritis: Antibiotics 1. Start with what drugs? 2. If it's iatrogenic? 3. T/F: Systemic Admin is vital to successful outcome.

Answer 32

1. Broad spectrum ie Pen/Gen. 2. 100% local treatment because results are as good or better vs systemic. Don't make that big of a difference. 3. F: Local is vital.

Question 33

When is it ok to stop admin of antibiotics in septic arthritis case?

Answer 33

**Minimum 30 days and 2 weeks beyond resolution of CxS**

Question 34

Treatment of Septic Arthritis: Local Antibiotics: 1. Admin Methods: a) b) c) d) 2. CRI vs Intermittent bolus determined by ____ 3. Sensitive to what drug? Why use it?

Answer 34

1. a) Intra-articular b) RLP c) IO d) Antibody impregnated biomaterials 2. C/S 3. Aminoglycosides. MIC is very high, most bacteria cannot survive.

Question 35

Intra-articular admin of antibiotics: 1. Instill when? 2. Benefit of this method of admin? 3. 500 mg Amikacin provides ___hr concentration > MIC for most pathogens. 4. Be cautious of : a) b)

Answer 35

1. After completion of lavage 2. Very high conc of drugs at site of sepsis, 10-100x systemic admin 3. 72 hr 4. a) using in multiple joints. b) exceeding daily systemic dose.

Question 36

Regional Limb Perfusion: 1. Performed how often? 2. Technique: a) Proper _____ placement is essential. Describe it. b) catheter size? c) Inject (slowly/quickly)? d) Apply ____ topically

Answer 36

1. QOD 2. a) tourniquet. Above and below if possible, using Esmarch tourniquet. After injection, leave on for 30 min b) 25-27 G c) Slowly, over 5-10 min d) Surpass

Question 37

Regional Limb Perfusion - Dosage General Rule of Thumb: 1. ____ of systemic dose 2. For distal limb? 3. For above carpus/tarsus? 4. Cattle: Admin method? Benefit? 5. Caution:

Answer 37

1. 1/3rd 2. qs to 30 mL 3. qs to 60 mL 4. RLP with Florfenicol. High tissue conc effective against F. necrophorum and A. pyogenes 5. DO NOT EXCEED TOTAL DAILY SYSTEMIC DOSE

Question 38

IO antibiotic administration: 1. before injection: a) b) c) d) 2. Inject (slowly/quickly)? 3. Leave tourniquet for how long?

Answer 38

1. a) Sedation/local anesthetic b) Drill 4 mm hole c) Male end of luer tip extension set fits d) Apply esmarch tourniquet 2. Slowly 3. 30 min

Question 39

Septic Arthritis: Analgesia 1. (is/is not) reccomended? Why/Why not? ``` 2. Options: a) b) c) d) Hindlimbs: e) ```

Answer 39

1. Is, because it's extremely painful and will be accompanied by contralateral limb laminitis. Also they will spend excessive time recumbent which can result in decubital ulcers, resp dz, or weight loss. 2. a) NSAIDs - be sure to monitor for toxicity though. b) Opiates c) CRI - lidocaine or ketamine d) Epidural catheter with opiates or detomidine e) GI protectants like omeprazole AND sucralfate

Question 40

1. What is the most reliable and important measure to asses response to tx of septic arthritis? 2. Beware false positive response from..... 3. Avoid confusion how?

Answer 40

1. Clinical lameness and pain 2. NSAIDs and other analgesics 3. By never d/c any antibiotic or lavage until horse is evaluated AFTER analgesics have been reduced or d/c.

Question 41

Adjunct Treatment of Septic Arthritis: IA ___, ___, ____ are all reasonable, but which is most plausible.

Answer 41

HA, ACS, PRP. HA.