5.9 K) Orthopaedics Septic Arthritis

Front 1

Broad classifications / categories for septic arthritis risk factors ? (3)

Back 1

1. Direct penetration
2. Joint disease
3. Host Immune Deficit

Front 2

Direct penetration risk factors for septic arthritis

Back 2

1. Trauma
2. Medical / Surgical [ arthrocentesis ]
3. IV drug use

Front 3

Host Immune Deficit risk factors for septic

arthritis

Back 3

1. Glucocorticoid / immunosuppressive

therapy
2. HIV
3. Chronic illness [ Diabetes ]
4. Cancer

Front 4

Which of the statements is incorrect regarding septic arthritis?
1. The majority of cases are in children and young adults
2. It occurs most commonly via haematogenous seeding.
3. It ultimates, untreated, in synovial abscess formation and cartilage necrosis
4. A polyarticular presentation is more common in Staphylococcal

infection
5. The elderly can present non-specifically, with lethargy, fever and

vomiting.

Back 4

4. Polyarticular Septic arthritis = Gonococcal

Front 5

Typical findings of synovial fluid analysis in septic arthritis:
1. Colour
2. Turbidity
3. Leukocytes
4. Predominant cell

Back 5

1. Colour : yellow-green
2. Turbidity : purulent
3. Leukocytes : > 50,000-100,000 u/L
4. Predominant cell: Polymorphonuclear

leukocyte [PMN] { > 50%}

Front 6

Other than Staphylococcus aureus, list the age specific bacteria for septic arthritis:

1. Children
2. Young Adults
3. Older Adults

Back 6

1. Children :
a. Group A Streptococcus {GAS} = Streptococcus Pyogenes

[ * Group B = neonates ]
b. Haemophilus influenzae
2. Young Adults:
a. Neisseria gonorrhoeae
3. Older Adults:
b. Gram negative species [ Pseudomonas ; Enterobacteriaceae ]
c. Group A Streptococci {GAS} = Streptococcus Pyogenes

Front 7

which is incorrect regarding Septic arthritis?
1. Gonococcal and paediatric infections have a generally good

response, with low rates of joint morbidity
2. 2000-50,000 leukocytes U/L in the joint aspirate is more typical for

non-septic / inflammatory arthritis
3. All regimens of antibiotic treatment must include antistaphylococcal cover
4. Gram negative cover [ ceftriaxone ] is used as Clinically indicated
5. Polyarticular sepsis in rheumatoid arthritis has a good response to

intensive antibiotic therapy.

Back 7

5. Polyarticular Sepsis in Rheumatoid

Arthritis :

mortality rates 15%
major morbidity 50%

Front 8

Mechanisms for septic arthritis [5]

Back 8

1. Haematogenous **
2. Spread from contiguous source of infection
3. Direct implantation
4. Postoperative contamination
5. Trauma

Front 9

Non infectious differential diagnosis for acute monarticular arthritis?

Back 9

1. Crystal-induced arthritis
2. Fracture
3. Haemarthrosis
4. Foreign body
5. Osteoarthritis
6. Monarticular rheumatoid arthritis
7. Osteomyelitis

Front 10

Link the bacterium for septic arthritis and the age group most likely :

1. Adolescents A. E coli
2. Sickle cell patients B. Pseudomonas
3. Post Operative C. Salmonella
4. Neonates D. N. gonorrhoeae
5. Children E. Group B strep.

Back 10

1. D.
2. C.
3. B.
4. E.
5. A.

Front 11

What is the most common organism causing septic arthritis?

Back 11

Neisseria gonorrhoeae.

Front 12

What infection am I ?

Female, pregnant, with fever, chills and

migratory polyarthralgias. I may have

tenosynovitis , as well as a dermatitis.I have a rash on the extremities and trunk, which has small macules and papules with necrotic

centres.

Back 12

Disseminated gonococcal infection.

Front 13

In regards to septic arthritis, which is incorrect? 1. Gram stain is positive 60-80% cases

2. Culture is positive 50% cases

3. Cell count is typically > 50,000 u/L

4. There is usually a predominance of PMN [>50-70%]

5. Gram positive organisms are the aetiology 60% of cases

Back 13

5. Gram Positive organisms : 80% cases

{Staphylococcus ; B Haemolytic Streptococci

[ GAS / GBS ] ; Streptococcus pneumoniae }

20 % cases Gram negative
[ E coli ; Haemophilus influenzae ]

Front 14

4 main causes of acute monoarthritis in the ED

Back 14

1. Gout
2. Septic arthritis
3. Reactive Arthritis [ post viral ; Reiter's]
4. Acute exacerbation of pre-existing

inflammatory arthritis