Infectious disease Flashcards
What type of salter Harris fracture is above the growth plate
2
What type of salter Harris fracture is below the growth plate
3
What type pf salter Harris fracture is through the growth plate
4
What type of salter Harris fracture causes the erasure of the growth plate (compression of it)
5
What type of salter Harris fracture is the separation of the growth plate
1
What is the most sensitive test for osteomyelitis
MRI
Which gender is more likely to get pediatric osteomyelitis
Boys (2x more)
What is the reason otherwise healthy kids will get osteomyelitis
Function of rich blood supply and an immature immune system
What is pediatric osteomyelitis often mistaken for
malignancy
What is the most common area in the body that children will get osteomyelitis
Femur and tibia
What pathogen is generally the cause of pediatric osteomyelitis
S. Aureus
What is the cause of osteomyelitis in sickle cell patients?
Salmonella
What is the most common reason neonates typically get osteomyelitis
Group B strep
What is the typical presentation in pediatric osteomyelitis
Febrile
Chills
Malaise
Localized pain/swelling
Unable to bear weight
What are acute phase reactants
ESR and CRP
What will be seen in a CBC with diff if a child has osteomyelitis
> 70% PMNs
How long does a child have to have osteomyelitis before changes are seen on X-ray
1-3 weeks
What is seen with chronic cases of pediatric osteomyelitis
Sequestrum and involcrum
What test should always be done for infections
biopsy
What test should always be done with tumors
Culture
When should a biopsy and culture be done in regards to antibiotics
Before starting treatment
What empiric treatment is used for non-surgical cases of pediatric osteomyelitis
Nafcillin or Oxacillin (Targeted antibiotics)
What is given for pediatric osteomyelitis with suspected MRSA
Clindamycin or vancomycin
How long is osteomyelitis generally treated for
4-6 weeks
How is pediatric osteomyelitis generally treated when surgery is required
Irrigation and debridement
Antibiotic impregnated cement beads
IV antibiotics x6 weeks
What do you watch the ESR and CRP for while treating pediatric osteomyelitis
A downward trend (CRP in 48-72 hrs) to know that the treatment is working
How do you confirm the resolution of an osteomyelitis infection
Culture after treatment has been given
What is the most common bacteria for adult osteomyelitis and where is the most common site of infection
S. Aureus
Vertebrae
How is adult osteomyelitis classified
by duration of symptoms
How long does acute osteomyelitis last in adults
Days to weeks after inoculation
How long does subacute osteomyelitis last in adults
weeks to months
How long does chronic osteomyelitis last in adults
months+ with reoccuance
What are the difference mechanisms of infection for adult osteomyelitis
Direct inoculation/contiguous spread
Sequela from vascular disease
neuropathy
hematogenous spread
If someone get osteomyelitis via surgery or trauma, what type of spread in this
direct inoculation / contiguous spread
If someone gets osteomyelitis from ulcers or is seen in LE, what is the mechanism of infection
Sequela via vascular disease
neuropathy
If someone get osteomyelitis via a UTI, endocarditis, dialysis.. what type of spread is this
Hematogenous spread
Where is osteomyelitis generally seen in adults
lower extremity
What is a chronic presentation of osteomyelitis in adults
fever, variable pain, purulence/abcess, open wound
Ability to probe to the bone on any wound or sinus tract
What is the gold standard for diagnosing adult osteomyelitis
Culture and biopsy
If someone is unable to mount an immune response to osteomyelitis, what tests will NOT be helpful
No increase in WBC
ESR/CRP unhelpful
Abscess in absent
What is the most common treatment for osteomyelitis in adults
Surgery
When is osteomyelitis non-surgical
Pt. unable to tolerate surgery
When in the spine
What are nonsurgical treatment options for adult osteomyelitis
IV antibiotics
Chronic suppressive antibiotics
When is a hyperbaric tank used in adult osteomyelitis
When it is refractory
How is adult osteomyelitis treated surgically
I&D (Generally multiple)
Closed wound vac
Target IV antibiotics
Amputation if unable;e to salvage
What type of joint is septic arthritis seen in
native joints
Who is septic arthritis more common in
Children
Where is septic arthritis seen in kids
hip or knee (More often the hip)
Where is septic arthritis seen in adults most commonly
Knee
If septic arthritis is seen in the SC joint- what is it indicative of
IVDU
Which kids are at higher risk for septic arthritis
Premie (Immature immune system)
C-Section
NICU babies
h/o Invasive procedures (Usually NICU babies)
If septic arthritis is from contiguous spread, what is it caused from
Osteomyelitis
How do adults most commonly get septic arthritis
Hematogenous spread (immune compromised)
Direct inoculation (Trauma that penetrates the joint capsule)
How to kids generally get septic arthritis
Hematogenous spread
What organism causes septic arthritis in children
Most common: Staph aureus or strep
Kingella Kingae
What causes septic arthritis is sexually active adults
Gonoccocal (Neisseria gonorrhoeae)
What is the cause of septic arthritis in IVDU patients
Gram negative bacilli (E.coli, Klebsiella, enterobacter)
What is usually the cause of septic arthritis in sickle cell patients
Strep pneumo or salmonella (Encapsulated organism-gut bacteria)
What organism causes septic arthritis after shoulder surgery
P. acnes
What is generally the cause of septic arthritis in animal bites
Pasturella multocidia
What is the cause of septic arthritis after the human bites
Eikenella corrodens
What is a typical presentation of septic arthritis
Acute joint pain
Joint effusion
Erythema
Warm to touch
Inability to bear weight
What is the typical presentation of septic arthritis in children
Hip resting in FABER position
Refusal to move extremity
What is the FABER position
Flexion
ABduction
External Rotation
What is the gold standard to diagnose septic arthritis
Arthrocentesis
What are the differential diagnosis’s that need to be ruled out for septic arthritis
Lyme (PCR)
Gout (Crystal analysis)
What needs to be tested with an arthrocentesis
Cell count with diff
Culture (Aerobic, anaerobic, AFB, Fungal)
Synovial fluid glucose
What is an AFB and what does it test for
Acid fast
Tests for mycobacterium which is an infectant for TB
What can you see on an X-ray OF a pediatric patient with septic arthritis
Joint space widening
What will ultrasound show in someone with septic arthritis
Can demonstrate effusion but will not show if there’s infection or not
What does MRI show with septic arthritis
Will show joint effusion and possible adjacent osteomyelitis in both adults and peds
What is typical treatment for septic arthritis
Washout (Arthroscopic vs open)
Empiric antibiotics
What antibiotics are used to treat septic arthritis
Vancomycin to cover staph +/- ceftriaxone
Ceftriaxone alone to cover neisseria gonorrhea
What is the only reason a washout would not be done for septic arthritis
If its gonococcal because that can be handled non-operatively
What are the complications associated with septic arthritis
Progression to osteomyelitis
End stage arthritis
When is the prognosis of septic arthritis bad in children
Age< 6months
Osteomyelitis already present
Delay > 4days till presentation
What is transient synovitis
Self limited inflammation of the synovium
Where is transient synovitis typically seen
the hip
What is transient synovitis preceded by
URI
What is the treatment for transient synovitis
Analgesics
activity modification will resolved
What is the most common tick borne illness in the US
Lyme arthritis
Where is Lyme an endemic
Midwest and northeast
What is the causative agent of Lyme arthritis
Borriela Burgdorferi
When is early Lyme disease present
1-30 days post infection (Erythema migrans)
When is acute disseminated Lyme infection present
weeks to months post infection
When is late Lyme disease present
Months to years after infection
If a patient presents with Mono or oligoarthritis, intermittent, self limiting joint effusion, warmth to the touch, and joint pain… what is the likely diagnosis
Lyme arthritis
What is the presentation for Lyme arthritis
+/_ hx of EM/ tick bites
No systemic symptoms
Mono or oligoarthritis
Intermittent,self limiting joint effusion
Warmth to the touch
+/- joint pain
How would you work up someone with Lyme arthritis
Elevated ESR/CRP
Positive Lyme serology
Arthrocentesis
Confirmatory synovial Lyme PCR
What might you see in a positive Lyme serology
IgM antibiodies if early
IgG antibodies if late
How would you treat septic arthritis
28days oral antibiotics
If symptoms persist, switch to IV antibiotics or a second round
What are the antibiotics you could use to treat Lyme arthritis
Doxycycline (Most common)
Amoxicillin
Cefuroxime
ceftriaxone
What is a serious complication for a total joint arthroplasty
Periprosthetic joint infection
Does a primary or a secondary total joint arthroplasty have a higher infection risk
Secondary
what is the most common pathogen that causes periprosthetic joint infections
S. Aureus
If you get a negative culture with a suspected joint infection, do you rule out the possibility of an infection?
No.. some bacteria has long incubation periods
If a patient presents with drainage from a joint more than 2 weeks post op, what do you suspect
Periprosthetic joint infection
If a patient presents with drainage from their joint, red/swollen/tender joint post surgery, chronic pain, decreasing ROM what are you suspicious of
Periprosthetic joint infection
What would you see in a CBC with diff in a preiprosthetic joint infection
Lower WBC levels
What is the treatment for an acute infection of a TJA
Washout and poly exchange
Targeted IV antibiotics (6weeks)
If a patient has a chronic TJA infection what is the treatment
Removal of implants
Diret antibiotic inoculation
Target IV antibiotics
If there was a failure to clear a PJI what is the treatment
Chronic suppressive oral antibiotics
Local wound care
Resection W/O re-implanation
Amputation
What is a girdlestone
Resection without preimplantation
What is the pre-procedure prophylaxis for a TJA
Amoxicillin
Clindamycin
Why do you retain hardware regardless of infection if a fracture is less than 6 weeks old
Because it is more important to keep joint stability
Which types of TJA have the highest failure rates
Intermedullary nails and open fracture
