Septic Arthritis Flashcards
true or false: septic arthritis is usually bacterial
true
what should you always check in foals with septic arthritis?
US umbilicus
palpate ALL joints to see which are involved
normal synovial fluid:
- appearance
- WBC count
- diff neutrophil count
- TP
normal:
- appearance: clear, pale yellow
- WBC <500 cells/dL
- diff <10% neutrophils
- TP <2 g/dL
risk factors for septic arthritis in foals
failure of passive transport
normal = >800
partial failure = 400-800
failure = <400
signs associated with P type septic arthritis in foals
periarticular swelling usually WITHOUT joint distension or effusion
diagnosing septic arthritis (3)
- microbiology (send in blood culture media)
- gross exam of synovial fluid
- clin path of synovial fluid (cell count, TP, smear)
treatment for septic arthritis
-Lavage MOST IMPORTANT: early + often + big volumes (5-10 L) until signs are gone
-arthroscopic is best because can debride but
requires GA
-needle through and through method: not as
targeted but can be done standing. Requires
LARGE needle (14, 16, or 18 G)
-use balanced electrolyte solution (LRS, normosol,
plasmalyte) +/- DMSO
-saline is last resort
-DO NOT use antiseptics (not effective + cytotoxic)
-broad spectrum antibiotics if needed (penicillin, gentamycin)
what might you see on US for septic arthritis?
hypercellular joint fluid
***also always check umbilicus for foals
G.S. for diagnosing septic arthritis
microbiology (send in blood culture media; good idea to also send for fungal; repeat a second time if first time is negative; ideally culture BEFORE antibiotics/treatment)
staph is most common
E type septic arthritis in foals:
- what does it affect?
- age?
- number of joints involved?
- epyphysis/bony involvement (rads show subcondral lysis)
- weeks old
- usually multiple joints involved
normal fibrinogen in horses? what level might you see with septic arthritis if bone involved?
normal: <400 mg/dL
if bone involved often >900 mg/dL
diagnosis of septic arthritis in foals (5)
-rads
-BW:
-fibrinogen usually >900 mg/dL when bone is
involved (normal is <400)
-+/- leukocytosis
-US: hypercellular fluid
-***always also check umbilicus
-synovial fluid aspirate (aspirate physis if p type):
-cell count >50,000
-neutrophils >90%
-color: normal to cloudy/red/orange/pink
-palpate ALL joints to see which are involved
most common organism cultured during septic arthritis cases
staph
types of septic arthritis in foals
- S type (affects synovial membrane and fluid)
- E type (epiphysis/bone involved)
- P type (physis involved)
complications of septic arthritis
- contralateral limb laminitis
- DJD
- ankylosis
- euthanasia
E type septic arthritis in foals:
- signs?
- most commonly affected sites?
- number of joints usually involved?
- signs: rads show subcondral lysis, history of FPT or disease, MILD lameness THEN acute exacerbation of lameness/effusion
- distal femur, talus, tibia, radius
- usually multiple joints involved
septic arthritis secondary to trauma is most commonly _____ in origin
enterobacter
also can be staph, pseudomonas, fungal
what important things to remember about lavaging septic joints? what two methods can you use?
-Lavage MOST IMPORTANT: early + often + big volumes (5-10 L) until signs are gone
-arthroscopic is best because can debride but
requires GA
-needle through and through method: not as
targeted but can be done standing. Requires
LARGE needle (14, 16, or 18 G)
-use balanced electrolyte solution (LRS, normosol,
plasmalyte) +/- DMSO
-saline is last resort
-DO NOT use antiseptics (not effective + cytotoxic)
septic arthritis secondary to arthrocentesis is usually ______ in origin
staph
S type septic arthritis:
- most common joints involved?
- number of joints usually involved?
- C.S.?
- signs: acute SEVERE lameness, effusion
- usually multiple joints involved
- common sites: usually larger joints (stifle, tibiotarsal)
causes of septic arthritis in horses
- trauma (usually enterobacter; also staph, pseudomonas, fungal)
- hematogenous (usually only foals)
- iatrogenic (usually staph)
P type septic arthritis in foals:
- age?
- common sites?
- number of sites common?
- age: older (weeks to months)
- number of sites: usually one physis
- common sites: distal physis of MCIII/MTIII, radius, tibia
difference in presentation between S type and E type of septic arthritis in foals
S type: SEVERE lameness; usually no bone involvement; just synovial membrane and fluid; usually <1 week
E type: bone involved, usually MILD lameness THEN acute exacerbation of lameness/effusion; usually weeks old with history of FPT or disease
both usually involve multiple joints
what size needle do you need to lavage septic joints using needle through and through method?
14, 16, or 18 G
S type septic arthritis in foals:
- what does it affect?
- age?
- number of joints involved?
- affects synovial membrane and fluid;
- usually < 1 week old
- usually multiple joints involved
true or false: you should NEVER debride a physis
TRUE
abnormal synovial fluid parameters:
- appearance
- WBC count
- diff neutrophil count
- TP
- turbid, serosanguinous
- WBC: thousands +
- > 90% neutrophils
- > 3.5 g/dL
