Septic Arthritis in Children
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Transcript Septic Arthritis in Children
Septic Arthritis in Children
Hayan Hamameh
Orthopaedic surgery resident
Departmet of Orthopaedic Surgery
Teshreen Military Hospital
Suppervised by :
Hussam Aldin Sulaiman
Chief of Spine and Orthopaedic surgery department
Overview
1-Backgraound
fungi
Bacteria
+++
viruses
pyogenic A.
suppurative A.
purulent A.
pyarthrosis
Joint infection
Overview
1-Backgraound
challenging clinical problem because:
(1) signs and symptoms may be subtle and overlap with
those found in other conditions.
(2) diagnosis methods are relatively insensitive.
(3) optimal management, including duration of
antibiotics and surgical approach, is not evidence based.
Overview
2-Etiology
Normal joints
synovial fluid
synovial membrane
highly vascular
no basement membrane
EASY entry of bacteria
Overview
2-Etiology
Bacteria deposition in S. membrane acute
inflammatory cell response.
no basement plate bacteria may access to the S. fluid.
bacterial endotoxin host cells cytokines stimulate
the release of proteolytic enzymes and increase leukocyte
migration
Overview
2-Etiology
Proteolytic enzymes damage joint cartilage +
collagen matrix
inflammatory mediators, bacteria, and pus
increase pressure within the joint Pressure
necrosis destroy synovium or cartilage
Distension of the joint capsule may cause laxity,
with possible subluxation or dislocation as a
sequela
Overview
2-Etiology
hematogenous spread
direct inoculation
extension of a contiguous focus of infection
(e.g., osteomyelitis).
Overview
2-Etiology
neonates and young children often have coexisting septic arthritis
and osteomyelitis.
capsule insertion allowing bone infection to invade the joint space.
Nutrient capillaries & physeal plate relationship
osteomyelitis SA in 35%
SA secondary osteomyelitis RARE
s.aureus
streptococci
Gram negative
Gram positive
Overview
2-Etiology-microbiology
H. influenzae
N.meningitidis
N.gonorrheae
K.Kingae
Salmonella
Overview
2-Epidemiology
Children > adults
< 3 years
Boys to girls 1.2-2 to 1
Lower extremity 80% Hip & knee +++
upper extremity Elbow
Neonates polyarticular SA.
Risk factors for SA in neonate
(younger than one month)
#Umbilical vessel catheterization
#Presence of central venous catheters
#Femoral vessel blood sampling
#Osteomyelitis
Risk factors for SA in older infants and
children
Immunodeficiency
joint surgery
Hemoglobinopathies
underlying arthritis == JIA
Diabetes
Overview
3-Prognosis
poor outcome associated with :
Time to diagnosis is the most important prognostic factor (>4-7 days)
Involvement of the hip
Involvement of the hip or shoulder with concomitant osteomyelitis
Young age (i.e., less than one year)
The causative organism (Enterobacteriaceae and S. aureus)
Presentation
1-History
The presentation age , site , organism.
Neonates and infants : = septicemia ( irritability,
apprehension, poor feeding) or fever without a focus of
infection .
lack of use of the involved extremity ("pseudoparalysis")
discomfort when handled or having the diaper changed.
extremity swelling.
Presentation
1-History
Older children and adolescents :
fever and constitutional symptoms (malaise, poor appetite,
irritability, tachycardia)
Joint findings (e.g. swelling, tenderness) are generally present but
may be subtle.
Pain with active or passive movement is a cardinal feature.
limp or refusal to walk or bear weight.
Referred pain :
SA of hip knee pain
SA of sacroiliac joint symptoms may mimic
appendicitis, pelvic neoplasm, or urinary tract infection
Presentation
2-Physical Examination
Decreased or absent ROM, joint tenderness, swelling, warmth,
and erythema.
Joint position :
hip is flexed, abducted, and externally rotated.
The knee, ankle, and elbow are partially flexed.
shoulder is adducted and internally rotated.
Fever: mostly low-grade
DDX
Transient Synovitis:
Kocher’s Criteria :
1)
Fever +++
2)
difficulty of bearing weight on a limb
3)
ESR > 40 mm/hr
4)
peripheral (WBC) > 12,000 cells/μL
were independent variables that best distinguished SA from transient
synovitis.
Slipped capital femoral epiphysis
Perth's disease
Clinical features, imaging studies, and/or synovial fluid analysis usually
differentiate these conditions from acute SA.
Workup
Diagnosis = clinical findings + synovial fluid analysis
low threshold for performing arthrocentesis
Workup
1-laboratory studies
Blood tests (CBC ,ESR ,C-RP , culture)
Synovial fluid WBC , Gram stain , culture , and
susceptibility test.
Additional lab. Studies when particular organisms are
suspected
Workup
1-laboratory studies - Blood tests
Peripheral WBC +ESR+C-RP usually elevated…some cases mildly
elevated
ESR and/or C-RP are better – than + predictors of SA.
ESR > 20 mm/hr in most children with SA …mean= 55mm/hr
rise for 35 days after institution of appropriate therapy …my still
raised for 30 days.
C-RP mean=8.5 mg/dl…rise within 3650 hrs. of onset of infection
and usually falls to normal within a week of successful treatment
Better than ESR to monitor response to treatment
Workup
1-laboratory studies - Blood tests
aerobic blood cultures in all patients in whom SA is a consideration
anaerobic cultures should be obtained if anaerobic infection is a
concern (eg, direct inoculation).
Blood cultures are positive in approximately 40% of cases and
sometimes yield the pathogen when joint fluid cultures are
negative .
Workup
1-laboratory studies – synovial fluid
Aspiration ASAP = identification of organisms + joint
decompression
Hip aspiration + imaging guidance to confirm joint entry
heparinized syringe so that clot formation does not preclude
enumeration of leukocytes
Workup
1-laboratory studies – synovial fluid
synovial fluid should be obtained for (CBC), glucose, Gram stain, and culture.
Synovial culture has poor sensitivity (60-70%)
S. fluid WBC > 50,000/µL suggests SA, especially if> 100,000/mL or if a
predominance of polymorphonuclear cells
The S. fluid glucose 30% of that in the serum,unique to SA.
The S. fluid WBC <50,000 cells/microL in patients with unusual causes of bacterial
arthritis (eg, Brucella) and may >50,000 cells/microL in children with JIA, serum
sickness, or reactive arthritis.
Workup
1-laboratory studies – synovial fluid
Gram stain — bacteriostatic effects. Approximately 40- 50% of joint aspirates
are sterile…
Culture — The identification of organisms in joint fluid is the primary criterion
for the diagnosis of SA.
Synovial fluid cultures are positive in approximately 50-60% of patients with
other clinical and laboratory findings of bacterial arthritis.
False negative synovial fluid cultures may occur with fastidious organisms,
inadequate laboratory techniques, or prior treatment with antibiotics.
Workup
1-laboratory studies – synovial fluid
Other studies
Polymerase chain reaction (PCR) testing for Kingella kingae and other
fastidious pathogens.
Serology for Borrelia antigens should be sent when Lyme-diseaserelated articular disease is suspected.
Workup
2-imaging studies
plain radiography
is insensitive… may be most helpful in screening for etiologies other
than SA as a cause of joint pain. E.g. bony changes suggestive of
osteomyelitis, bony tumors or fractures as the source of swelling, and
Legg-Perthes disease or a slipped capital femoral epiphysis.
Ultrasonography
Hip effusion & to guide the aspiration needle if an effusion is detected.
Scintigraphy
limited role , may be helpful if multifocal disease is suspected in
neonates
assists with the detection of an associated osteomyelitis.
Treatment
The Goals:
sterilization and decompression of the joint space
removal of inflammatory debris to relieve pain and prevent deformity
or functional sequelae .
Clinical decision making in the management of the child with
bacterial arthritis includes the following questions :
How should the joint be drained and irrigated?
Which antibiotics should be administered?
What is the optimal duration of antimicrobial therapy?
When is it safe to switch from parenteral to oral therapy?
Treatment
Hospitalize
Obtain cultures initiate empiric antibiotics before culture results.
immobilization 2-3 days then Encourage early passive ROM to stretch
tendons and prevent contractures.
Medication- Drainage (arthrotomy , arthroscopy, needle aspiration)
Medications
ASAP after cultures
All antibiotics that have been studied readily enter the joint fluid after systemic
administration; intraarticular injection of antibiotics is unnecessary.
Most children can be treated with sequential antibiotic therapy (parenteral oral)
to minimize the length of hospital stay and complications from prolonged vascular
access.
Adjunctive therapies:
Analgesia :Opioid (codeine or morphine)acetaminophen or ibuprofen
NSAIDs :
reactive synovitis associated with bacterial arthritis
Dexamethasone ??!! :for the first four days of therapy//remains investigational
Medications
Empiric therapy:
- based on age ,clinical features , Gram stain, and local
bacterial susceptibility patterns.
- includes coverage for S. aureus in all ages.
-Commonly used drugs are listed in the table
Medication
Empiric therapy
Birth to 3 months: S.aureus , GAS S. , G- bacilli
An antistaphylococcal agent (nafcillin, oxacillin, or vancomycin)
Gentamycin or cefotaxime
vancomycin should be included in the regimen for neonates who have been in the
ICU for more than one week because of the risk of nosocomial infection with
(MRSA) or coagulase-negative staphylococci.
Medication
Empiric therapy
Older than three months : S. aureus , G+ organisms (GAS S. , pneumococci).
Additional coverage for other pathogens (K. kingae, [Hib], Neisseria gonorrhoeae)
may be necessary in select populations.
antistaphylococcal and antistreptococcal agents :
nafcillin , clindamycin , vancomycin , Cefazolin
Medication
Specific therapy
Specific therapy
S.aureus 3weeks
Pneumococci/N. meningitidis 2weeks
discontinue if ESR and/or CRP have returned to normal by these time
points and there is no radiographic evidence of unsuspected
osteomyelitis.
Longer courses may be necessary for SA of the hip, and for arthritis
caused by Enterobacteriaceae or other unusual organisms.
1970s
Medication
Specific therapy- Route
Start parenterally
In neonates (<1 month), the entire course should be administered parenterally .the
gastrointestinal absorption is unpredictable
>1 month, continue parenterally at least until clinical and laboratory improvement have been
demonstrated orally
Clear improvement usually is established 5 to 10 days after initiation of antibiotic therapy. It is
indicated by achievement of each of the following conditions:
*The patient has been afebrile for 48 to 72 hours
* Local signs and symptoms of infection are reduced considerably
*WBC has normalized
*CRP and/or ESR has decreased
Oral Antibiotics
Complete the course in ages >1 month providing unequivocal improvement
In randomized and observational studies, treatment of SA with IV antibiotics
for short periods (approximately seven days) followed by oral therapy, was as
successful as longer courses of parenteral therapy.
Subsequent oral therapy may be substituted for parenteral treatment
provided that certain criteria are met:
1)
Clear demonstration of clinical and laboratory improvement (ie, swelling,
tenderness, and erythema, reduction of C-reactive protein)
2)
Decreasing or absent fever
3)
oral agent with appropriate coverage is available in a formulation that the
child can swallow
4)
Adherence to the antibiotic and monitoring regimen are assured
Oral Antibiotics
Cultures
local
isolated organism susceptibility test
not isolated age, clinical features, Gram stain, and
bacterial susceptibility patterns.
Similar spectrum:
Cefazolin
cephalexin
Clindamycin oral clindamycin
higher doses than antibitics used for treatment of other infections and
recommended in package inserts
The initial doses of oral therapy should be administered while the child is in
the hospital to ensure that the drug is tolerated.
DRAINAGE
Drainage V.S. no drainage ?? Human/animals
Arthroscopy
alternative for drainage , particularly for SA of the knee.
successful arthroscopic drainage of the hip also has been reported,
but the number of cases successfully managed is small and largely
involves older children.
Successful management of SA of the shoulder joint of infants has also
been described.
When arthroscopic drainage is performed, the surgeon must obtain a
full view of the interior of the joint to ensure that no loculated
pockets of purulent material remain after the procedure
Needle aspiration
discomfortable.
minimal morbidity , in the older child, may not require
general anesthesia
for uncomplicated SA involving joints other than the hip or
shoulder, serial needle aspirations are performed.
These may be discontinued once fluid no longer
reaccumulates.
RESPONSE TO THERAPY
Clinical and laboratory improvement is indicated by:
Resolution of fever
Decreased joint pain, swelling, and erythema
Increased joint mobility
Decrease in peripheral WBC count and synovial fluid WBC
Decrease in ESR and/or CRP
Complications
Joint laxity, subluxation, or dislocation
Joint restriction
Limb-length discrepancy (if the growth plate is involved)
Avascular necrosis
Enlargement of the femoral head (coxa magna) in bacterial arthritis of the hip
Pathologic fractures
The reported complication rates vary depending upon the patient population, the
involved joint, and the duration of follow-up:
residual dysfunction is 10 to 25 percent.
Even with appropriate management, approximately 40% of patients with hip
involvement and 10% of patients with knee involvement develop significant
complications