OSTEOMYELITIS & SEPTIC ARTHRITIS Flashcards
How the pathogen reach the bone ?
1- Hematogenous route 2- Contiguous soft tissue focus ( post operative infection, contaminated open fracture, soft tissue infection , puncture wounds)
3- In association with peripheral vascular disease (diabetes mellitus ,severe atherosclerosis, vasculitis)
• May have a short duration ( few days for hematogenous acquired
infection) or may last several weeks to months ( if secondary
to contiguous focus of infection).
S. aureus, group B Streptococcus,Gram negative rods (eg. E. coli, Klebsiella ).
Common in ?
Infants
S. aureus, group A Streptococcus & H.
influenzae
Common in ?
Children
S. aureus
Common in ?
Adults
Salmonella species
Common in?
Sickle cell disease
S. aureus, group A Streptococcus, Gram
negative rods, anaerobes.
Common in >
Infection after trauma ,injury or surgery
Pseudomonas aeruginosa, S. aureus
Common in ?
Infection after puncture wound of foot.
Mycobacterium tuberculosis or M. avium.
AIDS patients
acute osteomyelitis
Clinically?
fever, localized pain , heat , swelling, tenderness of affected site ( one or more bones or joints affected in hematogenous spread). May be local tissue infection ( abscess or wound) .
acute osteomyelitis
Blood tests:?
leukocytosis, high ESR and C-reactive
protein.
acute osteomyelitis
• X-ray? Ultrasound? CT scan? MRI?
• X-ray : normal at early stages. Swelling of soft tissues
followed by elevation of periosteum , demineralization and
calcification of bone later on.
• Ultrasound: fluid collection (abscess) and surface
abnormalities of bone. • CT scan: reveal small areas of osteolysis in cortical bone. • MRI : early detection ,help in unclear situations. Defines
bone involvement in patients with negative bone scan.
Diagnosis of acute osteomyelitis?
Blood culture: bacteremia common.
Biopsy of periosteum or bone or needle aspiration of
overlying abscess if blood culture is negative.
Blood test: complete blood and differential counts .
Erythrocyte sedimentation rate ( ESR) .
C-reactive protein
Imaging studies: X-RAY, MRI, CT-SCAN
Complications of acute osteomyelitis include?
oSeptic arthritis
oChronic osteomyelitis
oMetastatic infection to other bones or organs
oPathological fractures
Chronic Osteomyelitis
Infection due to?
hematological spread is rare.
Chronic Osteomyelitis
Infection are ?
secondary to a contiguous focus or
peripheral vascular disease.
Chronic Osteomyelitis
Most common pathogen ?
• S. aureus is the most common pathogen.
? And ? clinically have
indolent “chronic” course
?
Tuberculosis and fungal osteomyelitis
Chronic Osteomyelitis
? And ? may be the cause in
immunosuppressed patients.
Mycobacteria and fungi
common in KSA. ?
Chronic Osteomyelitis
TB & Brucella
Diagnosis of chronic osteomyelitis
?
• Blood culture is not very helpful because bacteremia is
rare.
• WBC usually normal, ESR elevated but not specific.
• Radiological changes are complicated by the presence of
bony abnormalities.
• MRI helpful for diagnosis and evaluation of the extent
of disease.
Management & Treatment
Of chronic osteomyelitis
• Extensive surgical debridement with antibiotic therapy.
• IV antibiotics for 3-6 weeks followed by long term oral
suppressive therapy.
• Some patients may require life long antibiotic ,others for
acute exacerbations.
Is an acute inflammation of the joint space secondary to
infection. ?
Septic (Infectious) Arthritis:
Generally affects a single joint and results in suppurative
inflammation.
?
Septic Arthritis
Haematogenous seeding of joint is most common.
In ?
Septic Arthritis
Septic Arthritis
Common symptoms?
Diagnosis by ?
Management?
Common symptoms: pain, swelling, limitation of movement. Diagnosis by Arthrocentesis to obtain synovial fluid for
analysis; Gram stain, culture & sensitivity.
Drainage & antimicrobial therapy important management.
Common causes of septic arthritis
S. aureus, group B Streptococcus, Gram
negative rods ( e.g. E. coli, Klebsiella,
Proteus, Pseudomonas) .
Common in ?
Neonates
Common causes of septic arthritis S. aureus, group A Streptococcus, S. • Infants /children pneumoniae, H. influenzae type b Common in ?
Infants. Children
S. aureus, Neisseria gonorrheae
Common organism
septic arthritis
?
Adults
Salmonella species
septic arthritis
Common in ?
Sickle cell disease
S. aureus
Common in ?
Septic arthritis
Trauma /surgical procedure
septic arthritis
Mycobacterium tuberculosis , Fungi
Common in ?
Chronic arthritis
Other causes of septic arthritis
Reactive arthritis due to: ?
- Campylobacter jejuni
- Yersinia enterocolitica
- Some Salmonella species
Other causes of septic arthritis
Non-infectious causes of arthritis?
- Rheumatoid arthritis
- Gout
- Traumatic arthritis
- Degenerative arthritis
Risk factors
Of septic arthritis
?
- Gonococcal infection :
• Most common cause in young, sexually active adults.
• Caused by Neisseria gonorrheae .
• Leads to disseminated infection secondary to
urethritis/cervicitis
. • Initially present with polyarthralgia, fever, skin lesions. - Non-gonococcal arthritis :
• Occurs in older adults. • Results from introduction of organisms into joint space as
a results of bacteremia or fungaemia from infection at
other body sites. - Lyme disease due to tick bite in endemic areas.
Uncommon in KSA.
Diagnosis of Septic Arthritis
?
- History/examination to exclude systemic illness. Note
history of tick exposure in endemic areas - Arthrocentesis should be done as soon as possible;
1- Synovial fluid is cloudy and purulent.
2- Leukocyte count generally > 25,000/mm3,with
predominant neutrophils.
3- Gram stain and culture are positive in > 90% of cases.
4- Exclude crystal deposition arthritis or non-infectious
inflammatory arthritis. - Blood cultures indicated
• If Gonococcal infection suspected, take specimen
from cervix, urethra, rectum for culture or DNA testing
for N. gonorrheae.
• Investigate for other sexually transmitted diseases.
• Culture of joint fluid.
Management & treatment
Of septic arthritis?
- Arthrocentesis with drainage of infected synovial fluid.
• Repeated therapeutic Arthrocentesis often needed.
• Occasionally, surgical drainage/debridement
• Antimicrobial therapy should be directed at the suspected
organism and susceptibility results
