JOINT INFECTIONSJOINT INFECTIONS

K. Bougoulias

Septic arthritisSeptic arthritis

Haematogenous spread to synoviumExtension of osteomyelitis involving

epiphysis or intracapsular metaphysisDirect contamination following diagnostic/

therapeutic procedures

Saunders 1981

Clinical featuresClinical features

FeverSwelling/ synovial effusionLimitation of joint movementsUsually monoarticular involvement (knee

most common)

Clinical featuresClinical features

50% have history of preexisting arthritis- 30% history of trauma (Cooper, Cawley. Ann Rheum Dis 1986)

-Rheumatoid arthritis may have multiple joint involvement (Gardner, Am J Med 1990)

-Sternoclavicular & sacroiliac joints often affected in iv drug users (Philips 1984)

Bacterial etiologyBacterial etiology

<2 years of age

2-16 years 16-30 years of age

>30 years of age

Haemophilus inluenzae, S.aureus

S.aureus, S. pyogenes Neisseria gonorrhoeae,

S.aureus S.aureus, Streptococci

Risk factors associated with Risk factors associated with pathogenspathogens

Neisseria gonorrhoeae Sexual activity

Strept. pneumoniae Sickle cell disease

Gram-neg bacilli UTI

Eikenella corrodens Human bite

Pasteurella multocida Cat/ dog bite

Borrelia burgdorferi Tick exposure

Sporothrix schenckii gardeners

Mycobacterium marinum Tropical fish

Candida species Trauma, steroid inj

Pseudoallescheria Trauma

Radiographic studiesRadiographic studies

X rays: asymmetrical soft tissue shadows (displacement of muscles)- comparison with other side usefull

Destruction of subchondral bone and articular cartilage

Infraction and sequestration of epiphysis

Arthrography helpful in unossified nucleus

Radiographic StudiesRadiographic Studies

Bone, indium and gallium scans positive in Septic arthritis (routine imaging is not necessary unless osteomyelitis is suspected)

CT, MRI, Sonography: more sensitive in detecting joint effusions

Diagnostic aspirationDiagnostic aspiration

Synovial fluid analysis at the earliest possible moment

Bacteriologic studies & white blood and differential blood cell counts

Average of 100,000 cells/mm3 (range 25,000 to 250,000)

Strong suspicion: >50,000 cells/mm3 with 90% polymorphs

AspirationAspiration

Gram stain give guidance to most effective antibiotic treat before sensitivity tests

Blood cultures, cultures from other septic areas

Glucose concentration in synovial fluid is less than blood levels

AspirationAspiration

Protein may be up to 6 or 8 g/Dl-electrophoretic pattern resembling of plasma

Urate or calcium pyrophosphate crystals are important in differencial diagnosis

Nade S, JBJS 1983

Ward et al, Arthritis Rheum 1960

Differencial DiagnosisDifferencial Diagnosis

BursitisCellulitisTransient synovitisAseptic inflammationAcute osteomyelitisCrystal deposition diseaseAcute rheumatoid arthritis

Differential diagnosisDifferential diagnosis

Chronic arthritisAcute rheumatic feverHemophilia

TreatmentTreatment

Parenteral antibiotics immediately upon admission

Type of antibiotics: natural history of disease, age, Gram stain

<5 years old :empiric therapy against H.influenza, S.aureus, Streptococci- Cefotaxime, ceftizoxime

TreatmentTreatment

Sexually active adult, ceftriaxone, if gram stain is suggestive of gonococcus

Combination of vancomycin and gentamycin against S.epidermidis and S.aureus

Usual length 2-3 weeks

Surgical DrainageSurgical Drainage

Serial aspirationOpen surgical drainageArthroscopic lavageInstilling antibiotics locally is not helpful,

may be harmful

Bobechko, pediatric Orth 1978

Nade S, JBJS 1983

ImmobilizationImmobilization

Traditional for pain relieve, but…Continuing passive motion: improves

nutrition of cartilage, prevents adhesions, enhances clearance of lysosomal enzymes,stimulate chondrocytes to synthesize matrix components

Salter RB et al, Clin Orthop. 1981

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