SEPTIC ARTHRITIS (Non-gonococcal acute bacterial arthritis)

Septic arthritis is an acute onset bacterial inflammation, usually involving a single joint

In > 90%), most often in knee joint and wrists.

In IV drug abusers infection of the spine and sacroiliac joints is more common.

ETIOLOGY

The most common organism of non-gonococcal arthritis is staphylococcus aureus.

Other organisms include streptococci, gram-negative bacilli such as E. coli and pseudomonas.

PREDISPOSING FACTORS

• Hematogenous spread

Microorganisms reach the joint by hematogenous spread following bacteremia, so it is important to look for evidence of septic skin lesion, abrasions, endocarditis, IV drug abuse or throat or tract infection.

• Direct entry in the joint

Organisms can directly enter the joint following penetrating wounds, local osteomyelitis or joint injection.

CLINICAL FEATURES

• Sudden onset

A typical presentation is a single painful joint, often the knee.

Other commonly affected joints are the wrist, hip, shoulder and ankle.

The joint is red, warm and swollen, with a demonstrable effusion and marked limitation of movement.

• Fever with chills in 80% of patients.

Diagnosis

Blood culture: positive in 50% of cases.

Aspiration of joint: Synovial fluid is purulent with neutrophil dominant, increased WBC

Gram stain of synovial fluid is positive in 75% of cases. Culture/sensitivity of the fluid is also performed.

• FBE shows leukocytosis.

Management

Joint immobilization

Elevation.

Admit to hospital

IV Antibiotics