Septic arthritis
Definition
Infectious arthritis is an inflammation of a joint caused by infection. Bacterial, viral, or fungal infections can spread from another part of the body to a joint, causing infection.
Infection and inflammation in a joint can damage the cartilage and synovium. This causes arthritis. Infectious arthritis is also known as septic arthritis.
Pathophysiology
Bacteria can gain entrance to a joint via 3 routes:
Haematogenous - Most common form of spread usually affect people with underlying medical problem.
Direct inoculation - May result from penetrating trauma Introduction of organisms during diagnostic and surgical procedures. For eg arthroscopy and intra-articular injection
Direct spread from adjacent focal infection
…show more content…
Partly by the bacterial enzyme, and partly by the enzyme released from synovium, inflammatory cell and pus.
• Effect confined on articular cartilage. Extensive erosion can occur due to synovial proliferation and ingrowth.
Causes
• Septic arthritis develops when bacteria, virus of fungi spread through the blood to a joint.
• It may also occur when the joint is directly infected with a microorganism from an injury or during surgery. Joints that are commonly affected are the knee and hip.
• Most cases of acute septic arthritis are caused by bacteria such as Staphylococcus or Streptococcus.
• Chronic septic arthritis (which is less common) is caused by organisms such as Mycobacterium tuberculosis and Candida albicans.
• Once the infection reaches a joint, the joint cannot protect itself from the invading bacterium, virus, or fungus.
• The body’s reaction to an infection in the joint includes inflammation, increased pressure, and reduced blood flow to the joint. This also adds to the damage of the joint.
Risk factors for septic arthritis
• Artificial joint implants
• Bacterial infection somewhere else in your body
• Presence of bacteria in your blood
• Chronic illness or disease (such as diabetes, rheumatoid arthritis, and sickle cell