ABSTRACT
Septic arthritis is more common than osteomyelitis in infancy and childhood though both can occur concurrently. Children under the age of five years appear to be far more susceptible to developing septic arthritis and account for 75 percent of all cases of acute septic arthritis. Among the organisms that cause septic arthritis, the most common is Staphylococcus aureus. Potent proteolytic enzymes are released by the bacteria and by activated polymorphs, synovial cells and chondrocytes during the inflammatory reaction in response to the infection in the joint. These enzymes cause degradation of the hyaline cartilage with depletion of the collagen and the glucosaminoglycans. A combination of vascular damage and proteolytic degradation contribute to damage to the growth plate. In children with septic arthritis of the hip the blood supply to the femoral head may be disrupted by tamponade due to the increased intra-articular pressure that develops as pus accumulates in the joint.
