Osteomyelitis is an inflammation of bone caused by bacterial infection. It can be acute (<2 weeks), subacute (2-6 weeks), or chronic (>6 weeks) depending on duration and symptoms. Common causative organisms are Staphylococcus aureus and other staph species. In children, S. aureus and group B streptococcus are frequent causes. Chronic osteomyelitis is characterized by necrotic bone (sequestrum) surrounded by inflammatory tissue (involucrum). Symptoms include pain, swelling, and draining sinuses. The metaphysis of long bones is a common site due to its vascular anatomy.