Except in very young children, the infection rarely extends across the physical barrier of the growth plate. In children younger than 1 year of age, some branches of the metaphyseal arteries pass through the growth plate to nourish the epiphysis. The passageways for these vessels allow the infection to spread into the epiphysis, then into the adjacent joint space itself.

Occasionally, the body’s immune response can effectively eradicate a minor infection in the metaphysis. If the area of infection is walled off and the infecting bacteria are killed, the small, residual abscess cavity may persist indefinitely. The cavity, composed of fibrous tissue but containing no residual viable bacteria, is called a Brodie abscess, even though there is no residual active infection present. In contrast, a more aggressive and virulent infection continues to destroy bone and eventually creates a draining sinus. The sinus will drain until the necrotic and infected tissue is completely removed and replaced with fibrous tissue or noninfected bone.

Early and aggressive diagnosis and treatment of hematogenous osteomyelitis can arrest the destruction of normal, healthy bone by the extending abscess. Treatment includes administration of bacteria-specific antibiotics and surgical drainage of the infectious focus. Usually, antibiotics are administered intravenously over a period of at least 4 weeks, but they can be required for longer periods (months). Sometimes oral antibiotics can be used later in the treatment. Therefore, it is especially important to understand the early clinical manifestations of this disease so that appropriate therapy can be initiated promptly.