Earliest site of bone involvement in acute hematogenous osteomyelitis in children is:
In acute hematogenous osteomyelitis in children, the metaphysis is commonly involved. The end vessels of the nutrient aery empty into much larger sinusoidal veins, causing a slow and turbulent flow of blood at this junction. These conditions predispose bacteria to migrate through adjacent gaps in the endothelium. Also, low oxygen tension in this region may compromise phagocytic activity of white blood cells. Thrombosis caused by infection results in a region of avascular necrosis that may lead to abscess formation. Must know: Staphylococcus aureus, Streptococcus, and Haemophilus influenzae are the most common causes of acute hematogenous osteomyelitis in children. The most common causes of septic ahritis are Neisseria gonorrhoeae, S. aureus, and group A Streptococcus. Ref: Wilson S.C., Skinner H.B. (2006). Chapter 8. Ohopedic Infections. In H.B. Skinner (Ed), CURRENT Diagnosis & Treatment in Ohopedics, 4e.
Metaphysis
Diaphysis
Epiphysis
Point of entry of the nutrient aery