A child is brought to the casualty with a swollen, painful knee. The child has high fever with no history of trauma. Acute osteomyelitis is suspected. Which is the earliest pa of the bone to be involved in haematogenous osteomyelitis?
Acute osteomyelitis: 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. Low oxygen tension in this region may compromise phagocytic activity of white blood cells. These conditions predispose bacteria to migrate through adjacent gaps in the endothelium and adhere to the matrix. Also, 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. Bacterial Species Associated with Common Conditions: Staphylococcus aureus Most common organism in osteomyelitis, acute hematogenous osteomyelitis (90%), and infected metal implants. Group B strep Infants < 1 year old Haemophilus influenzae Children 1-16 years old Pseudomonas aeruginosa Nosocomial, puncture wound through shoe Pasteurella multocida Animal bite Eikenella corrodens Human bite Salmonella Sickle cell disease Anaerobes Diabetic ulcers, fight bites Candida albicans Immunocompromised Aspergillus Immunocompromised Atypical mycobacteria Immunocompromised Escherichia coli Neonatal Neisseria gonorrhoeae Septic ahritis in young sexually active adult 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
Area around the nutrient aery