6. Bone Infections

6. Bone Infections - Pathogenesis I Infections of the Bones...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Infections of the Bones and Joints Osteomyelitis Pathogenesis I • Bone is metabolically active-- collagen and and mineral are actively remodeled – Children have growing bones – Elderly can have net loss - > brittle bones Contains: • Afferent arterial loops (no phagocytes) • Efferent loops have functionally inactive lining cells and turbulent flow Pathogenesis II Children: • Infection occurs in rapidly growing bones, primarily in metaphysis of long bones • 85% of infections in children <16yrs • infection contained by epiphyseal growth plate (1yr- puberty), extends to periosteum • infection spreads to epiphysis via perforating capillaries and growth plate destruction results • can lead to septic arthritis in children <1yr • Less damaging in adults Pathogenesis III • Acute suppurative (pussy) infection - > vascular obstruction + pus (enzymes) - > low pH - > pressure±- > edema • results in tissue necrosis, bone trabuculae (fins) break down, dissolving of calcium and matrix, spread via canals to cause vascular compromise • can lead to sequestrum (“floaties”) formation, abscess cortical destruction and pathological failure Types of Osteomyelitis I Hematogenous (spread by blood) • seen in children and adults >50 and occurs in long bones of lower extremities • caused by one of: Staphylococcus aureus, enteric gram negative baccilli , Haemophilus influenzae
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 4

6. Bone Infections - Pathogenesis I Infections of the Bones...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online