This document discusses the pathophysiology of sequestrum in osteomyelitis. It classifies osteomyelitis by duration, mechanism, and host response. The most common causative microorganisms are Staphylococcus aureus overall and Pseudomonas in IV drug users. Clinical features include pain, swelling, fever and pseudoparalysis. Two specific types discussed are Brodie's abscess, which presents as a bone abscess surrounded by sclerosis, and sclerosing osteomyelitis of Garre, which involves nonsuppurative sclerosis of the jaw.

1. PATHOPHYSIOLOGY OF
SEQUESTRUM
S.PAVAN SAGAR
ROLL NO:173

2.  CLASSIFICATION OF OSTEOMYELITIS:
 Duration - Acute / Subacute / Chronic
 Mechanism - Heamatogenous(Blood)/
Exogenous (open fractures)
 Host response - Pyogenic / Granulomatous

3. CAUSATIVE MICROORGANISMS:
 Overall most common cause:S.aureus
 Most common cause in I.V drug abusers:Pseudomonas
 Most common cause in Sickle cell disease:Salmonella
 In Neonates:Group b streptococci
Most common route of spread:Hematogenous especially in children
Most common route in adults:Spread from contigious site,
Post Traumatic,Open fractures.

9. Clinical features:
 Overall most common site:Metaphysis of distal femur
 Most common site in adults:Thoracolumbar spine
 pain or tenderness, swelling,fever,
 Pseudoparalysis
 In Adults:Backache,and fever
 In Infants:Delayed growth

12. Brodie abcess
 Bone abscess containing pus or jelly like granulation tissue surrounded by a
zone of sclerosis
 Age 11-20 yrs, metaphyseal area, usually upper tibia or lower femur
 Intermittent pain, worse at night, relieved by rest
 Circular or oval luscency surrounded by zone of sclerosis
Sclerosing osteomyelitis of Garre:
 Sclerosing, nonsuppurative
 Jaw (mandible)
 No abcess, cortical thickening due to excess periosteal reaction
 Main concern is Swelling