Osteomyelitis
Osteomyelitis is an infection of the bone and bone marrow. It can be acute (hematogenous spread, common in children) or chronic (secondary to open fractures or untreated acute infection).
1. Pathological Terms
The "Classic 4":
1. Sequestrum: Dead bone separated from living bone (Floating in pus).
2. Involucrum: New bone formation surrounding the sequestrum (attempting to wall it off).
3. Cloaca: Opening in the involucrum allowing pus to discharge.
4. Sinus: Tract leading from bone to skin surface.
1. Sequestrum: Dead bone separated from living bone (Floating in pus).
2. Involucrum: New bone formation surrounding the sequestrum (attempting to wall it off).
3. Cloaca: Opening in the involucrum allowing pus to discharge.
4. Sinus: Tract leading from bone to skin surface.
2. Types
- Acute Hematogenous: Usually affects the Metaphysis of long bones in children (rich blood supply, hair-pin loop vessels, slow flow). Organism: Staph. aureus.
- Chronic: Persistent infection with sequestrum formation. Biofilm protects bacteria from antibiotics.
- Brodie's Abscess: A subacute type of osteomyelitis. Localized abscess surrounded by sclerotic bone.
3. Management
- Acute: IV Antibiotics (early), Surgical Decompression (drilling) if abscess forms.
- Chronic: Sequestrectomy (removing dead bone) and Saucerization.
25 Practice MCQs
Q1. The most common causative organism for osteomyelitis is:
Answer: A). Accounts for >80% of cases.
Q2. Sequestrum is defined as:
Answer: A). It is avascular and harbors bacteria.
Q3. Involucrum represents:
Answer: B). Body's attempt to contain the infection.
Q4. Acute hematogenous osteomyelitis usually starts in the:
Answer: A). Due to slowing of blood flow in venous sinusoids.
Q5. Salmonella osteomyelitis is characteristically seen in patients with:
Answer: A). Due to bowel infarction allowing bacterial translocation.
Q6. Brodie's Abscess is a form of:
Answer: A). Localized, walled-off infection.
Q7. Which imaging modality is most sensitive for early detection?
Answer: A). Detects marrow edema days before X-ray changes.
Q8. Cloaca is:
Answer: A). The "sewer" outlet for the bone.
Q9. The main reason antibiotics fail in chronic osteomyelitis is:
Answer: A). Biofilm makes bacteria impervious to drugs. Surgery is needed.
Q10. Tom Smith's Arthritis refers to:
Answer: A). Causes pathological dislocation and instability.
Q11. X-ray changes in acute osteomyelitis appear after:
Answer: B). 30-50% bone loss is needed to be visible.
Q12. Saucerization is:
Answer: A). Allows soft tissue to fill the dead space.
Q13. Garre's Sclerosing Osteomyelitis typically causes:
Answer: A). Non-suppurative chronic type.
Q14. Which joint is intra-articular (Metaphysis inside capsule), risking septic arthritis from osteomyelitis?
Answer: A). Infection breaks through cortex directly into joint.
Q15. Papineau technique uses:
Answer: A). For reconstructing bone defects in chronic OM.
Q16. Squamous Cell Carcinoma arising from a chronic sinus tract is called:
Answer: A). Complication of long-standing draining sinus.
Q17. CRP (C-Reactive Protein) is useful for:
Answer: A). ESR stays high for weeks ("Lag" indicator).
Q18. Antibiotic beads (PMMA) are used to:
Answer: A). Elutes drugs like Vancomycin/Tobramycin locally.
Q19. "Ring Sequestrum" is seen in:
Answer: A). Bone dies around the wire.
Q20. Vertebral Osteomyelitis usually affects:
Answer: A). Pyogenic bacteria destroy the disc quickly.
Q21. Pseudomonas osteomyelitis is common in:
Answer: A). Classic association.
Q22. The hallmark of Chronic Osteomyelitis is:
Answer: A). Often painless unless acute flare-up occurs.
Q23. Early passive ROM in osteomyelitis rehab is:
Answer: A). Rest and splinting are priorities initially.
Q24. Hyperbaric Oxygen Therapy (HBOT) works by:
Answer: A). Adjunct for refractory chronic cases.
Q25. Winquist-Hansen classification is for:
Answer: C). Cierny-Mader classifies OM (Anatomic + Physiologic host).
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