Osteomyelitis Flashcards
What is Osteomyelitis?
Inflammation in a bone and bone marrow, usually caused by bacterial infection.
What is Haematogenous Osteomyelitis?
When a pathogen is carried through the blood (bacteraemia) and seeded in the bone (commonest form in adults : vertebral osteomyelitis).
What are the modes of infection spread to cause Osteomyelitis?
- Haematogenous (mono microbial usually) - commoner in kids.
- Direct Contamination e.g. Fracture Site/Operation (polymicrobial usually) - commoner In adults.
Risk Factors of Osteomyelitis (8).
- Open Fractures.
- Orthopaedic Operations (Prosthetic Joints - preoperative prophylactic antibiotics).
- Diabetes (especially Diabetic Foot Ulcers).
- Peripheral Arterial Disease.
- IV Drug Use.
- Immunosuppression.
- Infective Endocarditis (Haematogenous).
- Sickle-Cell Anaemia (Haematogenous).
When are prosthetic joint infections most likely to occur?
Revision surgery > initial joint replacement surgery.
Commonest causative organisms of Osteomyelitis (2).
- Mostly S. aureus or Coagulase Negative Staphylococci.
2. Salmonella species in Sickle-Cell Anaemia.
Clinical Presentation of Osteomyelitis.
Fever & Joint Pain, Tenderness, Erythema and Swelling.
Investigations of Osteomyelitis (3).
- X-Rays (not useful in early disease) - but potential signs.
- MRI - best for diagnosis.
- Bloods - Inflammatory Markers, Cultures.
Potential Signs on an X-Ray of Osteomyelitis (3).
- Periosteal Reaction (changes to surface of bone).
- Localised Osteopenia (thinning of bone).
- Destruction of areas of bone.
Management of Osteomyelitis.
Combination of Surgical Debridement (infected bone and tissues) and Prolonged Course of Antibiotic Therapy.
Antibiotic Therapy in Osteomyelitis (4).
- Acute - 6 weeks of Flucloxacillin (+/- Rifampicin/Fusidic Acid for 1st 2 weeks).
- Chronic - 3 months+ antibiotics.
- Penicillin Allergy : Clindamycin.
- MRSA : Vancomycin or Teicoplanin.
