Septic arthritis

1. What is the clinical picture of septic arthritis?
*2. What are the most common bacterial causes of septic arthritis in different age groups?
3. How is septic arthritis diagnosed?
4. What is the treatment of septic arthritis?
5. What are risk factors for septic arthritis?

Answers:
1. Rapid onset of monoarticular joint pain, erythema, decreased ROM. Most common in the knee.
2. Neonates: S aureus and GBS. Infants: H flu. Children: S aureus. Adults: gonorrhea.
3. Synovial fluid analysis with pos culture, >100,000 WBC, >85% PMN. Plain films with show soft tissue swelling early with later joint space narrowing, erosions, and gas formation.
4. Antibiotics, frequent needle aspirations with arthroscopic lavage.
5. Risk factors include age, prosthetic joints, anemia, chronic disease, hemophilia.