1. JOINT INFECTIONS K. Bougoulias

2. Septic arthritis Haematogenous spread to synovium Extension of osteomyelitis involving epiphysis or intracapsular metaphysis Direct contamination following diagnostic/ therapeutic procedures Saunders 1981

3. Clinical features Fever Swelling/ synovial effusion Limitation of joint movements Usually monoarticular involvement (knee most common)

4. Clinical features 50% have history of preexisting arthritis- 30% history of trauma (Cooper, Cawley. Ann Rheum Dis 1986) -Rheumatoid arthritis may have multiple joint involvement (Gardner, Am J Med 1990) -Sternoclavicular & sacroiliac joints often affected in iv drug users (Philips 1984)

5. Bacterial etiology <2 years of age 2-16 years 16-30 years of age >30 years of age Haemophilus inluenzae, S.aureus S.aureus, S. pyogenes Neisseria gonorrhoeae, S.aureus S.aureus, Streptococci

7. Risk factors associated with pathogens Neisseria gonorrhoeaeSexual activity Strept. pneumoniaeSickle cell disease Gram-neg bacilliUTI Eikenella corrodensHuman bite Pasteurella multocidaCat/ dog bite Borrelia burgdorferiTick exposure Sporothrix schenckiigardeners Mycobacterium marinumTropical fish Candida speciesTrauma, steroid inj PseudoallescheriaTrauma

8. Radiographic studies X rays: asymmetrical soft tissue shadows (displacement of muscles)- comparison with other side usefull Destruction of subchondral bone and articular cartilage Infraction and sequestration of epiphysis Arthrography helpful in unossified nucleus

12. Radiographic Studies Bone, indium and gallium scans positive in Septic arthritis (routine imaging is not necessary unless osteomyelitis is suspected) CT, MRI, Sonography: more sensitive in detecting joint effusions

15. Diagnostic aspiration Synovial fluid analysis at the earliest possible moment Bacteriologic studies & white blood and differential blood cell counts Average of 100,000 cells/mm3 (range 25,000 to 250,000) Strong suspicion: >50,000 cells/mm3 with 90% polymorphs

16. Aspiration Gram stain give guidance to most effective antibiotic treat before sensitivity tests Blood cultures, cultures from other septic areas Glucose concentration in synovial fluid is less than blood levels

17. Aspiration Protein may be up to 6 or 8 g/Dl- electrophoretic pattern resembling of plasma Urate or calcium pyrophosphate crystals are important in differencial diagnosis Nade S, JBJS 1983 Ward et al, Arthritis Rheum 1960

18. Differencial Diagnosis Bursitis Cellulitis Transient synovitis Aseptic inflammation Acute osteomyelitis Crystal deposition disease Acute rheumatoid arthritis

19. Differential diagnosis Chronic arthritis Acute rheumatic fever Hemophilia

20. Treatment Parenteral antibiotics immediately upon admission Type of antibiotics: natural history of disease, age, Gram stain <5 years old :empiric therapy against H.influenza, S.aureus, Streptococci- Cefotaxime, ceftizoxime

21. Treatment Sexually active adult, ceftriaxone, if gram stain is suggestive of gonococcus Combination of vancomycin and gentamycin against S.epidermidis and S.aureus Usual length 2-3 weeks

23. Surgical Drainage Serial aspiration Open surgical drainage Arthroscopic lavage Instilling antibiotics locally is not helpful, may be harmful Bobechko, pediatric Orth 1978 Nade S, JBJS 1983

24. Immobilization Traditional for pain relieve, but… Continuing passive motion: improves nutrition of cartilage, prevents adhesions, enhances clearance of lysosomal enzymes,stimulate chondrocytes to synthesize matrix components Salter RB et al, Clin Orthop. 1981

25. Thank you