Septic Arthritis Flashcards
(18 cards)
What is it?
Infection of either a Native or Prosthetic Joint
What causes the infection?
Usually Staphylococcus Aureus or Streptococci
How is the infection spread to the joint? (3)
- Haematogenous
- Contiguous (Spread from an adjacent area)
- Direct inoculation (trauma or surgery)
What is Medullary Arthritis?
Necrosis of the medullary contents
What is Superficial Arthritis?
Necrosis of the exposed surface
What is localised arthritis?
Stable bone with full thickness cortical sequestation
What is diffuse arthritis?
Unstable bone with extensive necrosis
Which joints are affected?
Can affect any joint but >50% of cases occur in the knee
Is it common?
1.2-2.5% of all joint prostheses become infected, and 20% of revision procedures are infected
Who does it affect?
It can affect all age groups
Risk Factors (8)
Pre-existing joint disease provides a cement for bacterial attachment, Diabetes, Immunosuppression, Chronic Renal Failure, Recent joint surgery, Prosthetic Joint, IVDU, Above 80 years old
Symptoms (7)
Painful joint, hot, erythema, swelling, pain on movement, fever, rigors
Signs (1)
Joint effusion
Differentials (7)
Rheumatoid, Osteoarthritis, Vasculitis, Gout, Reactive, Viral Arthritis, Infective Endocarditis
Investigations (11)
FBC, WCC, CRP, ESR, Joint apsiration for synovial fluid culture and sensitivity, blood cultures, PCR and Immunology, X-ray, USS, CT/MRI, Radionuclide Scan
Treatment (4)
Empirical Broad Spectrum Antibiotics IV, if S.Aureus change to Flucloxacilin for 2-3 weeks IV then Oral 2-4 weeks, Surgical drainage/debridement may be needed, limb splinted in position of function then immediate mobilisation once infection under control, Analgesia
Complications (4)
Chondral damage, future osteoarthritis, Joint replacement, Amputation
Is there a good prognosis?
Mortality is 10-20%, only 45% of patients with S.Aureus infection regain joint function
