Septic Arthritis

Question 1

What is Septic Arthritis?

Answer 1

Infection within a joint - emergency as the infection can quickly begin to destroy the joint and cause systemic illness.

Question 2

Clinical Features of Septic Arthritis (3).

Answer 2

1. Hot, red and swollen painful joint.
2. Stiffness and reduced range of motion.
3. Systemic symptoms.
   * only a single joint - often the knee, with rapid onset.

Question 3

Aetiology of Septic Arthritis (5).

Answer 3

1. S. aureus (commonest).
2. N. gonorrhoea (sexually active).
3. Group A Streptococci (S. pyogenes).
4. H. influenzae.
5. E. coli.

Question 4

Differential Diagnoses of Septic Arthritis (4).

Answer 4

1. Gout.
2. Pseudogout.
3. Reactive Arthritis.
4. Haemarthrosis (bleeding into joint).

Question 5

Diagnosis of Septic Arthritis (4).

Answer 5

KOCHER CRITERIA :
1. Fever > 38.5.
2. Non-Weight Bearing.
3. Raised ESR.
4. Raised WCC.

Question 6

Investigations of Septic Arthritis.

Answer 6

SYNOVIAL FLUID SAMPLING : Aspirate Joint - send sample (may contain pus) for MC&S, gram staining, crystal microscopy.

Question 7

Management of Septic Arthritis (4).

Answer 7

1. Low Threshold (examine joint fluid).
2. Local Hot Joint Policy - which team admits, what antibiotics to use, and how long.
3. Empirical IV Antibiotics until Sensitivities are known.
4. Needle Aspiration +/- Arthroscopic Lavage.

Question 8

Antibiotic Therapy in Septic Arthritis (4).

Answer 8

1. 3-6 weeks.
2. Local guidelines.
3. 1st Line - Flucloxacillin + Rifampicin.
4. Penicillin Allergy, MRSA, Prosthetic Joint - Vancomycin + Rifampicin or Clindamycin.

Question 9

Complications of Septic Arthritis (3).

Answer 9

1. Osteomyelitis.
2. Arthritis.
3. Ankylosis Fusion.