Infections

Question 1

what are risk factors for septic arthritis ?

Answer 1

Joint disease (e.g. RA)
 CRF
 Immunosuppression (e.g. DM)
 Prosthetic joints

Question 2

what organisms cause septic arthritis ?

Answer 2

staph (60%)
streps
gonococcus

Question 3

what are the symptoms and signs of septic arthritis ?

Answer 3

Acutely inflamed tender, swollen joint.
 ↓ROM
 Systemically unwell

Question 4

what investigation should be done for septic arthritis?

Answer 4

aspiration

Question 5

what would aspiration of septic arthritis show?

Answer 5

↑↑ WCC (e.g. >50,000/mm3)

Question 6

what would blood tests for septic arthritis show?

Answer 6

increased ESR, CRP, WCC

positive blood cultures

Question 7

what two antibiotics should be used for septic arthritis ?

Answer 7

vancomycin

cefotaxime

Question 8

what is the management for septic arthritis ?

Answer 8

IV Abx: vanc + cefotaxime
 Consider joint washout under GA
 Splint joint
 Physiotherapy after infection resolved

Question 9

what are the complications of septic arthritis ?

Answer 9

Osteomyelitis 
Arthritis
 Ankylosis: fusion

Question 10

what are two DD for septic arthritis ?

Answer 10

crystal arthopathy

reactive arthritis

Question 11

what organisms cause acute osteomyelitis ?

Answer 11

Staph
 Strep
 E. coli
 Pseudomonas

Question 12

what are the risk factors for acute osteomyelitis ?

Answer 12

Vascular disease
 Trauma
 SCD
 Immunosuppression (e.g. DM)
 Children
 (Rich blood supply to growth plate)

Question 13

what is the presentation for acute osteomyelitis?

Answer 13

 Pain, tenderness, erythema, warmth, ↓ROM
 Effusion in neighbouring joints
 Signs of systemic infection

Question 14

what does Xray for acute osteomyelitis show?

Answer 14

Changes take 10-14d
 Haziness + ↓ bone density
 Sub-periosteal reaction
 Sequestrum and involucrum

Question 15

what is the management for acute osteomyelitis ?

Answer 15

IV Abx: Vanc + cefotaxime until MCS known
 Drain abscess and remove sequestra
 Analgesia

Question 16

what investigation is sensitive and specific for acute osteomyelitis ?

Answer 16

MRI