Septic Hip

Question 1

What are risk factors for neonatal septic arthritis?

Answer 1

1) prematurity
2) C-section

Hip MC joint involved; 35%
50% of cases occur in pts younger than 2yrs of age

Question 2

Which joints have an intra-articular metaphysis in pediatric patients?

Answer 2

1) hip
2) shoulder
3) elbow
4) ankle

Question 3

What causes the destruction of cartilage in pediatric septic arthritis?

Answer 3

Release of proteolytic enzymes (matrix metalloproteinases) from inflammatory and synovial cells, cartilage, and bacteria which may cause articular surface damage within 8 hours

Question 4

What is the most common cause of septic arthritis in various age groups?

Answer 4

Neonates- group B strep
Infants- staph aureus
Toddlers- staph aureus
Adolescents- Neisseria gonorrhea
Adults- staph aureus

Group A beta-hemolytic strep is MC following varicella infxn
HACEK organisms can also be a cause

Question 5

What are some poor prognostic factors in septic arthritis?

Answer 5

1) age less than 6 months
2) associated osteomyelitis
3) hip joint (versus knee)
4) delay >4 days until presentation

Question 6

What are the Kocher criteria for pediatric hip septic arthritis?

Answer 6

1) Fever > 101.3°F (38.5°C)
2) WBC > 12,000
3) ESR > 40
4) inability to bear weight
90% chance of septic arthritis if 3 out of 4 present

Additionally CRP > 2.0mg/dL
Fever is greatest predictor followed by CRP >2.0 mg/dL

Question 7

What is the treatment for a pediatric patient with septic arthritis?

Answer 7

Emergent I and D followed by abx

Cartilage damage within 8hrs

Question 8

What are some clues to differentiate psoas abscess from septic hip and a pediatric patient?

Answer 8

Signs unique to psoas abscess include sciatica, femoral nerve neuropathy, bladder irritability (from psoas compression). A psoas abscess can give rise to a sympathetic sterile hip effusion.