UMEM Educational Pearls

Category: Orthopedics

Title: Septic Arthritis in Children

Keywords: Hip, pediatrics, arthritis (PubMed Search)

Posted: 4/22/2017 by Brian Corwell, MD (Updated: 7/18/2024)
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Septic Arthritis in Children

Classic presentation: Pain, fever (may not always be present)

Limited range of motion of joint or refusal to bear weight,

 Joint swelling (difficult to visualize in hip or shoulder),

Limb held in position that allows greatest capsular volume (elbow held in 30° flexion for example)

Diagnostic testing may include diagnostic markers (ESR, CRP) or imaging (US/MRI)

Most common organisms: Staph and Strep, Neisseria (adolescents), HACEK organisms, consider gram negatives in immunocompromised children

DDX: Transient synovitis, osteonercrosis or osteomyelitis, Psoas abscess, acute leukemia, Lyme disease

A common ED presentation is the child with the painful limp

               35% of all cases of septic arthritis

>50% of cases occur in children younger than 2yo

Hip held in flexion, Abduction, external rotation

Fever and inflammatory markers are more sensitive than WBC count and refusal to bear weight

Kocher criteria:

1)     Refusal to weight bear on affected side

2)     Sed rate greater than 40mm/hr

3)     Fever (>38.5°C

4)     WBC count of >12,000 mm3

 

IF
                 - 4/4 criteria are met, there is a 99.6% chance of septic arthritis; 
                 - when 3/4 criteria are met, there is a 93% chance of septic arthritis; 
                 - when 2/4 criteria are met, there is a 40% chance of septic arthritis; 
                 - when 1/4 criteria are met, there is a 3% chance of septic arthritis; 

 

CRP can also be incorporated into a diagnostic algorithm

CRP>2.0 (mg/dl) in a child who refuses to bear weight yields a 74% probability of septic arthritis

 

 

References

https://www.ncbi.nlm.nih.gov/pubmed/10608376