Septic arthritis should be suspected in children that have a painful joint especially if they do not want to weight bear. Orthopedics uses the Kocher Criteria to determine the probability of whether the joint is infected.
Four elements make up the criteria:
Erythrocyte Sedimentation Rate >40
WBC > 12
Non weight-bearing on the affected joint
Fever.
If only one sign is present there is a 3% chance the child has a septic joint.
