Differentiates septic arthritis of the hip from transient synovitis in a limping child.
The Kocher Criteria (Septic Arthritis) is a infectious scoring tool used in paediatric practice. Differentiates septic arthritis of the hip from transient synovitis in a limping child. It scores 4 criteria and interprets the total across 5 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.
4. They are Non-weight-bearing on the affected side; Temperature > 38.5 °C; ESR > 40 mm/hr; Serum WBC > 12 000 /µL.
The total is interpreted as: any score - < 0.2 % probability: 0 predictors - septic arthritis very unlikely (<0.2%). Transient synovitis more likely; reassess if the child deteriorates; 1 predictor or more - ≈ 3 % probability: 1 predictor - roughly 3% probability. Observe closely; consider ultrasound and repeat examination; 2 predictors or more - ≈ 40 % probability: 2 predictors - roughly 40% probability. Strongly consider joint aspiration and orthopaedic referral; 3 predictors or more - ≈ 93 % probability: 3 predictors - roughly 93% probability. Urgent orthopaedic referral and joint aspiration; 4 predictors or more - ≈ 99 % probability: all 4 predictors - approximately 99% probability of septic arthritis. Emergency orthopaedic referral for aspiration/washout.
No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.
Derived for the paediatric hip; CRP >20 mg/L is a further independent predictor in later validation studies.
Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.