<prompt> Which of the following is not a component of Kochers criteria when diagnosing septic arthritis of the hip?Non-weight-bearing on the affected side.Erythrocyte sedimentation rate ESR greater than 40mmhr.White blood cell WBC count of 12000mm3.C-reactive protein CRP20.  <response>: Ans. D. C-reactive protein CRP 20.Due to the rapid chondro lytic effect of pus within the joint, pyogenic septic arthritis of the hip in children represents a surgical emergency. It can be difficult to distinguish a septic hip from other causes of hip pain in children. In such cases, whilst clinical suspicion remains of paramount importance, Kochers diagnostic algorithm is a useful tool. The four diagnostic criteria are non-weight-bearing, ESR 40, WBC 12 and fever. The predicted risk of a septic arthritis varies with the number of positive criteria. The algorithm has been tested retrospectively and prospectively. In the prospective validation study the probabilities were lower:Number of criteria metChance of septic arthritis original studyChance of septic arthritis validation study139.52403539373499.693 