Alexander Nguyen BS, Presenter: Nothing to Disclose

J. Herman Kan MD, Abstract Co-Author: Nothing to Disclose

Scott B. Rosenfeld MD, Abstract Co-Author: Nothing to Disclose

George S. Bisset MD, Abstract Co-Author: Nothing to Disclose

The Kocher criteria are established clinical parameters that predict hip septic arthritis (SA) with a 93% or greater positive predictive value when 3 or 4 variables are present but the incidence of underlying osteomyelitis has not been reported. The purpose of this study is to evaluate the incidence of underlying osteomyelitis (OM) in patients who have 3 or 4 positive Kocher criteria.

77 consecutive patients (mean age 5.2 years) treated between 1/07 and 6/13 for suspected hip SA who had 3 or 4 positive Kocher criteria were retrospectively reviewed. The Kocher criteria variables include: nonweightbearing status, fever>38.5 C, WBC 12K, and ESR > 40 mm/hr. All patients underwent US and MRI as part of their work-up.

There were a total of 77 patients with 3 or 4 positive Kocher criteria. Of these, 37.7% (n=29) had a diagnosis of SA and 44.2% (n=44.2%) had a diagnosis of OM. Of the 77 patients, 56% (43/77) had a hip effusion by US. When an effusion was identified, 39.5% (17/43) had SA only and 37% (16/43) had OM. When no effusion was identified, 18/34 (51%) had underlying OM.  

Patients with 3 or 4 Kocher criteria have a high incidence (44%) of underlying osteomyelitis. Our results suggest that the combination of Kocher criteria and US results is not sufficient to make a diagnosis in patients presenting with hip irritability.

Patients with hip pain and 3 or 4 Kocher criteria should all routinely undergo MRI during work-up for suspected septic arthritis.

Nguyen, A, Kan, J, Rosenfeld, S, Bisset, G, Kocher Criteria Revisited in the Era of MRI: How Often Does the Kocher Criteria Identify Underlying Osteomyelitis?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018456.html