title: Differentiating Kingella kingae septic arthritis of the hip from transient synovitis in young children.
abstract: OBJECTIVE
  To conduct a retrospective multicenter study to assess the ability of a predictive algorithm to differentiate between children with Kingella kingae infection of the hip and those with transient synovitis.
  
  
  METHODS
  Medical charts of 25 Israeli and 9 Spanish children aged 6-27 months with culture-proven K kingae arthritis of the hip were reviewed, and information on the 4 variables included in the commonly used Kocher prediction algorithm (body temperature, refusal to bear weight, leukocytosis, and erythrocyte sedimentation rate) was gathered.
  
  
  RESULTS
  Patients with K kingae arthritis usually presented with mildly abnormal clinical picture and normal serum levels of or near-normal acute-phase reactants. Data on all 4 variables were available for 28 (82%) children, of whom 1 child had none, 6 children had 1, 13 children had 2, 5 had 3, and only 3 children had 4 predictors, implying ≤ 40% probability of infectious arthritis in 20 (71%) children.
  
  
  CONCLUSIONS
  Because of the overlapping features of K kingae arthritis of the hip and transient synovitis in children younger than 3 years of age, Kocher predictive algorithm is not sensitive enough for differentiating between these 2 conditions. To exclude K kingae arthritis, blood cultures and nucleic acid amplification assay should be performed in young children presenting with irritation of the hip, even in the absence of fever, leukocytosis, or a high Kocher score.
authors.affiliation: Clinical Microbiology Laboratory, Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Pablo
authors.initials: P
authors.lastname: Yagupsky
authors.affiliation: Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Dubnov-Raz
authors.affiliation: Molecular Microbiology Department, University Hospital Sant Joan de Deu, Barcelona, Spain.
authors.forename: Amadeu
authors.initials: A
authors.lastname: Gené
authors.affiliation: Pediatric Infectious Diseases Unit, Carmel Medical Center, and the Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Ephros
mesh_terms: D000465:Algorithms; D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000382:microbiology; D001799:Blood Sedimentation; D001831:Body Temperature; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006621:Hip Joint / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D007223:Infant; D017882:Kingella kingae / Q000302:isolation & purification*; D007958:Leukocyte Count; D008297:Male; D016870:Neisseriaceae Infections / Q000175:diagnosis* / Q000382:microbiology; D011336:Probability; D012189:Retrospective Studies; D013585:Synovitis / Q000175:diagnosis* / Q000382:microbiology