title: Transient synovitis of the hip: which investigations are truly useful?
abstract: OBJECTIVE
  To assess the usefulness of several laboratory and radiological investigations for the limping child with suspected transient synovitis of the hip.
  
  
  METHODS
  The medical records of children admitted at our children's hospital for nontraumatic hip pain between 1999 and 2007 were retrospectively reviewed. During the study period, all children without a definite diagnosis after routine investigations in the emergency department were admitted and a specific work-up including antinuclear antibodies titre, rheumatoid factor, antistreptolysin O titre, Lyme disease serology and hip ultrasonography were obtained. Children were systematically re-evaluated 6 weeks after hospital discharge, with a clinical examination and radiological hip views. Patients were diagnosed with transient synovitis of the hip if an ultrasound-confirmed hip effusion was present at time of admission, complete resolution of symptoms occurred without any specific treatment, and no other pathology of the hip was identified during follow-up.
  
  
  RESULTS
  A total of 417 cases without definite diagnosis were admitted and were submitted to a specific work-up. Transient synovitis of the hip was subsequently diagnosed in 383 patients, septic arthritis in 1 patient, and Lyme arthritis in 1 patient. Thirty-two patients remained without diagnosis. No rheumatological condition was found.
  
  
  CONCLUSIONS
  Our results suggest that most investigations performed during the initial work-up in patients suspected transient synovitis of the hip are unnecessary and should routinely include only white blood cell count, C-reactive protein, erythrocyte sedimentation rate, and hip radiography and ultrasonography. No further investigations are necessary during follow-up for transient synovitis of the hip in asymptomatic children.
authors: Paediatric Orthopaedic Division, University Hospitals of Geneva, Switzerland.
authors: Victor
authors: V
authors: Dubois-Ferrière
authors: Paediatric Orthopaedic Division, University Hospitals of Geneva, Switzerland.
authors: Wilson
authors: W
authors: Belaieff
authors: Paediatric Orthopaedic Division, University Hospitals of Geneva, Switzerland.
authors: Pierre
authors: P
authors: Lascombes
authors: Paediatric Orthopaedic Division, University Hospitals of Geneva, Switzerland.
authors: Geraldo
authors: G
authors: de Coulon
authors: Paediatric Orthopaedic Division, University Hospitals of Geneva, Switzerland.
authors: Dimitri
authors: D
authors: Ceroni
mesh_terms: D000465:Algorithms; D001799:Blood Sedimentation; D002097:C-Reactive Protein; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006615:Hip / Q000000981:diagnostic imaging*; D006776:Hospitals, Pediatric / Q000458:organization & administration; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D010146:Pain / Q000209:etiology*; D011859:Radiography; D012189:Retrospective Studies; D013585:Synovitis / Q000097:blood / Q000175:diagnosis*; D014463:Ultrasonography
chemical_list: D002097:C-Reactive Protein