Hip radiography for the investigation of nontraumatic, short duration hip pain presenting to a children's emergency department.

OBJECTIVE: To assess the diagnostic accuracy of routine hip x-ray in 2- to 11-year-old children presenting to the emergency department with recent onset, nontraumatic hip pain and to assess the predictive value of other clinical presenting variables. METHODS: Retrospective chart review of children with hip pain of less than 2 weeks duration, presenting to a metropolitan children's emergency department in New Zealand. Data were extracted on radiography results, diagnosis on final discharge from hospital, and other clinical details. Diagnostic categories were divided into urgent pathology (those requiring immediate treatment) and nonurgent pathology (those requiring follow up and those requiring no treatment or follow up). Contingency analysis and logistic regression were performed on variables to assess ability to predict urgent pathology. RESULTS: Hip x-rays were performed in 99% of 310 eligible patients. Of these, 3% had some degree of significant abnormality reported on hip x-ray. Final diagnoses were transient synovitis in 86% of patients, osteomyelitis or other significant musculoskeletal sepsis in 8%, slipped upper femoral epiphysis in 1%, and other musculoskeletal disorder in 4%, with no cases of septic arthritis. In children 9 years or older, the likelihood ratio with a positive x-ray was 17, compared with 6 in children younger than 9 years. Fever, weight-bearing status, and age were the most important predictors of urgent pathology. CONCLUSIONS: In children younger than 9 years presenting with recent onset, nontraumatic hip pain, hip x-ray is of limited value. In children 9 years or older, hip x-ray may be useful to exclude slipped upper femoral epiphysis. Fever, weight bearing status, and age may better predict urgent pathology.

Managing children with acute non-traumatic limp: the utility of clinical findings, laboratory inflammatory markers and X-rays.

OBJECTIVES: To examine the utility of clinical findings, laboratory markers and X-ray radiographs (X-ray) in the assessment of children presenting with an acute non-traumatic limp. METHODS: A retrospective review of all children who received hip X-rays over a 2 year period in the Children's Emergency Department, Starship Children's Hospital, Auckland, New Zealand. Children were identified from the radiology database and clinical notes reviewed. Children aged 0-12 years old were included if the limp was acute (less than 2 weeks of duration) with no history of trauma. X-rays were reported by a consultant paediatric radiologist. Univariate and multivariate analysis was performed to determine predictors of osteomyelitis and septic arthritis. Receiver operator curves were used to assess the optimum cut-off points for C reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white cell count (WCC). RESULTS: A total of 350 patients were enrolled. There were 21 (6%) abnormal X-rays . Fever, non-weight bearing, raised white cell count, raised erythrocyte sedimentation rate and raised CRP were all associated with increased risk of septic hip or osteomyelitis. The optimum inflammatory marker cut-off was a CRP of 12 with a sensitivity of 87% and specificity of 91%. CONCLUSION: In acute non-traumatic limp, X-rays of the hips diagnose slipped upper femoral epiphysis, as such they should be routinely used from the age of 9 years upwards. Below this age they are of little value. Inflammatory markers have utility in risk-stratifying children and selecting a group in whom to proceed with definitive tests to exclude osteomyelitis or septic hip. Children with a short history and minimal symptoms can be managed with appropriate follow up and no investigations.