Community-acquired bone and joint infections in children: a 1-year prospective epidemiological study.

BACKGROUND: The incidence of childhood bone and joint infections (BJIs) is not well known, but is useful for identifying epidemiological differences and improving practice. OBJECTIVE: To determine the incidence of BJI in previously well children and describe their clinical, laboratory and radiological characteristics. DESIGN: A multicentre, population-based, prospective study performed from July 2008 through June 2009. SETTING: Region of northern France with a population of 872 516 children <16 years old. PATIENTS: All previously well children admitted in the region with septic arthritis, acute osteomyelitis or spondylodiscitis, diagnosed according to consensus criteria and after blinded radiological review. MAIN OUTCOME MEASURES: The corrected incidence of BJI, determined with a capture-recapture method that used this prospective database and the discharge summary database. RESULTS: 58 cases were identified (median age: 3.6 years, range: 1 month-15.8 years; male to female ratio: 1.6). The completeness of the prospective database was 90%. The corrected incidence of any BJI was 7.1/100 000 children (95% CI 5.3 to 8.9). Thirty patients had septic arthritis (52%, incidence: 3.7/100 000; 95% CI 2.4 to 4.9), 24 osteomyelitis (41%, incidence 3.0/100 000; 95% CI 1.8 to 4.1), 4 spondylodiscitis (7%) and 0 osteoarthritis. Micro-organisms were identified from 15 patients (26%), with Staphylococcus aureus the most frequent organism. Radiological findings were characteristic of infection in 44% of BJI. CONCLUSIONS: The corrected incidence of BJI in northern France, according to consensus diagnostic criteria, was 7.1/100 000 children <16 years of age.

Prevalence and clinical significance of occult fractures in children with radiograph-negative acute ankle injury. A meta-analysis.

BACKGROUND AND PURPOSE: Plain radiographs may fail to reveal an ankle fracture in children because of developmental and anatomical characteristics. In this systematic review and meta- analysis, we estimated the prevalence of occult fractures in children with acute ankle injuries and clinical suspicion of fracture, and assessed the diagnostic accuracy of ultrasound (US) in the detection of occult fractures. METHODS: We searched the literature and included studies reporting the prevalence of occult fractures in children with acute ankle injuries and clinical suspicion of fracture. Proportion meta-analysis was performed to calculate the pooled prevalence of occult fractures. For each individual study exploring the US diagnostic accuracy, we calculated US operating characteristics. RESULTS: 9 studies (involving 187 patients) using magnetic resonance imaging (MRI) (n = 5) or late radiographs (n = 4) as reference standard were included, 2 of which also assessed the diagnostic accuracy of US. Out of the 187 children, 41 were found to have an occult fracture. The pooled prevalence of occult fractures was 24% (95% CI: 18-31). The operating characteristics for detection of occult ankle fractures by US ranged in positive likelihood ratio (LR) from 9 to 20, and in negative LR from 0.04 to 0.08. INTERPRETATION: A substantial proportion of fractures may be overlooked on plain radiographs in children with acute ankle injuries and clinical suspicion of fracture. US appears to be a promising method for detection of ankle fractures in such children when plain radiographs are negative.