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.