Initial Oral Antibiotics for Bone and Joint Infections in Children

Background: Initial oral antibiotic treatment for children and adolescents with uncomplicated BJI has been found non-inferior to initial IV antibiotics in one randomized controlled trial (RCT) from Denmark. The real-world effectiveness of initial oral antibiotics for children and adolescents with BJI is unclear. In Denmark, initial oral antibiotics were allowed in nationwide guidelines for children and adolescents aged 3 months to 17 years with uncomplicated BJI from 2024. Aim: We aim to compare the effectiveness and safety of initial oral antibiotics for children and adolescents with uncomplicated BJI in a real-world setting with those who received initial oral antibiotics in our RCT. Study design: Nationwide, prospective, multicenter, real-world cohort study. Patients: 100 children and adolescents aged 3 months to 17 years with uncomplicated BJI treated with initial oral antibiotics at one of the 18 Pediatric Departments in Denmark from 2024 to 2026. Uncomplicated BJI is defined by the absence of impaired general condition or signs of sepsis, rapidly progressing or severe symptoms, pronounced soft tissue involvement, prosthetic material, resistant pathogens, and severe comorbidities. Patients who have received intravenous antibiotic therapy for less than 24 h before oral antibiotics will be included. Control patients are 98 patients who received initial oral antibiotics for uncomplicated BJI as part of a Danish RCT conducted between 2020 and 2023. Methods: All children and adolescents treated for BJI will be prospectively enrolled. Designated co-investigators in the 18 Danish pediatric departments will ensure prospective, national inclusion. Follow-up assessments will be conducted after three, six, 12 month. The three-month follow-up will include a clinical examination to ensure full recovery. The six and 12-month follow-up will be conducted via a structured telephone interview and/or a clinical evaluation. All study data will be securely collected and managed in an online database. Outcomes: The primary outcome is sequelae after 6 months, defined as any atypical mobility or function of the affected bone or joint. Secondary outcomes are suspicion of treatment failure within 28 days, full recovery after initiation of treatment, recurrent infection within 6 months, and sequelae after 12 months and 5 years. Safety outcomes are surgical intervention and severe complications during antibiotic treatment. We will calculate the risk difference sequelae between the real-world and RCT cohorts using exact unconditional two-sided 95% confidence interval.