Abstract: We included two RCTs involving a total of 149 children between three months and 18 years of age who were receiving antibiotics for septic arthritis. The most commonly affected joints were hips and knees. These studies were performed in Costa Rica and Israel. In both studies, dexamethasone administered intravenously (ranging from 0.15 to 0.2 mg/kg/dose every six to eight hours) during four days was the corticosteroid, and the comparator was placebo. Trials excluded patients with any degree of immunodeficiency or immunosuppression. The longest follow-up was one year. Trials did not report activities of daily living nor length of hospital stay. Both studies used adequate processes for randomisation, allocation concealment, and blinding, and review authors judged them to have low risk of selection and performance bias. Losses to follow-up were substantive in both studies, and we judged them to have high risk of attrition bias and of selective outcome reporting. We graded all outcomes as low quality due to concerns about study limitations and imprecision. The risk ratio (RR) for absence of pain at 12 months of follow-up was 1.33, favouring corticosteroids (95% confidence interval (CI) 1.03 to 1.72; P = 0.03; number needed to treat for an additional beneficial outcome (NNTB) = 13, 95% CI 6 to 139; absolute risk difference 24%, 95% CI 5% to 43%). The RR for normal function of the affected joint at 12 months of follow-up was 1.32, favouring corticosteroids (95% CI 1.12 to 1.57; P = 0.001; NNTB = 13, 95% CI 7 to 33; absolute risk difference 24%, 95% CI 11% to 37%). We found a reduction in the number of days of intravenous antibiotic treatment favouring corticosteroids (mean difference (MD) -2.77, 95% CI -4.16 to -1.39) based on two trials with 149 participants. Researchers did not report length of hospital stay. One trial (49 participants) reported that treatment with dexamethasone was associated with a shorter duration of IV antibiotic treatment, leading to a shorter hospital stay, and although duration of hospitalisation was a primary outcome of the study, study authors did not provide data on the duration of hospitalisation. We downgraded the quality by one level for concerns about study limitations (high risk of attrition bias and selective reporting), and by another level for imprecision. In one trial of 49 participants, researchers followed 29 children for 12 months, and parents reported that no children demonstrated adverse effects of the intervention. Evidence for corticosteroids as adjunctive therapy in children with a diagnosis of septic arthritis is of low quality and is derived from the findings of two trials (N = 149). Corticosteroids may increase the proportion of patients without pain and the proportion of patients with normal function of the affected joint at 12 months, and may also reduce the number of days of antibiotic treatment. However, we cannot draw strong conclusions based upon these trial results. Additional randomised clinical trials in children with relevant outcomes are needed.

Plain-language summary: Researchers conducted a review of the effects of corticosteroids given in addition to antibiotics to children with septic arthritis. Evidence was sought until April 2018. After searching for all relevant studies, reviewers found two studies with 149 children. These studies were conducted in hospitalised children with a normal immune system between the ages of three months and 18 years living in Costa Rica and Israel. The longest follow-up was one year. Reviewer findings are summarised below. What is septic arthritis and what are corticosteroids?  Septic arthritis, which is more frequent in children, is a serious disease caused by bacteria that infect the joints. Patients are usually treated with antibiotics, but secondary inflammation can destroy the joint and can reduce the ability of the joint to function normally. Corticosteroids are a group of medications with anti-inflammatory properties. Corticosteroids may reduce the consequences of inflammation in the joints. For children with septic arthritis who are taking antibiotics compared to placebo (fake medication) 1. Corticosteroids may reduce pain in affected joints at one year of follow-up 2. Corticosteroids may improve normal function of affected joints at one year of follow-up 3. Corticosteroids may reduce days of intravenous antibiotic treatment needed 4. Corticosteroids may have little or no effect on total or serious adverse effects We do not have information about the effects of corticosteroids on activities of daily living. What happens to children with septic arthritis who take corticosteroids in addition to antibiotics? Absence of pain 1. 24 more of 100 children experienced absence of pain after 12 months with corticosteroids (24% absolute improvement) 2. 96 of 100 children experienced absence of pain compared to 72 of 100 children who took a placebo Activities of daily living Included studies did not report this outcome. Normal physical joint function 1. 24 more of 100 children who received corticosteroids had normal function of the joint after 12 months (24% absolute improvement) 2. 98 of 100 children experienced absence of pain compared to 74 of 100 children who received a placebo Number of days of intravenous antibiotic treatment 1. Children who received corticosteroids compared with placebo had 2.77 fewer days of intravenous antibiotic treatment 2. Children who received corticosteroids had 8.09 days of intravenous antibiotic treatment 3. Children who received placebo had 10.86 days of intravenous antibiotic treatment Length of hospital stay 1. We are uncertain whether corticosteroids had an effect on the length of hospital stay because the evidence was of very low quality Total or serious adverse events 1. None of the patients treated with corticosteroids reported adverse effects at 12 months Quality of the evidence Overall, these studies provided low-quality evidence due to small numbers of study participants and concerns about study design. Evidence on length of hospital stay was of very low quality, as this was not clearly reported.