Clinical Characteristics and Outcomes of Culture-positive Versus Culture-negative Bone and Joint Infections in Pediatric Patients: A 10-Year Multicenter Study From Hungary

BACKGROUND: Despite advancements, a proportion of pediatric bone and joint infections remain culture negative, complicating diagnosis and therapy. This study aimed to compare characteristics and outcomes of culture-negative versus culture-positive infections in a pediatric cohort over a 10-year period. METHODS: A retrospective, multicenter observational study was conducted across 6 tertiary care centers in Hungary between 2015 and 2024, including hospitalized children with primary hematogenous osteomyelitis or septic arthritis within 2 months of symptom onset. The primary outcome was the requirement for surgical intervention within 30 days of diagnosis; secondary outcomes included the incidence of short-term (at 30 days) and long-term complications (at follow-up end). Postdischarge follow-up continued until the last documented hospitalization or outpatient visit. RESULTS: Ninety-seven patients were included. Osteomyelitis, arthritis and combined infection were diagnosed in 49.5%, 28.9% and 21.6% of cases, respectively. A pathogen was identified in 72.5% of patients, most frequently via intraoperative cultures (74.2%) and blood cultures (53.6%). Staphylococcus aureus was the predominant pathogen (71.2%), followed by Streptococcus pyogenes (11.9%) and Salmonella spp. (6.8%). Within 30 days of diagnosis, the culture-positive group exhibited a significantly higher rate of surgical intervention, compared to the culture-negative group (79.7% vs. 34.2%, P = 0.001). Short-term complications were also more frequent in culture-positive cases (64.4% vs. 42.1%, P = 0.031). No difference was observed in long-term complication rates between groups. CONCLUSIONS: In pediatric patients, culture-positive bone and joint infections are associated with a more severe short-term clinical course and an increased likelihood of surgical intervention, particularly when S. aureus is the causative agent.