JBJS - 2026-05-05 - Journal Article
The Prevalence of Pediatric Septic Arthritis of the Hip with Concomitant Osteomyelitis: A Retrospective Study of 58 Consecutive Cases Investigated Using MRI.
Khan AA, Paris E, Sbampato V, De Marco G, Tabard-Fougère A, Vazquez O, Steiger C, Dayer R, Ceroni D
Topics
Key Takeaway
Systematic MRI identified concomitant osteomyelitis in 43% of pediatric septic hip cases, compared to only 16% detection by radiograph, yet osteomyelitis presence did not worsen outcomes.
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Summary
This retrospective study of 58 children with septic arthritis of the hip (2000–2025) used systematic MRI to determine the prevalence of concomitant osteomyelitis and its effect on outcomes. MRI identified osteomyelitis in 43% of cases versus 16% by plain radiograph, with no statistically significant differences in complications, treatment duration, or outcomes between isolated SA and SA-plus-osteomyelitis groups. Kingella kingae was the predominant pathogen (37.9%), while S. aureus and Streptococcus spp. were disproportionately associated with repeat surgery.
Key Limitation
The 25-year study window spans significant evolution in MRI protocols, antibiotic stewardship, and pathogen epidemiology, making it difficult to attribute outcome equivalence to any consistent management strategy.
Original Abstract
BACKGROUND
This observational study systematically used magnetic resonance imaging (MRI) to determine the prevalence of concomitant osteomyelitis and its influence on clinical outcomes in cases of pediatric septic arthritis (SA) of the hip.
METHODS
We retrospectively analyzed the demographic, clinical, microbiological, and radiographic data of 58 children treated for SA of the hip who underwent systematic MRI between 2000 and 2025. Patients were categorized into 2 groups: isolated septic arthritis and septic arthritis with concomitant osteomyelitis. The clinical and laboratory parameters, causative pathogens, and treatments were compared between the groups.
RESULTS
Concomitant osteomyelitis was identified with MRI in 43% (25) of the 58 patients, while radiographs detected it in only 16%. Demographic, clinical, and inflammatory parameters were statistically similar between the groups. Kingella kingae was the most commonly identified pathogen (37.9%), and Staphylococcus aureus and Streptococcus spp. were more frequently associated with repeat surgery. No significant differences in complication rates, treatment duration, or outcomes were found between the groups.
CONCLUSIONS
The systematic use of MRI revealed concomitant osteomyelitis in >40% of cases of pediatric SA. However, the presence of osteomyelitis was not associated with worse outcomes, suggesting that factors related to the microorganism profile or virulence must contribute substantially to disease severity. Nonetheless, MRI should be considered early in any diagnostic work-up of pediatric SA of the hip.
LEVEL OF EVIDENCE
Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.