Septic arthritis of facet joint incidence in children higher than expected

Incidence of septic arthritis of the facet joint (SAFJ) in children is much higher than seen in literature, with half of the cases complicated by an epidural infection, reveals a study.

“Simple clinical symptoms detected as early as the bedside allow a strong suspicion of SAFJ, justifying the use of a first-line magnetic resonance imaging (MRI) to confirm the diagnosis and precisely describe the extension,” the authors said.

The study sought to estimate the incidence rate of SAFJ in children, specify SAFJ clinical, imaging, and laboratory findings, and identify avenues for appropriate management. The authors carried out a 10-year consecutive SAFJ case series using their imaging centre database combined with a 50-year systematic review of literature cases.

The mean incidence of paediatric SAFJ was 0.23±0.4 per 100,000 children-years. Key symptoms were as follows: potty refusal (in toddlers) or painful sitting (78 percent) and lateralized signs (paravertebral tenderness and/or swelling (88 percent). MRI was used to obtain SAFJ diagnosis and extension (94 percent); epidural extension was found in eight of 16 cases.

Antibiotic treatment lasted for a mean of 5.1 weeks. The compliance with guidelines was 79 percent for empiric and 62 percent for targeted antibiotic therapies.

“Focusing on simple clinical signs is key to justify the transfer of a child or the shortening of the delay to obtain an MRI,” the authors said. “However, as MRI availability increases in most Western countries, and the capacity for diagnosis increases, the awareness of SAFJ must be spread to avoid missed cases.”