Characteristics and outcome of septic arthritis in children.

BACKGROUND AND PURPOSE: To assess the etiologic agents, presentation, laboratory findings, treatment, clinical outcome and prognostic factors of pyogenic arthritis in pediatric patients.

METHODS: We reviewed the medical records of patients under 18 years of age with a diagnosis of septic arthritis from January 1971 to July 2004. Information collected included clinical characteristics, laboratory data, response to therapy and outcome. An unsatisfactory clinical outcome was defined as the development of sequelae including ambulatory disability, limb-length discrepancy, chronic osteomyelitis, and abnormalities of bone growth.

RESULTS: A total of 60 children who met the criteria for diagnosis of septic arthritis were included. The etiologic agent was identified in 71.7% of the patients. Staphylococcus aureus was the most common etiologic agent in all age groups (59.0%). The erythrocyte sedimentation rate was higher than 20 mm/h in 89% of patients and soft tissue swelling was the most common radiographic finding (16.7%). Lower extremity involvement was found in 90.8% of patients and the knee joint was most commonly involved. The clinical outcome was unsatisfactory in 28.3% of patients. The duration of symptoms before the initiation of treatment was significantly longer in patients with sequelae (4.2 vs 13.1 days, p<0.01), and the neutrophil percentage in peripheral blood was also significantly higher in this group (81.5% vs 65.7%, p=0.027).

CONCLUSIONS: Delayed treatment and increased neutrophil ratio in peripheral blood were significantly associated with an increased risk of sequelae.