Comparison of bacteriologically proven septic arthritis of the hip and knee in children, a preliminary study.

The hip and knee are the commonest joints affected by septic arthritis in the pediatric age group. Both can present as a limping, unwell child and can be difficult to diagnose. The primary aim of this study is to review and compare characteristics of pediatric patients with culture positive septic arthritis of the hip to those with culture positive septic arthritis of the knee. We retrospectively reviewed all patients who were clinically diagnosed with acute septic arthritis of either hip or knee in a tertiary pediatric hospital for a period of 3 years. Twelve of 29 patients who underwent arthrotomy for presumed septic arthritis of the hip and 7 of 37 patients who underwent arthrotomy for presumed septic arthritis of the knee had positive joint cultures. Patients with septic arthritis of the knee were much younger than that with septic arthritis of the hip. Patients with presumed septic arthritis of the knee based on clinical picture were less likely to have a positive synovial fluid culture. Children with septic arthritis of the knee did not follow Kocher criteria in the same way that children with septic arthritis of the hip did.