Signs of Sacroiliac Joint Infection in Children
A review of 15 children with sacroiliac (SI) joint infection shows that early imaging studies don't confirm the diagnosis. In the first week of symptoms, the physician must rely on clinical and laboratory findings.
Common early symptoms of this condition include fever and tenderness over the SI joint. Most of the children in this study also had a positive Patrick's or FABER test. This is a painful response to moving the hip into a position of flexion (F), abduction (AB), and external rotation (ER). Other symptoms can include hip, buttock, or abdominal pain.
Early diagnosis is important to prevent serious problems. The diagnosis can be delayed when physical findings are vague and imaging studies are negative. Lab tests for white blood count (WBC), sed rate (ESR) and C-reactive protein (CRP) are needed to identify infection as the cause of the symptoms. The type of infection (staph or strep) is also determined.
Although X-rays are often negative, MRIs and bone scans almost always show some changes after six days. Once identified as an infection, antibiotics are the first step in treatment. Caught early enough, recurrence of SI joint infection and the need for surgery can be avoided.
Mark Grippi, MD, et al. The Early Diagnosis of Sacroiliac Joint Infections in Children. In Journal of Pediatric Orthopaedics. September/October 2006. Vol. 26. No. 5. Pp. 589-593.