Scintigraphic evaluation of extremity pain in children: its efficacy and pitfalls.

Early detection of an inflammatory process involving bone and joints is very important in children with extremity pain. We reviewed the efficacy and pitfalls of three-phase bone scans in 100 consecutive children with acute extremity pain. Sixty-one of the subjects showed abnormalities on bone scans. The sensitivity and specificity of three-phase bone scans for acute osteomyelitis were 84% and 97%, respectively. Sensitivity and specificity for both acute septic joint and cellulitis were 93% and 100%, respectively. Pitfalls in interpretation of three-phase bone scans include simulation of infection by fracture and obscuration of osteomyelitis by septic arthritis, prior antibiotic treatment, and the occasional "cold" defect due to ischemia.