Pediatric hip pain: Transient synovitis versus septic arthritis

Although there are many causes of an irritable hip in children, transient synovitis and septic arthritis are the two most common etiologies. Both present with inability or difficulty to bear weight on the affected leg, pain, stiffness, limp, and fluid within the synovium. Because of potential serious complications associated with septic arthritis, accurate and early differentiation between the two processes is important. The workup for pediatric hip pain includes a thorough history and physical examination, appropriate laboratory studies, pelvis/hip radiography, hip sonography, and possible arthrocentesis.