Clinical application of ultrasonography for detection of septic arthritis in children.

For early detection of the effusion of infected joint, 40 children were examined by ultrasound scanner for suspected septic arthritis. Thirty-one patients were found with joint effusion, and the needle aspirations of these 31 joints confirmed septic arthritis in 22 patients. In 3 patients, in addition to the joint effusion, the joint surrounding subperiosteal abscess and cortical erosion also were found on sonography, resulting in a diagnosis of concurrent osteomyelitis. In two patients, sonography confirmed only soft tissue swelling and abscess formation on the buttock, but without hip joint effusion. These findings excluded the diagnosis of septic arthritis and helped us obviate the unnecessary attempts at joint aspiration. In one patient, sonography revealed only flexor tenosynovitis without wrist joint effusion. This case was later treated by tenosynovectomy rather than wrist arthrotomy and the pathological examination showed to be a tuberculous tenosynovitis. From the preliminary results, we find ultrasonography has the following advantages for the diagnosis of septic arthritis: 1.) ultrasonography is very sensitive in detecting the joint effusion of septic arthritis; 2.) ultrasonography can clearly define the pathological extent of septic arthritis and help clinicians to treat the concurrent osteomyelitis by appropriate surgical debridement; and 3.) ultrasonography can differentiate soft tissue abscess or tenosynovitis from septic arthritis and help clinicians obviate unnecessary needle joint aspiration.