Ultrasonography of the painful hip. Prospective studies in 204 patients.

A total number of 204 patients presenting with an acutely or subacutely painful hip joint were investigated in two prospective studies. Intraarticular fluid collections were detected in 104 patients. The joint effusions showed different echopatterns depending on etiology and duration of disease. Additional diagnostic criteria such as synovial hypertrophy and thickening of the articular capsule allowed the distinction between transient synovitis and septic arthritis. Bony changes were encountered in 40 patients with osteomyelitis, slipping femoral epiphysis or Perthes-Calvé disease. Ultrasonography is recommended as method of choice in detecting, excluding and differentiating of joint effusions.