CLINICAL HISTORY. — The parents brought this 2½-year-old boy to the Emergency Room of Childrens Hospital with the chief complaint of progressive inability to walk for the past three weeks. Prior to this, he had been in good health except for a mild upper respiratory infection. At the onset, it was felt this child was limping to imitate his cousin who did have a limp. However, the patient's symptoms progressed until he refused to walk, and had remained in bed during the past week. He also complained of progressive bilateral inguinal, suprapubic, thigh, and knee pain during the past two weeks. No other significant history was obtained.
Physical Examination.—The patient was a well-developed, well-nourished boy who would not stand, but was comfortable while lying down. He was afebrile. He kept his knees flexed and had considerable pain when his legs were fully extended. There was no muscle tenderness, and