A 7 yr. old boy with abrupt onset of pain in hip with hip held in abduction. Hemogram is normal. ESR is raised. What is the next line of management-

The Flexion, Abduction, and External Rotation (FABER) test to detect hip problems. 1st investigation of choice is USG HIP FOR ANY HIP DISPLACEMENTS The test is performed by having the patient lie in a supine position, placing the foot of the affected side on the opposite knee; groin pain indicates a hip problem rather than a spinal problem. The physician then presses firmly on the flexed knee and on the opposite anterior superior iliac crest; pain in the sacroiliac area indicates a problem with sacroiliac joints. REF : MAHESWARI 9TH ED