A 7 year 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?

Synol fluid analysis allows most effusions to be classified as normal, inflammatory, non- inflammatory, infectious, or hemorrhagic. Each type of effusion suggests ceain joint diseases. So-called non-inflammatory effusions are actually mildly inflammatory but tend to suggest diseases with less inflammatory mechanisms. If infection is suspected, a poion of the synol fluid sample should be sent to the laboratory for Gram stain and culture. Synol fluid analysis provides a definitive diagnosis for infections and crystal ahropathies that rarely affect hip joints. Ref: Gurkan I., Mears S. (2007). Chapter 11. The Patient with Hip Pain. In J.B. Imboden, D.B. Hellmann, J.H. Stone (Eds), CURRENT Rheumatology Diagnosis & Treatment, 2e.