MRI Hip — Femoral Head AVN

A 45-year-old man on long-term corticosteroids for systemic lupus erythematosus presents with groin pain and limited hip abduction. Plain radiographs of the hip are normal. MRI shows a characteristic double-line sign in the structure marked **A** with an inner high T2 signal band surrounded by a low T2 signal sclerotic band. What is the most appropriate next management step for this patient?

A 45-year-old man on chronic corticosteroid therapy for systemic lupus erythematosus presents with progressive left hip pain and limited internal rotation. MRI of the hip is performed. The structure marked **A** in the diagram shows a characteristic double-line sign on T2-weighted imaging — an inner high-signal reactive band surrounded by an outer low-signal sclerotic band. X-ray radiographs of the same hip appear normal. What is the most likely diagnosis?