A 58-year-old man from Mumbai presents with a 2-year history of progressive pain and swelling in his right hip. He reports pain radiating to the groin and anterior thigh, which worsens with walking and internal rotation of the hip. On examination, there is restricted internal rotation and extension of the right hip. He has a positive FABER test. His ESR is 18 mm/hr and CRP is 2 mg/L. X-ray of the pelvis shows joint space narrowing, osteophytes around the femoral head and acetabulum, and subchondral cyst formation. What is the most appropriate first-line management?