Approach to hip pain

A 70-year-old male presents with insidious onset of anterior hip pain that limits his range of motion and causes a notable limp. His medical history includes hypertension and a recent diagnosis of sickle cell disease. Which of the following is the most likely cause of his hip pain?

1: Iliopsoas bursitis
2: Femoroacetabular impingement (FAI)
3: Avascular necrosis of the femoral head
4: Greater trochanteric pain syndrome