A 70-year-old woman presents to your office for evaluation of arthritis in the right hip. She has had arthritis for 5 years, as well as progressive pain on weight-bearing and limitation of ambulation. A recent hip radiograph showed marked joint space narrowing, marginal osteophytes, and subchondral cysts. Compared with radiographs 1 year ago, the changes are somewhat more advanced. During the last 2 months, she has also experienced a dull aching pain in the right hip at night that interferes with her sleep. This differs from her previous hip pain and is unrelieved by an increase in the dose of naproxen to 500 mg twice daily. She has been afebrile, and her general health has been good. Recent routine laboratory studies, including a complete blood count, are normal. On physical examination, the right hip has 30 degrees of flexion contracture and l0 degrees of total rotation. There is marked pain on motion. What would you do next? (A) Order MRI of right hip. (B) Order CT of abdomen and pelvis. (C) Refer to rheumatologist for further medical management. (D) Refer to invasive radiologist for fluoroscopic aspiration of synovial fluid from hip. (E) Refer to orthopedic surgeon for total hip replacement.