A 40-year-old woman comes to the office due to pain in her right hip for the past 4 weeks. The pain increases with weight bearing. She has no morning stiffness, warmth, or erythema, and no pain in other joints. The patient has no history of significant trauma to the hip and has not had similar pain before. She was diagnosed with systemic lupus erythematosus 7 years ago. Her current medications include low-dose prednisone, hydroxychloroquine, and lansoprazole. The patient does not use tobacco, alcohol, or illicit drugs. She is afebrile, and vital signs are normal. There is no local tenderness over any joints, and range of motion of the right hip is normal. Plain film radiograph of the hip is normal. Which of the following is the best next step in management of this patient?

Question

A 40-year-old woman comes to the office due to pain in her right hip for the past 4 weeks.  The pain increases with weight bearing.  She has no morning stiffness, warmth, or erythema, and no pain in other joints.  The patient has no history of significant trauma to the hip and has not had similar pain before.  She was diagnosed with systemic lupus erythematosus 7 years ago.  Her current medications include low-dose prednisone, hydroxychloroquine, and lansoprazole.  The patient does not use tobacco, alcohol, or illicit drugs.  She is afebrile, and vital signs are normal.  There is no local tenderness over any joints, and range of motion of the right hip is normal.  Plain film radiograph of the hip is normal.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d510_fd0a_bc81_5906f93c70ca_MD0003_00 This patient with systemic lupus erythematosus (SLE), who is on prednisone, has atraumatic hip pain with normal x-ray findings, most likely due to osteonecrosis (avascular necrosis) of the femoral head. Osteonecrosis can occur in disorders that disrupt the circulation of bone through micro-occlusion, abnormal endothelial function, or increased intra-osseus pressure. It is a common complication of SLE, and the risk is greatly increased in patients treated with glucocorticoids. Osteonecrosis of the femoral head is characterized by pain in the groin, thigh, or buttock that is worsened by activity. Early examination findings may be normal, but progression of the disease can lead to reduced range of motion (particularly internal rotation and abduction) and joint instability. In the first few months, x-rays also will often be normal, and MRI is a more sensitive test. MRI can visualize the boundary between normal and ischemic bone, as well as the zone of hypervascularity. In advanced disease, plain x-rays may show subchondral lucency (crescent sign) and deformities of the femoral head. MRI subchondral lucency (Choice A) Bone densitometry is used to diagnose osteopenia or osteoporosis. In patients with decreased bone density, subchondral fracture of the femoral head is occasionally seen and would be visible on MRI (bone densitometry would not be diagnostic). (Choice B) An uncontrolled flare of SLE (requiring increased doses of prednisone) would rarely present as isolated hip pain. Typical manifestations include rash, fever, mucocutaneous ulcers, or polyarticular synovitis. Noninflammatory pain localized to the hip is more consistent with osteonecrosis. (Choice C) Arthrocentesis is indicated to evaluate septic or crystal-induced arthritis (eg, gout). These conditions would cause an acute inflammatory arthritis with decreased range of motion. In addition, septic arthritis would cause fever and other systemic symptoms, whereas gout only rarely affects the hip. (Choice E) Nonsteroidal anti-inflammatory drugs are often used in association with reduced weight bearing in the symptomatic management of osteonecrosis. However, an MRI should be performed in this patient to exclude other causes of hip pain, confirm the diagnosis of osteonecrosis, and help in determining management (which sometimes includes operative interventions). Educational objective: Osteonecrosis is a common complication of systemic lupus erythematosus, and the risk is increased with chronic glucocorticoid use. It causes pain in the groin, thigh, or buttock that is worsened by activity. Early examination findings and x-rays may be normal, and MRI is a more sensitive test.

A 40-Year-Old Woman Comes to the Office Due to Pain