A 38-year-old man comes to the office with a 6-week history of progressive right hip pain. He localizes the pain to the right groin and says that it is present at rest and worse with weight bearing. The patient has no history of trauma and has not had similar symptoms before. Medical history is notable for sarcoidosis, which has required extended courses of oral glucocorticoids. His temperature is 37.2 C (98.9 F) and blood pressure is 156/86 mm Hg. On examination, the patient's face is round and there is fullness in the supraclavicular area. Forced abduction and internal rotation of the femur aggravate the pain. Muscle power is slightly decreased in the proximal thigh muscles in both legs. Reflexes are 2+ throughout, and there are no sensory deficits. Plain films of the right hip show no significant abnormalities. Which of the following is the most likely cause of this patient's hip pain?

Question

A 38-year-old man comes to the office with a 6-week history of progressive right hip pain.  He localizes the pain to the right groin and says that it is present at rest and worse with weight bearing.  The patient has no history of trauma and has not had similar symptoms before.  Medical history is notable for sarcoidosis, which has required extended courses of oral glucocorticoids.  His temperature is 37.2 C (98.9 F) and blood pressure is 156/86 mm Hg.  On examination, the patient's face is round and there is fullness in the supraclavicular area.  Forced abduction and internal rotation of the femur aggravate the pain.  Muscle power is slightly decreased in the proximal thigh muscles in both legs.  Reflexes are 2+ throughout, and there are no sensory deficits.  Plain films of the right hip show no significant abnormalities.  Which of the following is the most likely cause of this patient's hip pain?

Quizplus · Accepted Answer

11ec25c8_d970_390a_bc81_81b278de37f9_MD0003_00 This patient with progressive hip pain in the setting of chronic glucocorticoid use (dorsocervical fat pad, moon facies, glucocorticoid myopathy) has typical features of osteonecrosis (avascular necrosis) of the femoral head. Osteonecrosis occurs in disorders that disrupt the circulation of bone through micro-occlusion, abnormal endothelial function, or increased intraosseous pressure. It is a common complication of long-term glucocorticoid use, possibly due to effects on osteocytes or abnormal plasma lipid levels causing microemboli. Osteonecrosis causes bone and bone marrow infarction. Abnormal bone remodeling subsequently results in trabecular thinning and collapse over months to years. Osteonecrosis of the femoral head is characterized by pain in the groin, thigh, or buttock that is worsened by activity and relieved by rest. Progression of the disease can lead to reduced range of motion (usually abduction and internal rotation), rest pain, and joint instability. In the first few months, x-rays are often normal, and MRI is a more sensitive test. (Choice A) Septic arthritis can occur in the hip from hematogenous seeding or direct extension of a regional infection (eg, diverticulitis). Most patients have systemic symptoms (eg, fever) and an acute course over days. (Choice B) Osteoarthritis is characterized by degeneration of the articular cartilage, leading to pain with movement. Advanced disease can cause pain at rest but would likely be associated with x-ray findings. Osteoarthritis of the hip is uncommon in patients age <40 unless there is antecedent trauma or a systemic disorder that causes premature joint degeneration (eg, hemochromatosis). (Choice D) Trochanteric bursitis is caused by friction of the tendons of the gluteus medius and tensor fascia lata over the greater trochanter. Pain is localized to the lateral hip and is worsened by direct pressure. (Choice E) Gout is an inflammatory arthritis caused by deposition of monosodium urate crystals. It affects the metatarsophalangeal joints and knees much more often than the hips, usually causes recurrent attacks, and would be relieved by glucocorticoid use. Educational objective: Osteonecrosis (avascular necrosis) of the femoral head is a common complication of glucocorticoid use. It is characterized by progressive hip pain, leading to reduced range of motion and joint instability. X-rays will often be normal, and MRI is a more sensitive test. References: High-dose corticosteroid use and risk of hip osteonecrosis: meta-analysis and systematic literature review. (http://www.ncbi.nlm.nih.gov/pubmed/25900167)

A 38-Year-Old Man Comes to the Office with a 6-Week