A 31-year-old woman comes to the office due to a 4-month history of left hip and groin pain. She has a constant, dull, achy pain at rest that is exacerbated by movement of the hip or weight bearing. The patient has had no recent falls or other trauma. Medical history is significant for sickle cell disease, pneumococcal pneumonia, and acute chest syndrome. There is no redness, warmth, or tenderness over the hip joint, but decreased active and passive internal and external rotation, extension, and abduction are noted. Imaging of the hip is shown in the exhibit. Which of the following is the most likely cause of this patient's pain?

Question

A 31-year-old woman comes to the office due to a 4-month history of left hip and groin pain.  She has a constant, dull, achy pain at rest that is exacerbated by movement of the hip or weight bearing.  The patient has had no recent falls or other trauma.  Medical history is significant for sickle cell disease, pneumococcal pneumonia, and acute chest syndrome.  There is no redness, warmth, or tenderness over the hip joint, but decreased active and passive internal and external rotation, extension, and abduction are noted.  Imaging of the hip is shown in the exhibit.  Which of the following is the most likely cause of this patient's pain?

Quizplus · Accepted Answer

11ec160b_3a61_76ed_9249_51b37f37e8d1_MD0001_00 This patient has chronic hip pain that is worse with weight bearing and decreased range of motion in multiple axes. X-ray reveals flattening and patchy sclerosis of the femoral head consistent with osteonecrosis (avascular necrosis). Biopsy is not generally required for diagnosis, but microscopic analysis of the affected bone may show dead bony trabeculae (empty lacunae) and fat necrosis. Osteonecrosis occurs due to disruption of the macrovasculature or microvasculature of bone. The femoral head is the most common location, although other bones may be affected. Conditions associated with osteonecrosis include the following: Sickle cell disease can cause thrombotic occlusion of arteries. Embolic disorders (eg, fat emboli, decompression sickness) can directly occlude small arteries. High-dose systemic corticosteroids and excessive alcohol intake can cause fat embolism and adipocyte hypertrophy in the marrow. Vasculitis (eg, systemic lupus erythematosus) can injure the vessel wall, resulting in distal ischemia. Femoral neck fracture can disrupt the medial circumflex femoral artery, which is the main arterial supply for the femoral head. (Choice A) Achondroplasia is an autosomal dominant disorder characterized by severely restricted chondrocyte proliferation in growth plate cartilage and decreased endochondral ossification. The shortened limbs and other features of this disorder are usually apparent in childhood. (Choices B and E) The chronic joint destruction in rheumatoid arthritis (RA) is associated with the formation of synovial pannus, an invasive mass composed of fibroblast-like synovial cells, granulation tissue, and inflammatory cells. At the same time, the affected joints undergo a cytokine-mediated increase in bone resorption with loss of subchondral bone that is visible on x-ray as periarticular erosions. Although RA can affect the hip, it typically affects the small joints of the hand and wrist; hip monarthritis is rare. (Choice C) Ankylosing spondylitis (AS) is characterized by bony erosions with excessive bone regrowth driven by overproduction of cytokines (eg, IL-17, IL-22, TNF-alpha). AS can affect the hip, but most patients have chronic back and sacroiliac pain; large-joint monarthritis is rare. Educational objective: Osteonecrosis (avascular necrosis) occurs due to disruption of the macrovasculature or microvasculature of bone. The femoral head is the most common location. Sickle cell disease can cause osteonecrosis due to the thrombotic occlusion of arteries. Other major risk factors include embolic disorders, high-dose systemic corticosteroids, excessive alcohol use, vasculitis (eg, systemic lupus erythematosus), and femoral neck fracture. __________ References: Current concepts on osteonecrosis of the femoral head. (http://www.ncbi.nlm.nih.gov/pubmed/26396935)

A 31-Year-Old Woman Comes to the Office Due to a 4-Month