Review Question - QID 103302

This patient with sickle cell disease most likely has avascular necrosis (AVN) of the hip given his hip pain, cool/normal appearing joint, and restricted range of motion. The most appropriate initial step in management is a radiograph of the hip.

Avascular necrosis of the hip presents with hip pain and a restricted range of motion. It occurs secondary to interruption of the blood supply to the bone resulting in necrosis. Diagnosis of AVN of the hip can involve several imaging modalities. The most appropriate initial step in management is a plain film of the hip which can show necrosis and collapse of the femoral head. MRI is the most accurate test in uncertain cases. The treatment of AVN of the hip is generally casting and reduced weight bearing; however, severe/persistent cases may require orthopedic surgery.

Incorrect Answers:
Answer 2: Arthrocentesis is appropriate in the management of septic arthritis which presents with an exquisitely tender hip in a child who refuses to bear weight. The hip will be red, hot, and tender and there is severe pain with passive range of motion. The CRP and ESR are often elevated and treatment involves antibiotics and surgical washout.

Answer 2: CT scan may better characterize avascular necrosis and is more sensitive than a radiograph and less sensitive than a MRI in working up this condition. It is not the most appropriate initial step.

Answer 3: Ibuprofen and acetaminophen is appropriate management of transient synovitis of the hip which presents with hip pain after a viral illness. Children may complain of hip pain and may walk with a limp; however, they are still willing to bear wait and the joint appears normal. There is no reduced range of motion in this condition.

Answer 4: MRI is the most accurate test in the diagnosis of avascular necrosis of the hip and could be used in cases where the diagnosis is uncertain.

Bullet Summary:
The most appropriate initial step in management in the workup of avascular necrosis is a radiograph.