Early Avascular Necrosis

D. Brady Pregerson, MD

Pain in the right hip that had gradually worsened within the past month prompted a 42-year-old man to seek medical attention. The pain was aggravated by lifting the right leg and by walking; it was relieved by ibuprofen. The patient denied recent trauma, fever, overexertion, numbness, leg weakness, and back pain. He had had a discectomy for a herniated lumbar disk several years earlier. There was no history of sickle cell disease or allergies. He reported occasional alcohol use.

 

Pain in the right hip that had gradually worsened within the past month prompted a 42-year-old man to seek medical attention. The pain was aggravated by lifting the right leg and by walking; it was relieved by ibuprofen. The patient denied recent trauma, fever, overexertion, numbness, leg weakness, and back pain. He had had a discectomy for a herniated lumbar disk several years earlier. There was no history of sickle cell disease or allergies. He reported occasional alcohol use.

The patient's vital signs were normal. He had a mild limp. The right hip demonstrated full range of motion, but both active and passive movement elicited pain. The remainder of the physical examination findings were normal.

A radiograph of the pelvis revealed patchy sclerosis in the femoral heads bilaterally that was more prominent on the right side (arrow). D. Brady Pregerson, MD, of Los Angeles reports that these findings were consistent with early avascular necrosis of the right hip.

Nontraumatic avascular necrosis (bone, or aseptic, necrosis) occurs primarily in the hip and shoulder joints. Affected patients may have a limp and pain that worsens with activity. Risk factors include use of corticosteroids, excessive alcohol use, blood dyscrasia (eg, sickle cell disease, thalassemia), Gaucher disease, and scuba diving.

Radiographs may show patchy sclerosis early in the disease, although radiographic findings may lag 2 weeks behind symptom onset. In advanced disease, subchondral bone resorption can lead to a "crescent sign," which may be followed by flattening of the femoral head, collapse, and eventually, secondary arthritic changes. MRI is the most effective modality for evaluating avascular necrosis and can help rule out other conditions, such as metastatic disease and occult stress fractures.

Treatment initially consists of rest and management of the primary disease. Some orthopedists recommend core decompression surgery; however, patients with disease progression often require joint replacement surgery.

This patient was given non-weight-bearing crutches and was advised to discontinue use of alcohol. An appointment with an orthopedist was scheduled, but the patient was lost to follow-up.