Hip Osteonecrosis (Legg-Calve-Perthes)

7 y/o Caucasian M with h/o low birth weight, perinatal HIV infection, sickle cell disease presents with insidious onset hip and knee pain. Parents report progressive, decreased hip ROM and intermittent antalgic gait; no fever. Decreased abduction and internal rotation of hip on exam.

• Radiography showing femoral head lucency and subchondral sclerosis/collapse

• MRI showing osteonecrosis of the femoral head

• Refer to pediatric orthopedics

Notes

• Risk factors

  • Age

    • May occur in patients age 2-12 years

    • Most common in children age 4-8 years

    • Poor prognosis in children older than 6 years

  • Sex: 5 times more common in boys

  • Race: More common in white as compared to black children

• Pathophysiology: Avascular necrosis of the femoral head

• Presentation

  • Pain can be referred to knee

  • Antalgic gait may be intermittent