Case of the Week: August 21-August 28, 2002

5 year old with Hip Pain, Limp and Limited Motion.

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Case Details

Plain Film: There is flattening and sclerosis and irregular mineralization of the right femoral head. NM Bone Scan: Decreased tracer uptake is evident in the region of the right femoral head


Diagnosis: Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes disease is also known as idiopathic avascular necrosis of the hip. It is a condition resulting from idiopathic infarction of the bony epiphysis of the femoral head. The most frequent age range of presentation is 5-8 years (when the femoral head is most susceptible to interruption of vascular supply). The condition is often associated with skeletal immaturity. There is a male predominance, with a male:female ratio of 5:1. The disease is usually asymmetric, but can be bilateral in 13%--usually sequential, rather than recurrent. The usual symptoms are limp, with groin, thigh or knee pain.


Plain radiographs (PF) are typically positive at the time of presentation, even early.

Early findings: 

  • Widened joint space

    • With joint effusion or synovial hypertrophy

  • Subchondral linear lucency

    • Crescent sign

    • Best seen on frog-leg views

    • Represents fracture through necrotic bone

Late findings:

  • Fragmentation of femoral epiphysis

  • Increased sclerosis/lucency of femoral epiphysis

  • Loss of height (collapse) of femoral epiphysis

Chronic findings:

  • Broad, overgrown femoral head (coxa magna)

  • Short femoral neck

  • Physeal arrest

NM Scintigraphy:

  • Early: Decreased tracer uptake due to interruption of blood supply

  • Late Increased tracer uptake due to revascularization/repair

MR Imaging:

  • Image both hips - look for asymmetric appearance of femoral epiphysis

  • Hypointense epiphyseal marrow center on T1-weighted images

  • Marrow edema on T2-weighted images


  • Septic arthritis

  • Toxic synovitis

  • Osteomyelitis

  • Langerhans cell histiocytosis

  • Slipped capital femoral epiphysis

  • Juvenile rheumatoid arthritis


Treatment and significance of radiographic findings is controversial. Approximately 50% will improve with no treatment. Others may require bracing or a femoral osteotomy. Acetabular reconstruction may be required to provide coverage of the femoral head. 


Younger age at presentation yields A better prognosis. Findings associated with poor prognosis include: Female gender, calcification/lytic area lateral to the epiphysis, metaphyseal lucency, increased epiphyseal extrusion at greater than 20%, and greater than 50% femoral head involvement. 86% of children will develop osteoarthritis.

Correct answers by users

VCU Resident
Radiology Pediatrics
VCU Department of Pediatric Radiology Virginia Commonwealth University VCU Medical Center