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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.
IMAGING FINDINGS:
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
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
DIFFERENTIAL DIAGNOSIS:
Septic arthritis
Toxic synovitis
Osteomyelitis
Langerhans cell histiocytosis
Slipped capital femoral epiphysis
Juvenile rheumatoid arthritis
TREATMENT:
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. PROGNOSIS:
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.