Definition
Legg–Calvé–Perthes disease is idiopathic avascular necrosis of the capital femoral epiphysis in children.
Epidemiology
- most often presents between 4 and 8 years
- boys are affected more commonly
- bilateral disease occurs in a minority
Clinical features
- limp
- hip, thigh or referred knee pain
- restricted abduction and internal rotation
- Trendelenburg gait in more advanced disease
Imaging
- AP pelvis and frog-leg lateral radiographs
- early films may be normal
- MRI can detect early disease when radiographs are inconclusive
Stages
The disease progresses through:
- initial / necrotic phase
- fragmentation
- reossification
- healed / residual phase
Prognostic factors
Worse prognosis is associated with:
- older age at onset
- greater femoral head involvement
- lateral extrusion
- loss of hip motion
- adverse radiographic signs
Treatment principles
The aim is to maintain hip motion and contain the femoral head within the acetabulum while remodelling occurs.
- younger children with limited involvement may be observed
- physiotherapy maintains motion
- containment surgery may be considered in older children or more extensive disease