Perthes Disease
Perthes disease is childhood osteonecrosis of the femoral head caused by interrupted blood supply; the vulnerable head can deform during fragmentation, so preserving hip movement and containment during growth is central to care.
Definition
Perthes disease is idiopathic osteonecrosis of the developing femoral head in childhood, followed by fragmentation, reossification and remodelling. The final shape and function of the hip depend on the extent of involvement and containment during growth.
First principles
The blood supply is interrupted, but the process evolves
Perthes disease begins with interruption of the femoral-head blood supply and osteonecrosis. The head then passes through fragmentation, reossification and remodelling. During the softened phase it is vulnerable to deformation, so a normal-looking early radiograph does not end evaluation when the clinical pattern remains concerning.
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