Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The stages of evolution of Perthes’ disease. The early part of the disease is from the onset till Stage IIa (early fragmentation stage). The late part of the disease is from Stage IIb to Stage IIIb. Intervention aimed at preventing femoral head deformation is only feasible during the early part of the disease
