We have developed a method for determining the extent of avascularity of
the capital femoral epiphysis in suspected Legg-Calve-Perthes disease. The
avascularity is expressed quantitatively as a percentage of the normal
uptake of a radionuclide in the vicinity of the involved hip. In
twenty-seven patients who had radionuclide scintigraphy this method was
reliable in establishing an early diagnosis of Legg-Calve-Perthes disease
as well as in assessing the amount of involvement of the femoral head. In
some patients the diagnosis can be established by radionuclide scintigraphy
before the changes of Legg-Calve-Perthes disease are apparent on standard
radiographs.