Abstract
Among the changes in the femoral shaft after Charnley THR, hypertrophic change of the cortex was studied from the view point of bone remodeling and pathogenesis of cortex hypertrophy were discussed.
The subjects were 23 femurs in which cortex hypertrophy occurred during the follow-up period after THR. Occurrence of cortex hypertrophy began two years after THR, and 91% of 23 femurs had it by 6 years after THR. In the cases with varus position of the stem, cortex hypertrophy was observed much more in lateral cortex, however, in the cases with valgus and neutral position of the stem, there was no consistent tendency in the location of the hypertrophy. The mean age at the time of THR in the cases with cortex hypertrophy was younger than that in the cases with atrophy.
It was suspected that as the etiology of cortex hypertrophy after Charnley THR, a lot of factors such as activity after THR, body weight, stem position and bone remodeling, might be involved.
