Femoral varus: an important component in late-onset Blount's disease.

Femoral varus has proven a significant deformity in late-onset Blount's disease. In a retrospective study, six adolescent patients demonstrated mean femoral varus deformity of 10 degrees (range 5 degrees-16 degrees) more than the calculated ideal femoral joint angle (p less than 0.01). This represented between 34 and 76% of the net genu vara deformity of the affected limbs. In the eight infantile patients, all genu vara deformity was in the tibia. The significance of femoral varus should be determined for each patient afflicted with late-onset genu vara preoperatively to avoid compensatory deformity.