Ethnic-, gender-, and age-related differences in femorotibial angle, femoral antetorsion, and tibiofibular torsion: cross-sectional study among healthy Japanese and Australian Caucasians.

The current study was conducted to examine ethnic, gender, and age-related differences in femorotibial angle (FTA), femoral antetorsion and tibiofibular torsion. Healthy Japanese (n = 120) and Australian Caucasian (n = 82) subjects were examined using a series of clinically reliable methods for measuring FTA and torsion of the lower limb. Subjects between 18-29 years of age were categorized as younger, 30-59 years as middle age, and 60 or more as older age. Three-way analysis of variance was utilized for data analysis. The Japanese subjects had significantly greater FTA (more varus) than the Australian subjects (P < 0.001). Femoral antetorsion in the Japanese subjects was significantly smaller in middle and older age groups than younger group (P < 0.05), but did not differ between the age groups in the Australian subjects. Further, tibiofibular torsion in female subjects was significantly greater in younger and middle age groups than the older age group (P < 0.01), but was not different between different age groups in males. The results suggest that healthy Japanese may have more genu varus alignment compared to the corresponding Australian population. Age-related ethnic and gender differences in femoral and tibiofibular torsion are worthy of further study.