Femoral Offset and its Relationship to Femoral Neck-shaft Angle and Torsion Angle

The aims to study the femoral offset and its relationship to femoral neck-shaft angle and torsion angle. One hundred paired (50 males and 50 females) Chinese femurs were used to measure the femoral offset, femoral neck-shaft angle and torsion angle. The data were analyzed by SPSS software. Femoral offsets were male right 44.40 +/- 4.56 mm, left 42.70 +/- 4.95 mm; female right 39.90 +/- 6.00 mm, left 38.90 +/- 6.18 mm. Femoral torsion angles were male right 6.02 +/- 10.85 degrees, left 7.08 +/- 9.30 degrees; female right 10.02 +/- 11.69, degrees left 6.02 +/- 10.85 degrees. Neck-shaft angles were male right 131.80 +/- 4.36 degrees, left 134.00 +/- 4.78 degrees; female right 132.10 +/- 5.94 degrees, left 132.80 +/- 4.93 degrees. There were no sexual differences in the two femoral angles (P>0.05) while there was a significant sexual difference in the femoral offset (P<0.01). The differences between left and right femoral offset and neck-shaft angle were significant (P<0.01). Clinically, our results indicate that FO could be obtained using the regression equation when the torsion angle and/or neck-shaft angle is measured.