Femoral shaft bowing with age: a digital radiological study of Anatolian Caucasian adults

Abstract

Purpose: To determine the dimensions of the femoral shaft and their relationship to age in Anatolian Caucasian men and women.

Materials and methods: Maximum femoral length (MFL), mid-shaft transverse diameter (MTD), and anterior bowing (AB) were studied in a sample of 104 adults. The linear dimensions and AB of the femoral shafts were measured on digital images.

Results: In males, mean MFL, MTD, and AB were 448.2 mm, 26.5 mm, and 759.3 mm, respectively. In females these measurements were 419.0 mm, 25.6 mm, and 779.5 mm. Males had longer MFL (P < 0.0001) and there was no difference between males and females regarding the other parameters. MFL and age were correlated in females (r = -0.374, P < 0.005), whereas they were not correlated in males. In females, MFL decreased until about 45 years of age and stabilized thereafter. MTD was correlated with age in males (r = 0.428, P < 0.002), increasing from adolescence to maturity. This correlation was insignificant in females and there was only a slight increase in diameter after about 30 years of age. AB and age were significantly correlated in females (r = -0.401, P < 0.003), with AB continuously increasing with age. The correlation between AB and age was insignificant in males.

Conclusion: The increase in bone cross-sectional area in aging males may contribute to the maintenance of adequate mechanical competence throughout adulthood. In females this compensatory mechanism appears to be much less efficient and, accordingly, the end result of this process is AB of the femur and inevitable shortening of the bone.