Is sexual dimorphism in morphometric variables of the proximal femur moderated by age in adulthood? A cross-sectional study in Ghana

Ageing may impact proximal femoral morphometry in both males and females. However, it is not clear whether the observed sexual dimorphism is attributable to an ageing effect in the post-pubertal period. The potential effect of ageing on sexual dimorphism in the proximal femur is most significantly relevant for forensic and osteoarchaeological research. The study was cross-sectional and comprised 123 participants (females = 72 and males = 51), who were recorded between January 2017 and June 2018 at the Korle-Bu Teaching Hospital. The study participants were aged between 31 and 79 years. The femoral head diameter, the femoral neck diameter, the femoral neck-shaft angle, and the femoral hip axis length were measured from the right side by radiographic technique and following standard osteometry methods. The femoral head-neck ratio was then calculated. All measurements were taken twice and then averaged. The (mean ± SD) femoral head diameter was higher in males (5.1 ± 0.56 cm) than in females (4.8 ± 0.51 cm) with a moderate effect size (p = 0.023, Hedge’s g = 0.56). Similarly, the femoral neck diameter was higher in males (4.0 ± 0.52 cm) than in females (3.8 ± 0.48 cm) with a small effect size (p = 0.025, Hedge’s g = 0.40). The femoral head axis length increased by 0.03 cm annually in males. The observed sexual dimorphism in the femoral head and neck diameters could not, however, be attributable to the ageing effect. Ageing may not have an impact on sexual dimorphism in the femoral head and neck diameters among persons older than 30 years in the Ghanaian population.