Computed tomography measurement of femoral neck anteversion in South Asian adult population: A records -based study at a tertiary care hospital

Abstract Background: Femoral neck anteversion (FNA) angle, the angular relationship between the femoral neck and the distal femoral condyles, plays a critical role in hip biomechanics and surgical planning. Variations in FNA are associated with gait abnormalities, hip dislocations, and influence implant alignment in orthopedic procedures. While normative FNA data exists for Western populations, limited reference data is available for South Asian adults. Objective: To measure the femoral neck anteversion angle in a South Asian adult population using computed tomography (CT) and compare findings with established literature. Methods: This records-based study was conducted at Mandya Institute of Medical Sciences, Karnataka, using pre-existing CT scans of the hip and femur. FNA was calculated by superimposing axial CT images of the femoral head-neck and distal femoral condyles. A total of 83 femurs (from adults aged 18–80 years) were analyzed. Statistical comparisons were made by sex, side, and age groups. Results: The mean FNA was 17.57° ± 13.16°. Males (n=43) had a mean FNA of 17.65°, while females (n=40) had 17.48°, with no statistically significant difference (p = 0.954). A significant side-wise difference was noted, with left femurs showing higher anteversion (21.28° ± 6.69°) than right femurs (15.67° ± 15.16°, p = 0.022). No significant differences were observed across age groups (p = 0.120). Conclusion: The FNA values in this South Asian cohort align with global reference ranges, demonstrating high inter-individual variation but no significant influence of age or sex. The observed laterality difference suggests potential anatomical asymmetry, underscoring the importance of individualized assessment during orthopaedic surgical planning. These findings may support regional considerations in implant design and clinical decision-making.