Clinical significance of the relationship between 3D analysis of the distal femur and femoral shaft anatomy in total knee arthroplasty

Abstract

Objectives: A proper morphometric analysis of the anatomy of the distal femur is of utmost importance for providing correct alignment for the survival of total knee arthroplasty (TKA). Herein, we aimed to conduct a detailed morphometric analysis of the distal femur, including the differences between men and women. We also aimed to determine landmarks in thesagittal and coronal planes for positioning of the femoral component during TKA and demonstrate the data that may affectclinical outcome.Methods: Two-hundred adult femurs from the collection of anatomy department were enrolled in this study. Three-dimensionalreconstruction of computed tomography scans were performed on these femurs. Differences between the reference axes andlines in the sagittal and coronal planes were obtained from the images, and correlation coefficients of the collected data wereanalyzed. All measurements were compared between men and women.Results: The calculated mean angles between the sagittal mechanical axis, anterior cortical axis and distal medullary axis werefound as 5.14±1.67° and 4.12±2.41°, respectively, and the mean angle difference between the posterior condylar line (PCL) andthe epicondylar axis (EA) was 4.37±2.18°. The angle difference between PCL and EA was higher in females (p=0.047).Conclusion: In addition to the gender-dependent anthropomorphic differences between the distal femurs of females andmales, differences between the measurements used as reference in conventional TKA techniques may affect the post-operative alignment.