Axial and rotational alignment of lower limb in a Caucasian aged non-arthritic cohort

Background: The alignment of human lower limb has been an area of ongoing study for decades. The purpose of this study was to analyze the axial and rotational alignment from hip to ankle in a Caucasian aged non-arthritic cohort. Methods: A non-arthritic cohort of aged patients was retrospectively analyzed by computer tomography. Anatomical–mechanical angle of femur (AMA), femur inclination (FI), femoral anteversion (FA), posterior condylar angle (PCA), proximal tibial torsion (TEAs-PTC and TEAs-PTT) and tibial fibular torsion (PTC-TFA) were measured. Results: The median age of the patients was 76 years (range 67 to 91 years). Regarding axial alignment, the AMA was 5 (2.94; 6.80). No significance differences were reported by side and age. AMA was significantly lower in men. The FI was 125.3 (120.0; 134.8) with no differences in terms of side, age or gender. Regarding torsion alignment, the median values of FA, PTC-TFA and TEAs-PTT were, respectively, 16.8, 28.5 and − 1.4. No differences were reported by age. Right tibia was externally rotated by 1.5 degrees as compared to the left side (P 0.035). Conclusion: The broad variability of the parameters analyzed highlights the necessity for a more anatomical and individualized approach during surgery of lower limb. The present study offers the fundament to understand and treat lower limb deformities. Hence, these data can constitute the normal reference values useful to investigate lower limb malalignment. Moreover, it helps to assess the possible changes of axial and rotational alignment in idiopathic OA of lower limb. Level of evidence III: Retrospective cohort study.