Coronal and sagittal alignment of the lower limb in Caucasians: of a 3D CT database

Introduction: Lower limb alignment is a major determinant of long-term outcomes after osteotomy or total knee replacement. The aim of this paper is to define the mean values of coronal and sagittal lower limb alignment for Caucasians as a function of sex using 3D reconstructions from CT-scans. Materials and methods: The analysis involved 586 Caucasian patients (269 males and 317 females) who had their hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior proximal tibial angle (PPTA), lateral and medial proximal posterior tibial angles (LPPTA/MPPTA), posterior distal femoral angle (PDFA), and non-weightbearing joint convergence angle (nwJLCA) measured. This analysis was performed using a CT-scan-based modelling system (SOMA). Differences between sexes and morphotypes (neutral, varus and valgus) were analyzed statistically. Results: The mean HKA was 180 +/- 2.57 degrees, LDFA 86.1 +/- 1.87 degrees, MPTA 86.1 +/- 2.15 degrees, PPTA 84.6 +/- 2.58 degrees, LPPTA 84.9 +/- 3.17 degrees, MPPTA 85.1 +/- 3.21 degrees, PDFA 85.3 +/- 1.50 degrees and nwJLCA 0.82 +/- 1.32 degrees. There was a significant difference between sexes for the HKA (180.3 +/- 2.46 degrees and 179.0 +/- 2.52 degrees), LDFA (85.6 +/- 1.90 degrees and 86.8 +/- 1.61 degrees), MPPTA (84.7 +/- 3.06 degrees and 85.6 +/- 3.31 degrees). The neutral morphotype was more frequent in women than men (78% vs. 73%), the varus morphotype was more frequent in men than women (20% vs. 7.6%) and the valgus morphotype was more frequent in women than men (15% vs. 6.7%). Conclusion: Normal parameters for lower limb alignment in Caucasian patients were described in the coronal and sagittal planes. There was a significant influence of sex in the coronal plane, which was not found in the sagittal plane. (C) 2022 Published by Elsevier Masson SAS.