N Degen1, J Sass2, J Jalali3, L Kovacs4, E Euler2, W C Prall5, W Böcker2, P H Thaller3, J Fürmetz3. 1. Department of General, Trauma and Reconstructive Surgery, University Hospital, LMU Munich, Germany. Electronic address: nikolaus.degen@med.lmu.de. 2. Research Group CAPS - Computer Aided Plastic Surgery, Department of Plastic Surgery and Hand Surgery, University Hospital Klinikum rechts der Isar, Technical University Munich, Germany. 3. Department of General, Trauma and Reconstructive Surgery, University Hospital, LMU Munich, Germany. 4. FIFA Medical Center of Excellence, Division of Knee, Hip and Shoulder Surgery, Schoen Clinic Munich Harlaching, Academic Teaching Hospital of the Paracelsus Medical University (PMU), Salzburg, Austria. 5. Research Group CAPS - Computer Aided Plastic Surgery, Department of Plastic Surgery and Hand Surgery, University Hospital Klinikum rechts der Isar, Technical University Munich, Germany; FIFA Medical Center of Excellence, Division of Knee, Hip and Shoulder Surgery, Schoen Clinic Munich Harlaching, Academic Teaching Hospital of the Paracelsus Medical University (PMU), Salzburg, Austria.
Abstract
BACKGROUND: Three-dimensional (3D) preoperative planning and assisted surgery is increasingly popular in deformity surgery and arthroplasty. Reference ranges for 3D lower limb alignment are needed as a prerequisite for standardized analysis of alignment and preoperative planning in 3D, but are not yet established. METHODS: On 60 3D bone models of the lower limbs based on computed tomography data, fifteen parameters per leg were assessed by standardized validated 3D analysis. Distribution parameters and differences between sexes were evaluated. Reference values were generated by adding/subtracting one standard deviation from the mean. RESULTS: Women had a significantly lower mean mechanical lateral distal femoral angle compared with men (86.4 ± 2.1° vs. 87.8 ± 2.0°; P < .05) and significantly lower mean joint line convergence angle (-2.5 ± 1.4° vs. -1.3 ± 1.2; P < .01), but higher mean hip knee ankle angle (178.9 ± 1.9° vs. 177.8 ± 2.3°; P < .05) and mean femoral torsion (18.2 ± 9.5° vs. 13.2 ± 6.4°; P < .05), resulting in a tendency towards valgus alignment and vice versa for men. Differences in mean medial proximal tibial angle were not significant. The mean mechanical axis deviation from the tibial knee joint center was 6.9 ± 7.3 mm medial and 1.4 ± 16.1 mm ventral without significant differences between sexes. CONCLUSIONS: We describe total and sex-related reference ranges for all alignment relevant axes and joint angles of the lower limb. There are sex-related differences in certain alignment parameters, which should be considered in analysis and surgical planning.
BACKGROUND: Three-dimensional (3D) preoperative planning and assisted surgery is increasingly popular in deformity surgery and arthroplasty. Reference ranges for 3D lower limb alignment are needed as a prerequisite for standardized analysis of alignment and preoperative planning in 3D, but are not yet established. METHODS: On 60 3D bone models of the lower limbs based on computed tomography data, fifteen parameters per leg were assessed by standardized validated 3D analysis. Distribution parameters and differences between sexes were evaluated. Reference values were generated by adding/subtracting one standard deviation from the mean. RESULTS:Women had a significantly lower mean mechanical lateral distal femoral angle compared with men (86.4 ± 2.1° vs. 87.8 ± 2.0°; P < .05) and significantly lower mean joint line convergence angle (-2.5 ± 1.4° vs. -1.3 ± 1.2; P < .01), but higher mean hip knee ankle angle (178.9 ± 1.9° vs. 177.8 ± 2.3°; P < .05) and mean femoral torsion (18.2 ± 9.5° vs. 13.2 ± 6.4°; P < .05), resulting in a tendency towards valgus alignment and vice versa for men. Differences in mean medial proximal tibial angle were not significant. The mean mechanical axis deviation from the tibial knee joint center was 6.9 ± 7.3 mm medial and 1.4 ± 16.1 mm ventral without significant differences between sexes. CONCLUSIONS: We describe total and sex-related reference ranges for all alignment relevant axes and joint angles of the lower limb. There are sex-related differences in certain alignment parameters, which should be considered in analysis and surgical planning.
Authors: Maximilian Jörgens; Alexander M Keppler; Philipp Ahrens; Wolf Christian Prall; Marcel Bergstraesser; Andreas T Bachmeier; Christian Zeckey; Adrian Cavalcanti Kußmaul; Wolfgang Böcker; Julian Fürmetz Journal: Eur J Trauma Emerg Surg Date: 2022-07-26 Impact factor: 2.374