Relationship Between Coronal Plane Alignment of the Knee Phenotypes and Distal Femoral Rotation
Year: 2025
Type: article
Study design: Observational Study
Abstract: Background: The Coronal Plane Alignment of the Knee (CPAK) classification categorises nine phenotypes based on constitutional limb alignment and joint line obliquity and can be used in healthy and arthritic knees. In total knee arthroplasty surgery, some morphological variables in planes other than the coronal are particularly interesting. For example, the distal femoral rotation. Our study aimed to search for relationships between phenotypes based on CPAK classification and distal femoral rotation. Methods: Data from 622 cases in 535 osteoarthritic patients who underwent primary total knee arthroplasty have been retrospectively analysed. Computed tomography imaging was employed to ascertain the mechanical lateral distal femoral angle, the mechanical medial proximal tibial angle and the distal femoral rotation (quantified using the condylar twist angle). Results: The variables are perfectly uncorrelated according to the regression equations, with a Coefficient of Determination of 0.0608 for the condylar twist angle. Upon visualising the condylar twist angle function using a contour map or surface curves with low interpolation, it becomes evident that the data do not follow any discernible pattern. Employing ANOVA, we found some statistically significant differences between the distributions of the CPAK groups for the condylar twist angle (F = 5.81; p < 0.001). Conclusions: Our study found no relevant relationships between coronal plane alignment, according to the CPAK classification and the distal femoral rotation in the sample population studied. Perhaps the stratification of the CPAK groups (i.e., a purely arithmetical aspect) hides possible relationships between the coronal and the axial planes.
Source: Journal of Clinical Medicine
DOI: 10.3390/jcm14051679
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4408121834