Functional Knee Phenotypes of Patients Operated on for Total Knee Arthroplasty. Comparison With a Reference Non Arthritic Population

Methods Five hundred and four navigated total knee arthroplasties will be analyzed. The following angles will be measured with a computer image free navigation system: medial femorotibial mechanical angle without stress and with maximum manual stress to reduce deformation, and medial distal femoral mechanical angle. The native medial distal femoral and medial proximal tibial angles will be calculated. The data will be analyzed as numerical and categorical data. These data will be then compared with those published in a non-arthritic population, considered as a control group.

The main criterion will be the percentage of subjects with normal overall coronal alignment, defined by the association of a normal native medial distal femoral angle and a normal native medial proximal tibial angle. The secondary criteria will be the percentages of subjects with normal medial femorotibial mechanical angle, normal native medial distal femoral angle and normal native medial proximal tibial angle. The influence of gender on primary and secondary criteria in the study group will be analyzed. The most frequent phenotypes in the study group will be identified.