Is axial shape of distal femur different in normal and osteoarthritic female patients?

OBJECTIVES: This study aims to investigate whether the axial shape of the distal femur is different between normal and osteoarthritic female knees using statistical shape analysis.

PATIENTS AND METHODS: A total of 126 knee magnetic resonance images of 126 female patients were examined in this study conducted between May 2013 and May 2014. Patients were divided into two groups as study and control groups. The study group consisted of 41 patients (median age 65 years; min. 36 - max. 88 years) who were determined to have knee osteoarthritis, while the control group consisted of 85 patients (median age 43 years; min. 20 - max. 81 years) without knee osteoarthritis. Anatomic and constructive landmarks were selected and marked on each two-dimensional digital image in the axial section of the distal femur. The mean axial shapes of the distal femur were compared between the groups by statistical shape analysis. Shape deformations were investigated by thin plate spline analysis.

RESULTS: There were significant differences between the groups regarding the axial shape of the distal femur. Maximal deformation was observed in the femoral notch area.

CONCLUSION: This study showed that there are deformations in the axial shape of the distal femur in female patients with knee osteoarthritis. Further studies are required to determine whether these differences are important for implant design and surgical technique of total knee replacement.