Femur Co-Variance Analysis

Introduction: Natural procurvatum of the femur along with torsional abnormalities pose limitations towards accurate measurement of femoral varus and anatomic lateral distal femoral angle (aLDFA) when surgically planning for distal femoral osteotomy (DFO). The purpose of this study was to describe and quantify the effect of measurements taken in frontal (aLDFA), sagittal (CORONA1 as a substitute for other measurements) and axial planes (anteversion). We hypothesized that when the anteversion angle (AA) changes the aLDFA and procurvatum measurements will change and vice versa.

Materials and Methods: A clinically normal anatomic canine femur was used to collect three planes of measurements utilizing commercial digital software (blender). Fourteen copies of the femur were created, and a distal osteotomy was performed to create varying AA in 5-degree increments to evaluate subsequent effects on aLDFA and procurvatum. Measurements were performed in the frontal, sagittal and axial planes.

Results: The changes in AA do not have a linear impact on procurvatum or aLDFA. Alterations to aLDFA do not change other measurements when perspective remains constant.

Discussion/Conclusion: The data supports the utilization of CT scans with computer-assisted planning and the development of surgical guides to more accurately plan for DFOs in dogs.

Acknowledgment

None.

Publication History

Article published online:
15 July 2025