Estimation of pretraumatic femoral antetorsion in bilateral femoral shaft fractures

Objective To describe a system for measurement of the pretraumatic femoral antetorsion angle post-bilateral femoral shaft fracture with the use of new imaging software which allows segmentation and three dimensional (3D) reconstruction of DICOM (digital imaging and communications in medicine) images. Material and methods This case involved a 20-year-old patient with bilateral femoral shaft fractures. Following initial clinical examination, CT scans of both femurs were performed. Subsequently, the DICOM datasets were uploaded to the new software tool. Following segmentation and 3D reconstruction, pretraumatic femoral antetorsion angles were determined. Results Femoral antetorsion was described and assessed in two ways by referring to the intersection of the posterior condylar plane and (1) a line drawn between the center of the femoral head and femoral neck, (2) a line drawn between the centers of the femoral head and greater trochanter. Using these definitions, values for femoral antetorsion were found to be, respectively, 20 at the right fracture site and 19 on the left site, and 33 bilaterally. Discussion The investigators describe in this current technical report the use of new imaging software which enables the calculation of femoral AV following reduction of virtual fracture fragments which are created from standard DICOM images. We believe that this 3D reconstruction method of measuring the antetorsion angle can be integrated into a regular treatment algorithm and may potentially optimize clinical outcomes.