Automated femoral version estimation without the distal femur

Abstract

Femoral version impacts the long-term functioning of the femoroacetabular joint. Accurate measurements of version are thus required for success in total hip arthroplasties and hip reconstructive surgeries. These are impossible to obtain without visualization of the distal femur, which is often unavailable preoperatively as the majority of imaging scans are isolated to the pelvis and proximal femur. We developed an automated algorithm for identifying the major landmarks of the femur. These landmarks were then used to identify proximal axes and create a statistical shape model of the proximal femur across 144 asymptomatic femora. With six proximal axes selected, and 200 parameters (distances and angles between points) from the shape model measured, the best-fitting linear correlation was found. The difference between true version and version predicted by this model was 0.00 ± 5.13° with a maximum overestimation and underestimation of 11.80 and 15.35°, respectively. The mean absolute difference was 4.14°. This model and its prediction of femoral version are a substantial improvement over pre-operative 2D or intra-operative visual estimation measures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Femur morphometry and correlation between proximal and distal parts

“…Geometric harmony between the prosthesis and the resected surface of the knee is critical for the long-term success of total knee arthroplasty 10 . Proper orientation of the femoral head and neck is necessary for the biomechanical function of the hip joint 7 .…”

“…The inclination angle is formed by the femoral neck axis and the femoral shaft axis in the frontal plane. The femoral version is defined as the anterior deviation of the neck axis from the posterior condylar line 7 .…”

Capturing the 2019 H. R. Lissner Medal Presentation With Jennifer S. Wayne

“…The last computational work discussed was the development of an automated system to provide 3D analysis of important hip measures for diagnosis and pre-operative planning purposes directly the CT scanned pelvis and hip [19][20][21]. The algorithms developed identify critical bony features-pubic tubercle, ASIS (anterior superior iliac spine), AIIS (anterior inferior iliac spine), and acetabular rim-from the pelvis.…”

Correlation between lag screw route and the ideal insertion point of the intramedullary nail

“…For example, when inserting the short femoral nail to surgically treat intertrochanteric fractures of the femur or determining the entry point and anteversion of the femoral stem in total hip arthroplasty (THA), knowledge of the superior aspect of the proximal femur anatomy is necessary. Previous studies have investigated the morphology of the femur 1 – 6 . A cadaveric study investigated the greater trochanter morphology and assessed the optimal insertion point of the intramedullary nail; however, there was no information on a correlation between the route of the lag screw and the ideal insertion point of the intramedullary nail 5 .…”