Skeleton-Based 3D Femur Shape Analysis System Using Maximum-Minimum Centre Approach

Abstract

Femoral shaft fractures are correlated with frequent morbidity and mortality. It is a major musculoskeletal disorder caused by tremendous force applied to the femur. One of the most common surgical treatments for fixation is intramedullary nailing (IM), which utilises a specially designed metal rod and screws to be implanted into the medullary canal. However, severe bowing of the femur can result in a mismatch between the IM nail and the alignment of the femur. Such mismatch is a risk factor for anterior cortical perforation off the distal femur with subtrochanteric fractures and leg length discrepancy with fractures of the femoral shaft. Therefore, accurate three-dimensional (3D) preoperative planning is mandatory to facilitate the implant’s design based on the obtained geometric data, especially for the fractured bowed femur. This paper presents an automatic 3D femur shape analysis system (3D-FSA) based on the extracted skeleton of each individual patient to provide an accurate 3D preoperative simulation. The structure of the 3D femur was generated using a set of computed tomography (CT) images. By using the maximum-minimum centre approach for skeletonization, significant geometric and topological information was captured. The proposed approach can potentially assist in implant measurements.

Keywords

• CT images
• femoral shaft fractures
• intramedullary nail
• internal fixation surgery
• measurement analysis
• medial axis transform