A scaffold design method for femoral defects incorporating Haversian system-inspired architecture: Performance comparison of circumferential and radial canal arrangements.

Abstract

This study aims to develop a versatile scaffold design method for femoral defect repair by integrating a biomimetic scaffold architecture with multi-objective optimization. Two spatial arrangements of Volkmann-like canals, circumferential and radial, are compared for their impact on scaffold performance. The scaffold comprises a cortical-mimicking region designed to mimic the Haversian system, consisting of Haversian-like and Volkmann-like canals, and a medullary cavity-mimicking region filled with a Voronoi tessellation structure. Femoral segment models reconstructed separately from subject-specific CT scans of rats and humans were used to define morphological constraints. Latin hypercube sampling generated 64 design points per scaffold type. Finite element analysis evaluated mechanical properties, and surrogate models combined with NSGA-II were used to optimize mechanical and surface performance. A complex proportional assessment was conducted to compare the two designs. The scaffold's elastic modulus ranged from 7 to 23 GPa. Under comparable conditions, the optimized circumferential canal network scaffold exhibited a yield strength of 88.01 MPa, permeability of 1.624 × 10^-9 m², and specific surface area of 3.97 mm^-1. The radial canal network scaffold exhibited a yield strength of 62.73 MPa, permeability of 4.093 × 10^-9 m², and specific surface area of 3.42 mm^-1. The circumferential arrangement improved mechanical performance, while the radial design provided higher permeability. The complex proportional assessment indicates that the circumferential arrangement of Volkmann-like canals is more suitable for application in femoral defect repair. This method supports elastic modulus-targeted scaffold customization and provides a reference for optimizing and translating bone implants.