Exploring design strategies for patient-specific bone scaffolds to create a uniform mechanical environment in
Andrea Fresquet-Monter1, Ricardo Belda1, Ana Vercher-Martínez1
1Institute of Mechanical Engineering and Biomechanics- I2MB, Department of Mechanical Engineering and Materials, Universitat Politècnica de València, Camino de Vera, s/n, Valencia, 46022, Spain.
Background And Objective:
Large bone defects cannot be repaired by the inherent regeneration mechanisms of bone due to their size, which makes medical intervention essential. Current therapeutic treatments have their limitations, which has led to the study and development of bone scaffolds that maintain structural integrity during bone healing. Novel designs are required to create a mechanical environment that promote osseointegration. In this work, we aim to analyse the effect of patient-specific designs on the creation of a uniform mechanical environment in bone-scaffold constructs.
Methods:
Novel patient-specific Triply Periodic Minimal Surface (TPMS) structures were designed according to the characterisation of the microstructure of healthy and osteoporotic human cancellous bone to mimic morphometry. In addition, the assessment of the TPMS representative volume element size was also considered for scaffold design. The interaction between bone and scaffold was analysed through finite element model simulation. In those bone-scaffold assemblies we evaluated three different design strategies: (1) matching bone microstructure; (2) similar apparent compression elastic modulus; and (3) mimicking both the morphometry and the apparent modulus of trabecular bone.
Results:
The stress distribution in patient-specific TPMS scaffolds is 83.86 % similar to that of the targeted bone, significantly outperforming the 54.41 % similarity of non-patient-specific solutions.
Conclusions:
The design of novel patient-specific scaffolds based on a microstructure similar to cancellous bone allows a uniform stress distribution. Hence, matching both the bone morphometry and apparent elastic modulus is a key issue to reducing stress shielding phenomena and inducing osseointegration.
