Bone structural similarity score: a multiparametric tool to match properties of biomimetic bone substitutes with their target tissues.

The research presents the development of a quantitative bone structural similarity score (BSSS) that aids in matching the structural and mechanical properties of synthetic grafts with bone tissue for bone substitution surgery or tissue engineering. This score helps overcome challenges due to the variation in tissue properties arising from factors like anatomical site, patient’s sex, age, and health conditions.

Research Methodology

• The study involved comparison of two biocompatible hydroxyapatite porous scaffolds having different pore sizes with trabecular bone tissues from equine humerus and femur.
• All sample structures were imaged using high-resolution micro-computed tomography which was then analyzed to estimate the properties including porosity, pore size distribution, interconnectivity, specific surface area, connectivity density, and degree of anisotropy.
• Further measuring of Young’s modulus and stress at break were conducted through compression tests.
• Structural similarity distances between sample pairs were calculated based on scaled and weighted differences of the measured properties to assess feasibility for scoring structural similarity.

Research Findings

• Statistical measures like Manhattan distances and Quadrance demonstrated consistent similarities between sample pairs with a discriminating capacity similar to image-based scores. These were more effective than simple statistical comparisons.
• The score was found capable of assessing progression of pathologies impacting bone structure.

Conclusions

• The results of the research indicate the potential to define a quantitative and objective bone structural similarity score.
• This tool could assist biomaterials scientists in fabricating and surgeons in selecting the graft or scaffold optimally matching the structure of a specific bone tissue.