Influence of a non-biodegradable porous structure on bone repair

Abstract

Pore and interconnection size are two key structural parameters for bone tissue engineering scaffolds. In the present study, four hydroxyapatite (HA) bioceramic scaffolds with similar pore size (500–600 μm) but different interconnection sizes (100, 120, 150 and 200 μm), and three HA scaffolds with similar interconnection size (120 μm) but different pore sizes (400–500, 500–600 and 600–700 μm) were implanted into distal femoral condyle defects for 72 rabbits. The results showed that volume of new bone increased proportionally to the interconnection size. However, significant differences between interconnection size groups were only observed at week 24. Smaller pore size showed significantly more new bone formation at week 4, whereas no significant differences between the three pore size groups were found at weeks 12 and 24. In conclusion, large interconnection size facilitates new bone formation and a minimum size of 120 μm is recommended. Although small pore size improves bone ingrowth at early time points, pore size has limited impact on bone ingrowth later.