Influence of biomaterial structure and hardness on its osseo-integration: histomorphometric evaluation of porous nitinol and titanium implants

摘要

The aim of this research was to evaluate and compare the bone integration and apposition capacities of two metallic intervertebral fusion implants, porous nitinol (PNT: porous Nickel Titanium Naval Ordonance Laboratory) and titanium intervertebral cage, in the sheep lumbar spine. Sixteen sheep received two implants each at L2-L3 and L4-L5 lumbar levels so as to subject both the implants to the same mechanical loads. The sheep were then sacrificed at 3, 6 and 12 months post-implantation periods. Lumbar segments were then harvested. A qualitative (macroscopic and microscopic observation) and quantitative (histomorphometric) analysis of bone integration and apposition was carried out on histological slides. The results indicated that the PNT obtained the better bone integration and apposition compared to titanium cage. The osseo-integration of each implant seemed to be influenced by its structure and its hardness. However, the biocompatibility of two implants seemed comparable.