Restoration of X-ray bone density when replacing cortical plate defects with a tissue-engineered construct in the experiment

Abstract

Over the past decade, in global practice, the frequency of using high-resolution multi-layer spiral computed tomography (MSCT) for assessing the state of cancellous and cortical bone tissue has significantly increased. Using high-resolution MSCT makes it possible to assess X-ray bone density at various times after replacement of cortical plate defects with osteoplastic materials. The aim of the research. To study the restoration of cortical bone density in the area of osteoplasty using tissue-engineered construct in the experiment. Materials and methods. In an in vivo experiment on New Zeland White (NZW) rabbits, perforation defects of cortical bone were formed in the femoral diaphysis. Three study groups were set up: group 1 – without bone defect replacement; group 2 – with  bone defect replacement with deproteinized cancellous bone; group  3  – with bone defect replacement with tissue-engineered construct based on deproteinized cancellous bone with stromal vascular fraction of adipose tissue. Follow-up periods were 2, 4 and 6 weeks after the surgery. The X-ray density of cortical bone tissue was measured in Hounsfield units (HU). Fragments of deproteinized human cancellous bone were used alone and in combination with the stromal vascular fraction of NZW rabbit adipose tissue as a bone-replacing material for bone defect replacement. Results. Cortical plate density the in the area of the defect in the group 3 by the week 6 is on average 1.3 times lower than that of the intact cortical plate and corresponds to D1 according to Misch classification. Cortical plate density in the area of the defect on the side of medullary canal by the week 6 in the group 3 corresponds to D1 according to Misch classification and is equal to 1351.25 ± 221.18 HU (1052; 1805), which is 1.5  times higher than in group  2 (D2 according to Misch classification; p < 0.05). The obtained results indicate an earlier restoration of X-ray bone density when using a tissue-engineered construct (group 3) compared to the same indicators in groups 1 and 2.