预紧力作用下钛合金人工假体界面骨小梁形态参数测量与统计分析.

BACKGROUND: The implantation of titanium alloy prosthesis would produce stress shielding to damage mechanical microenvironment of bone tissue. This might affect normal bone remodeling process. Interference fit was used to generate preload to reconstruct mechanical microenvironment in this area. It may have important theoretical significance and clinical application value to promote bone remodeling in the mid-long-term after surgery. OBJECTIVE: To analyze the promoting effect of preload on osseointegration of porous titanium alloy prosthesis. METHODS: Fourteen male New Zealand rabbits were divided into two groups. The three-dimensional (3D) printed titanium alloy prosthesis was implanted into the outside of right femoral condyle with interference fit in experimental group (n=7). Rabbits in the control group (n=7) were feed free. Femurs at the surgery side were extracted at 12 weeks after surgery. Micro-CT scanning and 3D reconstruction were performed to measure bone density and trabecular morphological parameters around the prosthesis. Animal experiment was approved by Animal Ethics Committee of Tianjin Institute of Medical Science (approval No. IMPS-EAEP-Z-2019108-01). RESULTS AND CONCLUSION: (1) Bone mineral density was reduced significantly in the experimental group compared with the control group (P < 0.05). (2) Bone volume fraction, trabecular thickness, trabecular number were reduced in the experimental group compared with the control group (P < 0.05). Bone surface area ratio and trabecular separation were larger in the experimental group than those in the control group (P < 0.05). There was no significant change in degree of anisotropy between the two groups (P > 0.05). (3) The results showed that preload could promote osseointegration of porous titanium alloy prosthesis. However, the structural characteristics of the in-growth bone were worse than healthy bone. This might lead to a high fracture risk in the mid-long-term after surgery. [ABSTRACT FROM AUTHOR]