Biomechanical properties of a magnesium alloy absorbable rib intramedullary nail / 中国组织工程研究

ABSTRACT

BACKGROUND: At present, the materials that are successful y applied in rib fracture internal fixation mainly include titanium, nitinol rib encircling bone bonding plate, imported poly-L-lactic acid absorbable rib nails and anatomical plate. OBJECTIVE: To study the biomechanical characteristics of new magnesium al oy absorbable rib intramedul ary nail in the rib fracture fixation, and to compare with imported poly-L-lactic acid absorbable rib intramedul ary nail in order to provide scientific basis for clinical application. METHODS: Thirty fresh adult fifth rib specimens were col ected, and the specimens were used to make models for the middle rib fractures. The specimens were fixed with AZ31B magnesium al oy absorbable rib intramedul ary nail (magnesium al oy group) and poly-L-lactic acid absorbable rib intramedul ary nail (poly-L-lactic acid group), and the normal rib specimen group was set as control. The biomechanical characteristics of the nails in each group were tested with stress analysis. RESULTS AND CONCLUSION: Three-point bending strength measurement results showed that the bending strength in the magnesium alloy group was close to the normal value of the specimen (P > 0.05), and there was significant difference in the bending strength between magnesium alloy group and the poly-L-lactic acid group (P < 0.05). Torsional strength measurement showed that there was no significant difference in torsional strength between magnesium alloy group and the normal specimens, and the results showed that the magnesium alloy was better than poly-L-lactic acid in fixation (P < 0.05). Tensile tests showed that the tensile strength and anti-pulling force of the magnesium alloy fixation were better than those of poly-L-lactic acid fixation (P < 0.05). The results indicate that the magnesium alloy absorbable rib intramedullary nail is better than poly-L-lactic acid absorbable rib intramedullary nail in strength and tensile strength, which is the ideal fixation material for rib fixation.