Design and biomechanical evaluation of a novel connective rod for revision surgery

English Keywords:Reoperation  Model validation  Spinal fusion  Biomechanics

English Abstract:

  【Abstract】 Objectives: To design a novel connective rod for revision surgery by using an end to end connection joint, and to evaluate their biomechanical characters. Methods: Following the guidelines of American society for testing and materials(ASTM), static compression bending test, static tension bending test, fatigue test was employed on both conventional rod(group A, n=6) and connective rod for revision surgery(group B, n=6) to measure the bending yield load, bending stiffness and maximum run-out load, and to determine the biomechanical stability of novel connective rod. Results: In static compression bending test, compressive bending yield load and compressive bending stiffness of group A were 865.60±25.71N and 52.35±0.38N/mm respectively; while they were 863.20±11.01N and 52.92±2.43N/mm in group B, the differences between groups had no statistical significance. In static tension bending test, tensile bending yield load and tensile bending stiffness of group A were 1184.20±30.14N and 58.89±3.01N/mm respectively; and for group B, they were 1169.20±14.89N and 57.48±1.47N/mm respectively, the differences between groups had no statistical significance. In fatigue test, the maximum run-out load of group A and group B was 303N and 302N respectively, the difference between groups had no statistical significance. Conclusions: Compared with the conventional connective rod, the novel connective rod for revision surgery has a similar bending yield load, bending stiffness and maximum run-out load.