Orthopedic screw parameters in the orthogonal test: Biocompatibility evaluation
10.3969/j.issn.2095-4344.1887
- Author:
Dengyan LONG
1
Author Information
1. College of Mechanical and Electrical Engineering, Hohal University
- Publication Type:Journal Article
- Keywords:
Analysis of variance;
Biocompatiblllty;
Finite element analysis;
Intuitive analysis;
Orthogonal experiment;
Orthopedic screw;
Stress transfer parameter;
Weight matrix method
- From:
Chinese Journal of Tissue Engineering Research
2020;24(10):1574-1579
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Most current studies of orthopedic screw parameters focus on mechanical properties but lack biocompatiblllty assessment. OBJECTIVE: To Investigate the Influence of geometric parameters and material properties of orthopedic screws on blomechanical compatibility, explore the optimal combination of various factors and parameterization levels, providing a theoretical reference for the design of orthopedic screws. METHODS: An orthogonal experiment protocol was designed according to the five factors and three parameterization levels of orthopedic screws. Factor A was the screw diameter (4.5, 5.5, 6.5 mm), factor В was thread profile (rectangular, trapezoidal, triangular), factor С was screw pitch (1.75, 2.25, 2.75 mm), factor D was the thread depth (0.5,1.0,1.5 mm), and factor E was elastic modulus (45,110, 200 GPa). The blomechanical finite element analysis of the three-dimensional bone-nail model under different sets of screw parameters was carried out. Stress distribution and two experimental indicators (the stress transfer parameter STPa between the cortical bone and the screw, and the stress transfer parameter STPß between the cancellous bone and the screw) under different experimental schemes were obtained. The weighted matrix analysis method was used to analyze the orthogonal experimental data to obtain the influence law and the optimal combination. RESULTS AND CONCLUSION: Different levels of different factors have different degrees of influence on biocompatiblllty. Among them, the screw material properties are the most Important factors, followed by the thread profile, pitch and thread diameter, and the last was the thread depth. The thread profile, pitch, and thread diameter had similar influence on biocompatiblllty. The optimal combination of the orthogonal experiment was an orthopedic screw with a large diameter of 6.5 mm, a trapezoidal thread, a pitch of 2.75 mm, a thread depth of 0.5 mm, and an elastic modulus of 45 GPa.
