Enhancement of materials for patellar tendon load-bearing orthosis: Design, analysis, and manufacturing study

Abstract

A patellar tendon bearing orthosis (PTBO) is used to support and shift body weight away from the area below the knee. Evaluation of various composite materials, Patellar Tendon Bearing Orthosis was conducted. Important details on the mechanical properties of each group by tensile and fatigue testing. Drawing and analysis PTBO model using Ansys Workbench 17.2. For perlon, the modulus of elasticity (E), yield stress, and ultimate stress were found to be 10.580 MPa, 37.895 MPa, and 1.253 GPa, respectively. Carbon fiber had better mechanical properties, with a modulus of elasticity (E) of 1.958 GPa, a yield stress of 116.878 MPa, and an ultimate stress of 174.163 MPa. In conclusion, Glass fiber displayed an ultimate stress of 99.725 MPa, a yield stress of 90.672 MPa, and a modulus of elasticity (E) of 1.589 GPa. The fatigue resistance of carbon fiber was found to be superior to that of perlon, indicating the extended lifespan made of carbon fiber. The outcomes of the experimental interface pressure tests show that the highest recorded values are on the lateral side (320 kPa) and the posterior side (253 kPa). This shows that the pressure was dispersed uniformly throughout the tissue and away from the bony areas, enhancing walking comfort for the patient. Acceptable in the PTBO model design were the safety factors, total deformation, and (Von-Mises) stress distribution obtained from numerical analysis for the carbon fiber PTBO model, which were 1.49, 0.969 mm, and 86.009 MPa respectively.