DESIGN OF KNEE JOINT PROSTHETIC ELEMENTS MADE OF COMPOSITES

Abstract

Aim. To develop an innovative four-bar mechanical knee-joint prosthesis made of composites. Materials and methods. Ground reaction force measurements were taken with the Xsens motion capture system, involving a healthy volunteer and an individual with a prosthetic leg walking on a treadmill at 3 km/h. The specimen of epoxy resin fiberglass was used for bar testing. A 3D model of the Total Knee 1000/2000 knee joint prosthesis (Össur, Iceland) was generated using the SolidWorks package. Mechanical testing of a bar element was carried out with the Instron 5900R, and stress-strain analysis of both the model specimen and the 3D knee joint prosthesis was conducted using the finite element method (ANSYS package). Results. A new construction of a four-bar mechanical knee-joint prosthesis made of composites was proposed. Based on the data obtained from individuals walking on a treadmill at 3 km/h, the study shows that the prosthesis experiences significant compressive loads only in the heel-to-toe phase. In this case, the load on the prosthesis can be twice the weight of a person. The new design of the knee prosthesis involves the use of high-strength fiberglass in the bar elements instead of the expensive titanium and aluminum alloys of a similar prosthesis from Össur (Iceland). Calculation of loads in prosthetic elements and experiments on model specimens show that new bar elements can have a weight two to three times less than that of the analogue. This allows us to consider composites as promising for the manufacture of new specimens of knee prostheses.