Static simulation of polycentric prosthetic knee for structural compliance

The prosthetic knees are exposed to a vertical loading of approximately 5 times the body weight during high-impact activities necessitating a higher safety factor during its design and manufacturing. The static structural simulation of polycentric knee prosthesis to analyze the stress distribution and overall deformation through finite element analysis has been conducted following ISO 10328:2006 standard. The ANSYS Workbench R19.2 is utilized to import the 3D model of polycentric knee. The top extension lever is exposed to static load of 4130 N and the bottom plate is provided with translational constraints. Results have shown lower produced stresses in the front and back joint bars for the loading conditions I and II. The highest measured stress at the front link bush for both load conditions are significantly less than the yield strength of AA7075 employed in the knee design. The maximum observed deformation at various knee components is significantly below the threshold value of 2.5 mm. These findings indicate that this prosthetic knee can withstand enough stress and strain to comply with the structural requirements of ISO 10328:2006.