Conference Agenda

Osseointegrated transfemoral prostheses directly anchor the implant into the residual femur, eliminating the complications of socket-based systems. How-ever, the mechanical behaviour of the bone-implant interface critically gov-erns periprosthetic bone remodelling. Most finite element studies simplify this interface as fully bonded, overlooking the spatially heterogeneous nature of os-seointegration. This study evaluates the influence of contact condition, fric-tional versus bonded, and implant geometry on periprosthetic bone remodel-ing, comparing three transfemoral stem designs: straight, planar-curvature, and double planar-curvature. An iterative finite element framework coupled with a gradient-enhanced bone remodelling algorithm was employed, using strain en-ergy density as the mechanical stimulus. Under bonded contact, all designs showed approximately 19% bone density reduction across most Gruen zones, with no meaningful differences among geometries. Frictional contact produced lower resorption (≈16% in Gz6 for BPC implant) and revealed clear geometric sensitivity: the patient-specific designs achieved less resorption (16–18% ranges,), while the straight one showed the widest density reduction (18–19%). These findings demonstrate that interface modelling assumptions critically af-fect simulation outcomes, and that patient-specific curved stem geometries may offer biomechanical advantages over straight designs.