Biomedical implant design is a structural-mechanics problem first: an implant must bear repeated physiological loads for decades without excessive deflection, fatigue cracking, or overloading the surrounding tissue.
deflection ~ load / stiffness (beam theory)
safety_factor = yield_stress / max_stress
- Truss segments — how the implant's internal lattice/strut structure is discretized for the load model.
- Material stiffness — elastic modulus of the implant material (titanium alloy, PEEK composite) resisting deformation.
- Physiological load — the moving body-weight-driven force the implant must bear during gait or activity.
- Load cycling speed — how fast the load moves along the implant, as in a walking gait cycle.
Titanium hip stems are deliberately engineered with lower stiffness than solid metal (via porous lattices) specifically to reduce 'stress shielding' — where an overly stiff implant carries so much load that surrounding bone weakens from disuse.