Stress shielding is the reduction in bone density (osteopenia) as a result of removal of typical stress from the bone by an implant (for instance, the femoral component of a hip prosthesis).[1] This is because by Wolff's law,[2] bone in a healthy person or animal remodels in response to the loads it is placed under. It is possible to mention the elastic modulus of magnesium (41–45 GPa) compared to titanium (110–127 GPa), stainless steel (189–205 GPa), iron (211.4 GPa), or zinc (78–121 GPa), which makes it further analogous to the natural bone of the body (3–20 GPa) and prevents stress shielding phenomena.[3][4] Porous implantation is one typical alleviation method.[5][6]
^Frost, HM (1994). "Wolff's Law and bone's structural adaptations to mechanical usage: an overview for clinicians". The Angle Orthodontist. 64 (3): 175–188. PMID8060014.
^US patent 5702449, William F. McKay, "Reinforced porous spinal implants", published 1997-12-30, issued 1997-12-30, assigned to Danek Medical, Inc., Memphis, Tenn. and SDGI Holdings Inc.