Capability of auxetic femoral stems to reduce stress shielding after total hip arthroplasty

Advancement in total hip implant: a comprehensive review of mechanics and performance parameters across diverse novelties

“…This investigation involves fixed flexion angles ranging from 8 to 121 and abduction angles ranging from 6 to 12 degrees. [33][34][35][36][37][38][39][40][41][42][43][44][45] The loading condition plays a significant role in assessing the performance of hip implants. However, the mechanical performance of a hip implant stem within an implanted femur bone was evaluated following ISO-7206-08 guidelines in recent literature.…”

“…In those works, the analysis involved applying axial loads ranging from 600 N to 5 KN on the femoral head. 15,16,33,35,[37][38][39][41][42][43][46][47][48][49][50] In numerous recent studies, dynamic load component values have been utilized to assess the mechanical behaviour of hip implant stems within implanted bones. 12,34,43,45,47,[51][52][53] However, a German study group known as ''Orthoload'' has released dynamic force and moment data of daily activities in various environments.…”

“…15,16,33,35,[37][38][39][41][42][43][46][47][48][49][50] In numerous recent studies, dynamic load component values have been utilized to assess the mechanical behaviour of hip implant stems within implanted bones. 12,34,43,45,47,[51][52][53] However, a German study group known as ''Orthoload'' has released dynamic force and moment data of daily activities in various environments. Comprehensive details of this dataset (Force F and Moment M) are openly accessible on their website.…”

“…Additionally, the safety factor drops as the elastic modulus lowers, but remains within the fatigue limit for hip stems with less than 30% porosity and a dense shell thickness greater than 1.5 mm. Liu et al 43 assessed stress shielding of three different femoral stem models available in the market (Mayo, CLS, and Fitmore), along with exploring various re-entrant angles for the porous structures (60°, 70°, and 80°). The study involved the design of nine femoral stems with porous structures (consisting of three M-type, three C-type, and three F-type variations), alongside three solid femoral stems used as a control group for comparison.…”

2023 January issue Journal of Orthopaedic Translation

“…showed that an auxetic femoral stem reduced SS after THA. The novel solution provided in this study may serve to increase the survival rate of femoral stems by reducing SS after THA [ 10 ]. Cartilage regenerative mechanisms initiated by knee joint distraction (KJD) are incompletely understood.…”