Abstract: 

Despite the clinical success of tapered splined titanium stems, a knowledge gap still exists between spline design and its primary mechanical stability, which is critical to the long-term success of revision hip arthroplasty. Additionally, almost all published pre-clinical studies relied on resource-intensive benchtop and cadaveric testing. Hence, the present study developed a novel computational model to investigate effects of spline geometry and configuration on axial and torsional stability of tapered stem. Dynamic explicit Finite Element Analysis coupled with a state-of-the-art adaptive meshing technique (Abaqus) was used to simulate the highly non-linear contacts and large bony material deformations. Hybridising primary straight splines with secondary angled splines results in 41% and 10% increases of peak insertion force and post-seating moment than the predicate device for the same seating position. The primary straight splines cut at multiple circumferential bony locations, enhancing torsional stability; while the alternatively placed secondary angled splines form wedges with the bone, providing reliable seating and additional torsional resistance. To the best knowledge of the author, this is the first in-silico investigation of its kind to simulate multi-strike seating and torsional resistance of revision hip stems, offering an effective and efficient platform for future multi-factorial parametric study and uncertainty quantification.

Presenter: 

Lin Wang Staff Engineer Digital - Johnson & Johnson MedTech Dr. Lin Wang, a 2025 SIMULIA Champion, whose professional career began in 2008, is passionate about Computational Modelling and Simulation in research & development across various fields. In 2016, he joined DePuy Synthes (J&J MedTech), prior to which he has worked at Cummins Turbo Technologies, Durham University and Spincraft ETG. He also serves as board members of the IMechE Structural Technology & Materials Group and NAFEMS Computational Structural Mechanics Working Group. He is a certified 6 sigma black belt and a chartered engineer, member of IMechE. He holds a PhD of Mechanical Engineering from Durham University. Lin has 16 years’ experience with SIMULIA products (Abaqus, FE-Safe, Tosca) in solving challenge problems faced by academia and industry. In particular, he is an expert of using Abaqus to simulate highly nonlinear conditions and ultra-large material deformations. So far, he has published 19 peer-reviewed journal and conference articles as the first author with approx. 400 citations.