Introduction

We are pleased to announce the publication of our research study, “Does the ratio of stem-to-femur length matter? A validated finite element analysis,” in the Journal of Experimental Orthopaedics.

Key Findings

This work experimentally validated our patient-specific finite element model against a cadaver study using Digital Image Correlation. The validated model was then employed in a large-scale parametric analysis of 1300 implant configurations across 100 femora, enabled by the automated design of our software, which ensured consistent and accurate generation of each personalized stem.

The central finding is a quantitative, biomechanical principle: the optimal stem length to balance initial stability (micromotion) and stress shielding is proportional to the total femur length. This proportionality relationship was consistent across the anatomical variation in the cohort.

Clinical Implications

For surgeons, this provides a data-driven reference for stem length selection in cementless, metaphyseal-fitting stems. For the field, it introduces a measurable criterion that moves beyond a “fill-and-fit” paradigm toward proportional sizing based on patient anatomy.

This research demonstrates the power of computational modeling in orthopedic design and reinforces our approach to developing patient-specific solutions through advanced biomechanical analysis.

About Arthroniq

This study was conducted in collaboration with experts from the University of Thessaly, University of West Attica, and National Technical University of Athens, representing a significant contribution to the field of orthopedic biomechanics and implant design.