Evidence map›Paper›PMID 42199851›Full record

ArticleNorth American Spine Society journal2026

Ex vivo mechanical evaluation of anatomically and mechanically conforming patient-specific lumbar spinal fusion cages designed by full-scale topology optimization.

Xiaoyu Du, Thijs Smit, Wolfgang Rubin, Charles Cheruparambil, Rahul Shah, Daniel Haschtmann, Benedikt Helgason, Stephen J Ferguson

Abstract read
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Article in North American Spine Society journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Xiaoyu DuInstitute for Biomechanics, ETH Zurich, Gloriastrasse 37, 8092 Zurich, Switzerland.
Thijs SmitInstitute for Biomechanics, ETH Zurich, Gloriastrasse 37, 8092 Zurich, Switzerland.
Wolfgang RubinLaboratory of Metal Physics and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
Charles CheruparambilInstitute for Biomechanics, ETH Zurich, Gloriastrasse 37, 8092 Zurich, Switzerland.
Rahul ShahInterventional Spine Team, Premier Orthopaedic Associates, 352 S. Delsea Drive, Suite C, Vineland, NJ 08360, USA.
Daniel HaschtmannDepartment of Spine Surgery, Schulthess Klinik, Lengghalde 2, 8008 Zurich, Switzerland.
Benedikt HelgasonInstitute for Biomechanics, ETH Zurich, Gloriastrasse 37, 8092 Zurich, Switzerland.
Stephen J FergusonInstitute for Biomechanics, ETH Zurich, Gloriastrasse 37, 8092 Zurich, Switzerland.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Intervertebral disc degeneration may require spinal fusion surgery using interbody cages. Implant subsidence remains a significant complication, largely attributed to the stiffness mismatch between interbody cages and vertebral endplates. While porous cage designs aim to reduce their stiffness, they do not account for patient-specific anatomical and mechanical variability. This study aims to evaluate whether patient-specific, topology optimized interbody cages improve load distribution and decrease subsidence risk compared with off-the-shelf cages in a human cadaveric mechanical model. Methods: Sixteen functional spinal units (FSUs) were allocated by bone quality to topology-optimized devices (TOD) or off-the-shelf (OTS) cage groups. Both cage types were designed for a TLIF approach (TOD by a previously developed topology optimization method) with the same footprint and additively manufactured from medical-grade titanium alloy. Endplate contact was assessed using pressure-sensitive film. FSUs underwent axial compression to failure at 1 mm/min with optical displacement tracking. Failure (subsidence) force is defined as the first local maximum of the force-displacement curve. Results: Pressure film analysis demonstrated broader and more uniform endplate contact for TOD cages, whereas OTS cages exhibited concentrated edge loading. Failure (subsidence) force and integral volumetric bone mineral density (vBMD) were positively correlated for both cage groups. Paired comparisons showed a significantly higher failure (subsidence) force (increase of median force by 97.6%) for TOD implants (median force: 876.5 N) compared to OTS implants (median force: 443.7 N; p = .03). Conclusions: Patient-specific topology optimized interbody cages improved endplate conformity and load distribution, resulting in higher resistance to subsidence compared to conventional off-the-shelf cages. These findings suggest that patient-specific topology optimized interbody cages may offer a biomechanically advantageous solution for spinal fusion, especially in patients with compromised bone quality, with the potential to reduce implant subsidence and improve clinical outcomes.

Indexed as

Biomechanical testingCageEx vivoHuman cadaver testingImplantLumbarPatient-specificSpinal fusionTLIFTopology optimization

Identifiers

PMID42199851
PMCPMC13199957

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.