The Effects of Rod Bending Method and Metal Type on Fatigue Strength and Corrosion in Posterolateral Lumbar Fusion

Samantha Corman; Yumeng Gao; Nicole DeVries Watson; Doug Fredericks; Catherine Olinger

doi:10.1177/21925682261422665

Back

The Effects of Rod Bending Method and Metal Type on Fatigue Strength and Corrosion in Posterolateral Lumbar Fusion

Journal article

Open access

Peer reviewed

The Effects of Rod Bending Method and Metal Type on Fatigue Strength and Corrosion in Posterolateral Lumbar Fusion

Samantha Corman, Yumeng Gao, Nicole DeVries Watson, Doug Fredericks and Catherine Olinger

Global spine journal

02/05/2026

DOI: 10.1177/21925682261422665

PMCID: PMC12875886

PMID: 41641751

Files and links (1)

url

https://doi.org/10.1177/21925682261422665View

Published (Version of record) Open Access

Abstract

Study Design Basic Science Study.Objectives To determine the impact of rod composition and bending method on metal debris production during fatigue testing of posterolateral lumbar fusion constructs.Methods Posterolateral lumbar fusion constructs were embedded into Ultra-High Molecular Weight Polyethylene (UHMW-PE) blocks and subject to fatigue testing, following a modified ASTM F1717-21 protocol including cycles of compression with novel axial rotation. Variations in constructs included rod bending methods of pre-bent (PB) and surgeon-bent (SB) and rod compositions of titanium alloy (Ti) or cobalt chromium alloy (CC). Constructs were wrapped in lactated ringer solution-soaked cotton, which was dissolved and analyzed for metal particulate using inductively coupled mass spectrometry (ICP-MS).Results Metal debris produced by surgeon-bent cobalt chromium and pre-bent cobalt chromium constructs did not have significant differences in quantity or quality. Pre-bent cobalt chromium alloy rods produced a larger amount of chromium and cobalt metal debris than pre-bent titanium alloy rods.Conclusions We find that cobalt chromium alloy rods produce more metal debris than titanium alloy rods. We find no evidence that rod bending method affects metal debris quality or quantity. In considering factors that impact susceptibility to corrosion and metallosis, our data supports that rod composition, but not bending method, contributes significantly to metal debris production.

Orthopedics

Clinical Neurology

Life Sciences & Biomedicine

Neurosciences & Neurology

Science & Technology

Details

Title: Subtitle: The Effects of Rod Bending Method and Metal Type on Fatigue Strength and Corrosion in Posterolateral Lumbar Fusion
Creators: Samantha Corman - University of Iowa
Yumeng Gao - University of Iowa
Nicole DeVries Watson - University of Iowa, Orthopedics and Rehabilitation
Doug Fredericks - University of Iowa, Craniofacial Anomalies Research Center
Catherine Olinger - University of Iowa
Resource Type: Journal article
Publication Details: Global spine journal
DOI: 10.1177/21925682261422665
PMID: 41641751
PMCID: PMC12875886
NLM abbreviation: Global Spine J
ISSN: 2192-5682
eISSN: 2192-5690
Publisher: Sage
Number of pages: 8
Language: English
Electronic publication date: 02/05/2026
Academic Unit: Orthopedics and Rehabilitation; Craniofacial Anomalies Research Center; Neurosurgery
Record Identifier: 9985139487802771

Metrics

3 Record Views