Effect of head size and rotation on taper corrosion in a hip simulator.

Content Provider	Europe PMC
Author	Wight, Christian M. Whyne, Cari M. Bogoch, Earl R. Zdero, Radovan Chapman, Ryan M. van Citters, Douglas W. Walsh, William R. Schemitsch, Emil
Copyright Year	2021
Abstract	AimsThis study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads.MethodsIn all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth.ResultsOverall, 36 mm heads had lower corrosion onset load (p = 0.009) and change in open circuit potential (OCP) during simulated gait with (p = 0.006) and without joint movement (p = 0.004). Discontinuing gait’s joint movement decreased corrosion currents (p = 0.042); however, wear testing showed no significant effect of joint movement on taper damage. In addition, 36 mm heads had greater corrosion area (p = 0.050), but no significant difference was found for maximum linear wear depth (p = 0.155).ConclusionLarger heads are more susceptible to taper corrosion; however, not due to frictional torque as hypothesized. An alternative hypothesis of taper flexural rigidity differential is proposed. Further studies are necessary to investigate the clinical significance and underlying mechanism of this finding.Cite this article: Bone Jt Open 2021;2(11):1004–1016.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC8636299&blobtype=pdf
Journal	Bone & Joint Open [Bone Jt Open]
Volume Number	2
PubMed Central reference number	PMC8636299
Issue Number	11
PubMed reference number	34825826
e-ISSN	26331462
DOI	10.1302/2633-1462.211.bjo-2021-0147.r1
Language	English
Publisher	The British Editorial Society of Bone & Joint Surgery
Publisher Date	2021-11-01
Publisher Place	London
Access Restriction	Open
Rights License	This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (CC BY-NC-ND 4.0) licence, which permits the copying and redistribution of the work only, and provided the original author and source are credited. See https://creativecommons.org/licenses/by-nc-nd/4.0/ © 2021 Author(s) et al.
Subject Keyword	Fretting Corrosion Hip simulator Metal-on-polyethylene Total hip arthroplasty Frictional torque polyethylene head-neck taper corrosion cobalt chrome head titanium stem Femoral head ANOVA metal-on-polyethylene metals larger femoral heads
Content Type	Text
Resource Type	Article
Subject	Orthopedics and Sports Medicine Surgery