Effect of Femoral Stem Modular Neck’s Material on Metal Ion Release
Janie Barry, Marc-Olivier Kiss, Vincent Massé, Martin Lavigne, Jihad Matta, Pascal-Andre Vendittoli*
Hôpital Maisonneuve-Rosemont, Université de Montréal, 5415 Boulevard de l’Assomption, Montreal, Canada
In recent decades, the popularity of modular necks in total hip arthroplasty (THA) has increased since modular necks offer the potential to restore the patient’s native anatomy, and thus improve stability. Unfortunately, modular necks are associated with higher complication rates, including implant fracture and modular junction corrosion with adverse local tissue reaction to metal debris.
The objective of this study was to determine the impact of modular neck material on titanium (Ti), chrome (Cr), and cobalt (Co) metal ion levels in patients who underwent a THA with Ti femoral stem, Ti or CrCo modular neck, and ceramic-on-ceramic (CoC) bearing.
Whole blood Ti, Cr, and Co levels were compared at a minimum 1-year follow-up in 36 patients who underwent unilateral, primary CoC large-diameter head THA with Profemur® Preserve modular femoral stems (MicroPort, Arlington, TX, USA).
Higher Co concentrations were observed in the CrCo modular neck group (0.46 versus 0.26 µg/l in the Ti neck group, P=0.004) and higher Ti concentrations were observed in the Ti modular neck group (1.98 vs 1.59 µg/l in the CrCo neck group, P=0.007). However, these differences were not clinically meaningful since the absolute values remained within what is considered the safe range of Ti, Cr, and Co ions in whole blood. No patients were re-operated or revised.
Modular neck materials had an impact on whole blood metal ion levels but the concentrations measured remained within the safe range at 1-year follow-up. There were no indirect signs of modular junction corrosion with either CrCo or Ti femoral necks.
Keywords: Ceramic-on-ceramic, Metal ions, Modular neck, Total hip arthroplasty, Corrosion, Taper junction.
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
* Address correspondence to this author at the Maisonneuve-Rosemont Hospital, Montreal university, 5415 Boulevard de l'Assomption, Montreal, Canada; Tel: +15142523400; E-mail: email@example.com