Randomized Controlled Trial
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Oct 18, 2020; 11(10): 442-452
Published online Oct 18, 2020. doi: 10.5312/wjo.v11.i10.442
Highly cross-linked versus conventional polyethylene inserts in total hip arthroplasty, a five-year Roentgen stereophotogrammetric analysis randomised controlled trial
Justin van Loon, Daniël Hoornenborg, Inger Sierevelt, Kim TM Opdam, Gino MMJ Kerkhoffs, Daniël Haverkamp
Justin van Loon, Daniël Hoornenborg, Inger Sierevelt, Daniël Haverkamp, Department of Orthopaedic Surgery, Xpert Orthopedie Amsterdam/Specialized Center of Orthopedic Research and Education, Amsterdam 1101EA, Netherlands
Justin van Loon, Kim TM Opdam, Gino MMJ Kerkhoffs, Department of Orthopaedic Surgery, Amsterdam University Medical Centres, Location Academic Medical Center, Amsterdam 1105AZ, Netherlands
Author contributions: All authors contributed to the study conception and design. Haverkamp D and Hoornenborg D were involved in the initial surgery procedures; writing of the study protocol was performed by Haverkamp D; data collection and analysis were performed by van Loon J and Sierevelt IN; the first draft of the manuscript was written by van Loon J; all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Institutional review board statement: This single center RCT was granted ethical approval by the local ethics committee review board of Slotervaart Hospital (NL23524.048.08).
Clinical trial registration statement: This study is registered at the Dutch Trial Register. The registration identification number is NL5605.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare that there is no conflict of interest.
Data sharing statement: No additional data are available.
CONSORT 2010 statement: The design and reporting of this study were carried out in accordance with the Consolidated Standards of Reporting Trials (CONSORT) principles (see attached CONSORT checklist).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Daniël Haverkamp, MD, PhD, Surgeon, Department of Orthopaedic Surgery, Xpert Orthopedie Amsterdam/Specialized Center of Orthopedic Research and Education, Laarderhoogtweg 12, Amsterdam 1101EA, Netherlands. d.haverkamp@xpertorthopedie.nl
Received: May 19, 2020
Peer-review started: May 19, 2020
First decision: May 26, 2020
Revised: June 3, 2020
Accepted: August 25, 2020
Article in press: August 25, 2020
Published online: October 18, 2020
ARTICLE HIGHLIGHTS
Research background

Highly cross-linked polyethylene (HXLPE) inlay in total hip arthroplasty (THA) is thought to result in lower wear rates in vivo, compared to conventional polyethylene.

Research motivation

More in vivo studies are needed, especially those using Roentgen stereo-photogrammetric analysis (RSA), to confirm the advantage of HXLPE over conventional polyethylene (PE).

Research objectives

The objective of the study was to compare wear of the HXLPE (REXPOL) and conventional PE acetabular inlay with similar ceramic head articulation, within the first five years after implantation.

Research methods

A double-blind randomised controlled trial was performed to compare wear of REXPOL, a HXLPE, with conventional PE within the first five years after implantation using RSA.

Research results

The HXLPE (REXPOL) inlay showed less wear in the latero-medial direction. Significant wear rates of the conventional PE inlay were seen in the latero-medial and center-proximal direction and in volume and corrected volume, whereas the REXPOL inlay did not show this outcome over time.

Research conclusions

Total 3D wear is less with the REXPOL (HXLPE) inlay than with the conventional PE inlay in THAs after five years.

Research perspectives

Further investigations into the long-term wear and factors that might influence wear rates should be conducted, to confirm that HXLPE (REXPOL) can reduce the risk of osteolysis and consequently reduce revision rates in THA. In addition, an investigation of the impact of wear reduction by HXPLE on the functional outcomes of patients is required.