Systematic Reviews
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Oct 28, 2019; 10(11): 394-403
Published online Oct 28, 2019. doi: 10.5312/wjo.v10.i11.394
Magnetically controlled growing instrumentation for early onset scoliosis: Caution needed when interpreting the literature
Kenneth Aaron Shaw, Justin M Hire, Scott Kim, Dennis P Devito, Michael L Schmitz, Joshua S Murphy
Kenneth Aaron Shaw, Department of Orthopaedic Surgery, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA 30905, United States
Justin M Hire, Department of Orthopaedic Surgery, General Leonard Wood Army Community Hospital, Fort Leonard Wood, MO 65473, United States
Scott Kim, University of Tennessee Health Science Center, Memphis, TN 38163, United States
Dennis P Devito, Michael L Schmitz, Joshua S Murphy, Department of Pediatric Orthopaedic Surgery, Children’s Healthcare of Atlanta, Scottish Rite Campus, Atlanta, GA 30342, United States
Author contributions: Shaw KA, Devito DP, Schmitz ML and Murphy JS designed research; Shaw KA, Hire JM and Kim S performed research; Shaw KA analyzed data; Shaw KA, Hire JM and Murphy JS wrote the paper.
Conflict-of-interest statement: Each author certifies that he or she has no commercial associations that might pose a conflict of interest in connection with the submitted article. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of Defense or US Government.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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:
Corresponding author: Kenneth Aaron Shaw, MD, Assistant Professor, Surgeon, Department of Orthopaedic Surgery, Dwight D. Eisenhower Army Medical Center, 300 East Hospital Road, Fort Gordon, GA 30905, United States.
Telephone: +1-706-7876158 Fax: +1-706-7872901
Received: May 5, 2019
Peer-review started: May 8, 2019
First decision: July 31, 2019
Revised: September 6, 2019
Accepted: October 7, 2019
Article in press: October 7, 2019
Published online: October 28, 2019
Research background

Although the outcomes of using magnetically controlled growing rods (MCGR) to treat early onset scoliosis (EOS) has been reviewed, these studies do not take into account important implants modifications, termed iterations, that were made due to early on postoperative complications is not well reported or understood.

Research motivation

To gain a deeper understanding of how modification to MCGR after affected patients outcomes for the treatment of EOS and the implications of these effects on the reporting of future MCGR.

Research objectives

To assess the effect of MCGR implant iterations on post-operative complications in EOS.

Research methods

A systematic review was performed to identify studies investigating MCGR specifically for the treatment of EOS, refined to those reporting the implant iteration, specifically the incorporation of the keeper plate to the implant design. Articles with mixed implant iteration usage were excluded. Complications following surgery were recorded as well as potential risk factors and compared between implant cohorts.

Research results

Although 20 articles were identified for inclusion, 5 (25%) included mixed implant iteration leaving a total of 271 patients identified through 15 clinical studies that met inclusion criteria. Pre-keeper plate implants were utilized in 3 studies with a total of 49 patients. Overall, 115 (42.4%) post-operative complications were identified, with 87% defined as major. The addition of the keeper plate significantly decreased the rate of post-operative complications per study (35.7% vs 80.6%, P = 0.036), and the rate of distraction failure (8.1% vs 40.8%, P = 0.02). Unplanned reoperation occurred in 69 (26.7%) patients but was not different between implant iteration cohorts (25.5% without keeper plate vs 27.1% with keeper plate, P = 0.92).

Research conclusions

MCGR implant with Keeper plates have less post-operative distraction failures. Of the currently published studies, 25% include mixed implant designs. Future studies reporting on MCGR outcomes should include implant iteration in their analysis. MCGR implant with Keeper plates have less post-operative distraction failures. Of the currently published studies, 25% include mixed implant designs. Studies included mixed implant iterations could be artificially inflating postoperative complication rates. Have more recent implant modification exhibited similar effects on MCGR outcomes. Twenty-five percent of currently published studies on MCGR outcomes included mixed implant iterations which could be artificially inflating complication rates. The addition of the keeper plate has decreased the incidence of distraction failure in the treatment of EOS. Understanding implant design gives important insight to understanding how they affect patient outcomes.

Research perspectives

Future studies should include implant iterations in the reporting of MCGR outcomes for the treatment of EOS. Long-term follow-up of children treated with MCGR for EOS. Subdividing MCGR outcomes by implant iteration will help ensure complications rates are not artificially inflated.