Retrospective Cohort Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Apr 18, 2023; 14(4): 218-230
Published online Apr 18, 2023. doi: 10.5312/wjo.v14.i4.218
Clinical outcomes of cemented distal femur replacements with all-polyethylene tibial components for oncologic indications
Alexander B Christ, Brian C Chung, Matthew Urness, Lucas W Mayer, Brandon S Gettleman, Nathanael D Heckmann, Lawrence R Menendez
Alexander B Christ, Brian C Chung, Matthew Urness, Lucas W Mayer, Nathanael D Heckmann, Lawrence R Menendez, Department of Orthopedic Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, United States
Brandon S Gettleman, University of South Carolina School of Medicine, Columbia, SC 29209, United States
Author contributions: Christ AB, Menendez LR, and Heckmann ND generated the idea, provided guidance throughout, were heavily involved in copy-editing, and oversaw execution of the project; Chung BC, Urness M, Mayer L, and Gettleman BS were responsible for data collection, literature review, statistical analysis, and drafting the manuscript; All authors listed read and approved the final manuscript.
Institutional review board statement: Proposal #HS-20-00396 indicates that this study is determined to be IRB exempt.
Informed consent statement: The study is IRB-exempt at our institution because we did not employ the use of humans and the use of their protected health information for this study was deemed minimal risk. Thus, an Informed Consent form is not applicable for this study.
Conflict-of-interest statement: One of the authors (N.D.H.) is a paid consultant for Intellijoint Surgical and MicroPort Orthopedics, has stock options from Intellijoint Surgical, and is a committee member of AAOS and AJRR. One of the authors (L.R.M.) is a paid consultant for Onkos Surgical and receives IP royalties from TeDan Surgical. Each author certifies that he has no commercial associations that might pose a conflict of interest in connection with the submitted article. One of the authors (A.B.C) is a board member for AAOS, Musculoskeletal Tumor Society, Orthopaedic Society. (A.B.C) is also a paid consultant for Smith and Nephew, Intellijoint Surgical, and Enovis.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement – checklist of items, and the manuscript was prepared and revised according to the STROBE Statement – checklist of items.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Alexander B Christ, MD, Doctor, Department of Orthopedic Surgery, Keck School of Medicine of University of Southern California, 1500 San Pablo Street, Los Angeles, CA 90033, United States. alexander.b.christ@gmail.com
Received: January 13, 2023
Peer-review started: January 13, 2023
First decision: February 2, 2023
Revised: February 10, 2023
Accepted: April 4, 2023
Article in press: April 4, 2023
Published online: April 18, 2023
ARTICLE HIGHLIGHTS
Research background

Future prospective studies with larger sample sizes and longer term followup are necessary to determine the optimal construct for oncologic distal femoral replacement (DFR). Comparative studies investigating the differences in clinical, functional, and patient-reported outcomes between the use of metal-backed vs all-polyethylene tibial components and cemented vs cementless fixation will provide further insight into the specific failure mechanisms associated with each construct.

Research motivation

This study proposes that DFR with all-polyethylene tibial (APT) is a reliable reconstruction option for oncologic defects of the distal femur.

Research objectives

DFR with APT implantation was performed as a primary procedure in 29 patients (52.7%) and a revision procedure in 26 patients (47.3%). Overall, twenty patients (36.4%) experienced a postoperative complication requiring reoperation. In total, 12 patients (21.8%) required a revision while 20 patients (36.4%) required a reoperation, resulting in three-year cumulative incidences of 24.0% (95%CI 9.9%-41.4%) and 47.2% (95%CI 27.5%-64.5%), respectively.

Research methods

A retrospective review of consecutive patients who underwent DFR with a GMRS® (Global Modular Replacement System, Stryker, Kalamazoo, MI, United States) cemented distal femoral endoprosthesis and APT component for an oncologic indication was performed using a single-institutional database. Univariate analyses were performed to compare differences between those who had a DFR performed either as the primary treatment for the disease in question vs those who had a DFR as a revision of a previous failed surgery (indications included recurrence, fracture, etc.). Competing risk analyses were performed to evaluate the cumulative incidence of all-cause reoperation, need for revision surgery, and patient death.

Research results

This study was designed to answer the following research questions: (1) What are the most common modes of implant failure for patients undergoing cemented DFR with APT for oncologic indications? (2) What is the survivorship, rate of all-cause reoperation, and rate of revision for aseptic loosening of these implants? and (3) Is there a difference in implant survivorship or patient demographics between cemented DFRs with APT performed as a primary reconstruction vs those performed as a revision procedure?

Research conclusions

Prior studies investigating the outcomes of endoprosthetic distal femoral replacement have largely failed to describe the type of tibial component or fixation used. Unlike the femoral component, tibial components are available in both metal-backed and all-polyethylene designs, and fixation may be achieved via cemented, cementless, or hybrid fixation. Future research investigating the effect of tibial component design and fixation on clinical outcomes is critical to determining the optimal construct for oncologic DFR.

Research perspectives

Endoprosthetic reconstruction of the distal femur has been used as a limb-salvage procedure to treat oncologic processes of the distal femur for nearly five decades, and is currently considered standard of practice for this indication. However, there is a paucity of literature examining the survivorship of DFRs with respect to the type of tibial component utilized. The purpose of this study was to report on the clinical outcomes of patients undergoing cemented DFR with all-polyethylene tibial components for oncologic indications.